ATOLL RESEARCH BULLETIN NO. 251 BIOGEOGRAPHY OF THE PUERTO RICAN BANK by Harold Heatwole, Richard Levins and Michael D. Byer Issued by THE SMITHSONIAN INSTITUTION Washington, D. C., U.S.A. July 1981 PUERTO RlCO CULEBRA V I R G I N I S L A N D S Fig. 1. Map of t h e Puer to Rican I s l a n d S h e l f . Rectangles A - E i n d i c a t e boundaries of maps presen ted i n more d e t a i l i n Appendix I. 1. Cayo Sant iago , 2 . Cayo Ba ta t a , 3. Cayo de Afuera, 4. Cayo de T i e r r a , 5 . Cardona Key, 6 . P r o t e s t a n t Key, 7 . Green Key (st . ~ r o i x ) , 8. Caiia Azul ATOLL RESEARCH BULLETIN 251 ERRATUM The following caption should be inserted for figure 7: Fig. 7. Temperature in and near a small clump of vegetation on Cayo Ahogado. Dots: 5 cm deep in soil under clump. Circles: 1 cm deep in soil under clump. Triangles: Soil surface under clump. Squares: Surface of vegetation. X's: Air at center of clump. Broken line indicates intervals of more than one hour between measurements. BIOGEOGRAPHY OF THE PUERTO RICAN BANK by Harold Heatwolel, Richard Levins2 and Michael D. Byer3 INTRODUCTION There has been a recent surge of i n t e r e s t i n the biogeography of archipelagoes owing t o a r e i n t e r p r e t a t i o n of c l a s s i c a l concepts of evolut ion of i n s u l a r populat ions, f a c t o r s con t ro l l ing numbers of species on i s l a n d s , and t h e dynamics of i n t e r - i s l a n d d i spe r sa l . The l i t e r a t u r e on these sub jec t s i s rapidly accumulating; general reviews a r e presented by Mayr (1963) , and Baker and Stebbins (1965) . Car lqu i s t (1965, 1974), Preston (1962 a , b ) , ~ a c ~ r t h u r and Wilson (1963, 1967) , MacArthur et al. (1973) , Hamilton and Rubinoff (1963, 1967), Hamilton et al. (1963) , Crowell (19641, Johnson (1975) , Whitehead and Jones (1969), Simberloff (1969, 19701, Simberloff and Wilson (1969), Wilson and Taylor (19671, Carson (1970), Heatwole and Levins (1973) , Abbott (1974) , Johnson and Raven (1973) and Lynch and Johnson (1974), have provided major impetuses through t h e o r e t i c a l and/ o r general papers on numbers of species on i s l a n d s and t h e dynamics of i n s u l a r biogeography and evolut ion. Other work has d e a l t with s p e c i f i c problems such a s d i spe r sa l ( G r e s s i t t and Yoshimoto 1963, Car lqu i s t 1966 a-c, 1967, Heatwole and Levins 1972b) , i n t e r s p e c i f i c competition (Grant 1965, 1966, 1968, Crowell 1962, 1968, Sheppard et al. 1968) , e f f e c t of d i s a s t e r s (Brat ts trom 1963, Sauer 19621, t rophic r e l a t i o n s (Heatwole 1971, Heatwole and Levins 1972a1, colonizat ion (Bassot and Bal l 1971, Hunt and Hunt 1974, Becker 1975, Schoener 1975 and Williams 19691, and endemism ( ~ a y r 1965, Heatwole and MacKenzie Department of Zoology, Universi ty of New England, Armidale, N.S.W., 2351, Aust ra l ia . Department of Population Sciences, Harvard School of Public Health, 665 Huntington Avenue, Boston, Massachusetts, 02115, U.S.A. Departmento de ~ i o l o ~ i a , Universidad de Puerto Rico, Rio Piedras , Puerto Rico, 00931. 1967, Thornton 1967). In addi t ion there have been a l a rge number of s tud ies t r e a t i n g the d i s t r i b u t i o n and va r i a t ion of s p e c i f i c groups of organisms on i s l a n d s and the r o l e of h i s t o r i c a l f a c t o r s upon such pa t t e rns . W i t h this broadening base of t h e o r e t i c a l background and accumulation of information on s p e c i f i c a spec t s , t he f i r s t two authors f e l t it opportune t o car ry o u t a comprehensive study of an archipelago conta.ining many i s l ands with a v a r i e t y of s i z e s , in t e r - i s l and d is tances , topography, vegetat ion, time of separa t ion , use by humans, and o the r c h a r a c t e r i s t i c s , and t o s tudy a s many aspects of the biogeography of a s wide a range of organisms a s f eas ib le . Our aim was t o look a t the sub jec t a s a whole and thereby contr ibute toward a syn the t i c understanding of the broad aspects of t h e problem. The o r i g i n a l design of t h e p r o j e c t was presented i n an e a r l y paper (Levins and Heatwole 1963) and some of the da ta have been used i n general reviews (Levins 1968, 1969, Heatwole 1976a). This paper p resen t s the geography, vegetat ion, and ecologica l c h a r a c t e r i s t i c s of the Puerto Rican Bank and c o n s t i t u t e s a background f o r t h e r e s t of t h e s e r i e s (some of which have already been published, e . g. Heatwole and Levins 1972b, 1973, Levins and Heatwole 1973, Levins et a l . 1973), and f o r papers by a v a r i e t y of s p e c i a l i s t s using t h e mater ia l we c o l l e c t e d during our study. GENERAL DESCRIPTION OF THE REGION AND ITS CLIMATE The a rea studied c o n s i s t s of a l l t he i s l a n d s and cays i n the p a r t of t h e Ant i l lean chain making up t h e p o l i t i c a l u n i t s of Puerto Rico, t h e American Virgin Is lands , and the B r i t i s h Virgin Is lands , sometimes re fe r red t o a s "Greater Puerto Rico'' (Thomas and Schwartz 1966) . This includes a l l land masses between l a t i t u d e s 17O 40' N and 18O 45' N and s t r e t c h i n g from the i s l a n d of Monito ( longitude 67O 57' W ) t o Anegada ( longitude 64O 16' W ) . There are 243 i s l ands and cays i n t h i s a rea (not including those emergent ones p e r i o d i c a l l y washed over by t i d e s and lacking t e r r e s t r i a l vegeta t ion) . Of these we surveyed 141, including a l l of the l a r g e r ones. Figure 1 shows a map of the general region and appendix I provides d e t a i l e d ones of se lec ted a reas containing the small cays which were studied. Where poss ib le we followed t h e o f f i c i a l names f o r i s l ands a s l i s t e d by the U.S. Department of Commerce, Coast and Geodetic Survey (1962). When no o f f i c i a l name could be found, we used names supplied by l o c a l fishermen. In cases of nomenclatural d isputes among l o c a l a u t h o r i t i e s , we simply chose one of the a l t e r n a t i v e s . Sometimes we were unable t o obta in any name a t a l l and have named i s l ands ourselves. The cl imate of t h e a rea i s t r o p i c a l and s l i g h t l y modified by a l t i t u d e on t h e l a r g e r i s l ands . Rainfa l l on Puerto Rico i s geographical ly va r i ab le , g r e a t e r i n the c e n t r a l mountains than on the coas ta l p la in . In addi t ion , the re is a general east-west d i f f e rence . On t h e Luquillo Mountains a t t h e northeastern t i p of the i s l a n d , r a i n f a l l may exceed 5,080 mm (200 inches) annually; the southwestern lowlands receive l e s s than 750 mm (30 inches) annually (Pic6 1954 and see Fig. 2 ) . The p r i n c i p a l Virgin I s l ands a re s i m i l a r i n r a i n f a l l t o t h e c o a s t a l a r e a s o f Puerto Rico; sma l l e r , o r more i s o l a t e d i s l a n d s represented by Culebra, Vieques, and Mona i n f i g u r e 2, a r e more x e r i c . Mona is d r i e r than i t s r a i n f a l l would sugges t , a s i t i s honeycombed with limestone caverns which r ap id ly d ra in o f f su r face water. Temperatures a re remarkably uniform seasona l ly and from year t o year i n a given l o c a l i t y (Figs. 3, 4) . However, on Puerto Rico, temperature follows eas t-wes t and a l t i t u d i n a l t rends . Guineo Reservoir ( e l eva t ion 1,000 m) has lower temperatures than Rio P ied ras ( e l eva t ion 15 m) on the no r theas t e rn coas t . Rio P ied ras i s i n tu rn cooler t han Magueyes I s l a n d (10 m) which is rep resen ta t ive of t h e southwestern c o a s t (Fig. 4) . The isotherm f o r mean annual temperatures o f 24O C sepa ra t e s the c o a s t a l p l a i n and some v a l l e y s (below 150 m e l eva t ion and where mean annual values exceeding 26O may occur) from t h e mountains where mean annual va lues below 20? C a r e encountered i n t h e h ighes t p a r t s ; t h e h ighes t temperature eve r recorded f o r t h e i s l a n d was 39.5O C, the lowest 5O C (Pic6 1954). The h o t t e r c o a s t a l a r eas of southwest Puerto Rico have temperatures s i m i l a r t o thosf of the p r i n c i p a l Virgin I s l a n d s (Fig. 4 ) . Very few meteorological d a t a a r e a v a i l a b l e f o r smal l cays , though it can be s a i d t h a t most a r e warm and dry. Figure 3 p r e s e n t s d a t a f o r Magueyes I s l and . However, t h i s i s l a n d i s so c l o s e t o Puer to Rico t h a t it is r e p r e s e n t a t i v e of condi t ions of c o a s t a l southwest Puer to Rico r a t h e r than t h a t of more i s o l a t e d i s l ands . Table 1 gives t h e average condi t ions on Cayo Ahogado, a smal l , nea r ly bar ren sandy cay about 1 km e a s t o f Puer to Rico, during seve ra l days i n March, 1966. F igures 5-7 show t h e d e t a i l s of the d a i l y regimen f o r t h e two most extreme days, March 10 which was b r i g h t and sunny, and March 19 which was heav i ly ove rcas t with occasional f i n e r a i n . The h o t t e s t environment on the cay was t h e s o i l su r face where midday temperatures exceeded 38O C. A t 1 cm and 5 cm below t h e s o i l su r face , temperatures decreased somewhat b u t even t h e r e reached 30? C o r above on h o t days. A i r temperatures nea r t h e ground reached 32O C on warm days, temperature decreased with h e i g h t above ground. However, except f o r a few f l y i n g forms which experience above-ground temperatures , most i n h a b i t a n t s o f smal l cays a r e exposed t o the thermal condi t ions near t h e ground. The low vegeta t ion on Cayo Ahogado ameliorates temperatures somewhat (Fig. 71, although on h o t days a i r temperatures near t h e su r face of small clumps of p l a n t s reach 32 - 33O C. Surface temperatures of leaves were s e v e r a l degrees lower, presumably because of t r a n s p i r a t i o n . Temperature 1 cm down i n t h e s o i l was a s much a s 2O C cooler under vegeta t ion than i n the open. A t 5 cm depth the d i f f e rence was a s much a s 4O C. Although the p l a n t s were small and s p a r s e l y d i s t r i b u t e d , and hence d i d n o t g r e a t l y a f f e c t environmental temperatures , t h e few degrees o f d i f f e r e n c e they caused were i n a range t h a t may reduce t h e i n s o l a t i o n d i r e c t l y reaching small animals. The e f f e c t o f unobstructed r a d i a n t energy can be seen from t h e h igh black bu lb (TBB) temperatures (Fig. 5 ) . The nea r ly ba re , rocky cays probably have even more extreme condi t ions than Cayo Ahogado, more heav i ly vegetated ones a r e probably more moderate. The prevai l ing winds a re from the nor theas t and apparently have been so a t l e a s t back i n t o the Pleistocene (Kaye 1959). Marine currents a re e a s t t o west, although a northward current e x i s t s between Mona and Puerto Rico, and there i s a northward def lec t ion between Vieques and Puerto Rico (Kaye 1959). Hurricanes usually t r ave l i n a general e a s t t o west d i rect ion. VEGETATION The Puerto Rican and Virgin Is land f l o r a has been most recent ly summarized by Bri t ton and Wilson (1923-30) and by L i t t l e and Wadsworth (1964). Ecological treatments of a broad nature have been presented by Gleason and Cook (1927) , Cook and Gleason (1928) and Dansereau (1966). Only a few a r t i c l e s have d e a l t with the p lan t s on the small i s lands (e.g. Br i t ton 1924, 1933 on Hicacos and Culebra, Heatwole et a l . 1963 on Cayo Santiago and Cayo Batata, and D'Arcy 1971, 1975 on Anegada) . Our records a re presented i n Appendix 11. Analysis of the vegetat ion of the i s l ands t rea ted here would be a major p ro jec t i n i t s e l f and was not possible within the scope of the present invest igat ion. However, broad vegetation types could be recognized and were grouped on a physiognomic ba s i s i n t o 12 categories, most of which include more than one associa t ion, o r a t l e a s t varied somewhat i n f l o r i s t i c composition from place t o place. The c l a s s i f i c a t i o n i s not intended t o be phytosociological, but r a the r a useful descr ip t ion of t he type and d ive r s i t y of avai lable s t r u c t u r a l hab i t a t s f o r animals. The s p a t i a l re la t ionships of the categories t o one another and t o several major environmental parameters a re c l a r i f i e d i n Figs. 8 and 9. The categories are as follows: 1. Lack of Vegetation. Extensive areas of bare rock o r sand, usually coas ta l , though occurring loca l ly f u r t he r inland. 2. Succulent Beach Vegetation. Often nearly pure stands of low, succulent , halophytic herbs. Sesuvium portulacastrum and Phi loxer is vermicularis, usually under 30 cm i n height , occur alone o r i n combination on r e l a t i v e l y undisturbed gravelly or sandy beaches1. These two species p lus Bat is maritima and Sal icornia perennis form various combinations a f t e r the elimination of mangrove (81, o r i n otherwise intermittently-flooded, shallow, s a l i ne coasta l depressions. Bat is may reach 70 cm i n height. 3. Mixed Beach Vegetation. A var iable mixture of herbs (Cakile lanceola ta) , small suff ru tescents (~upho rb i a buxifol ia) , rhizomaceous Nomenclature follows Bri t ton and Wilson (1923-30) . gras ses ( S p o r o b d u s v i r g i n i c u s , S p a r t i n a p a t e n s ) and creeping v ines (Ipomoea pes -caprae , Canava l ia mari t i m a , V igna mar ina ) , sometimes wi th Sesuv ium p o r t u l a c a s t r u m . Vegetation usua l ly l e s s than 1 m t a l l , with low cover. On sand, g r a v e l , o r c r ev ices i n c o a s t a l s h e l f l imestone, f a i r l y r e s i s t a n t t o d is turbance , and recovers r ap id ly . 4. Beach Shrubs. Small, s c a t t e r e d shrubs intermixed with he rbs and g r a s s e s , occas iona l ly conta in ing a h igh propor t ion of v ines which form a n e a r l y continuous mat. Height u sua l ly 1-2 m, found in l and from the previous type. Common spec ies a r e S u r i a n a mari t i m a , T o u r n e f o r t i a gnapha lodes , and T h e s p e s i a popu lnea , with the spec i e s c h a r a c t e r i s t i c of t h e previous type ( 3 ) a s ground cover. F a i r l y r e s i s t a n t t o d is turbance . 5. Graminoid. Stands havTng the graminoid l i f e form dominant, whether composed of t r u e g ra s ses o r of sedges. Usually a l s o conta ins a number of forbs . Usual ly 1 m o r l e s s h igh , though t a l l e r s t ands a r e sometimes found. Found i n t he i n t e r i o r of in te rmedia te -s ized and l a r g e r i s l a n d s . Always a discl imax o r success iona l s t a g e i n the c l i m a t i c zone s tud ied (Richards 19571, maintained by graz ing , f i r e , o r p e r i o d i c c u t t i n g o r mowing. Various graminoid spec ies cover t h e f u l l range of moisture and edaphic condi t ions found i n the s tudy region. 6. Scrub. Shrubs of va r ious types , c a c t u s , and v i n e s , f r equen t ly intermixed with herbs and g ra s ses . Varies from l e s s than 50% t o 100% cover , e a s i l y pene t rab le t o impenetrable , and l e s s than 1 m t o over 2 m, occas iona l ly higher . Frequent dominants a r e Croton a s t r o i t e s , C . r i g i d u s (both rep laced by C . d i s c o l o r i n Anegada) , Lantana i n v o l u c r a t a , An t h a c a n t h u s s p i n o s u s , and P i t h e c e l l o b i u m ungu i s c a t i . A discl imax maintained by overgrazing and overbrowsing, p r imar i ly by f e r a l goa t s , i n the i n t e r i o r of in te rmedia te -s ized , d r i e r i s l a n d s and on t h e leeward (rain-shadow) s i d e s of t h e l a r g e s t i s l ands . Shrub s t a g e s i n t h e zone where moist f o r e s t (10) i s climax a r e success iona l and c o n s i s t c f more mesomorphic spec i e s , o f t e n seed l ings and sap l ings of l a r g e r , secondary f o r e s t t r e e s . 7. Coastal Groves. Stands of small t r e e s o r shrubs , i n l and from ( 4 ) , ranging from n e a r l y p r o s t r a t e and l e s s than 1 m i n h e i g h t on windswept c o a s t s and dunes, t o 4 m o r more i n p ro t ec t ed s i t e s . Usually provide dense shade with a heavy accumulation of l e a f l i t t e r . Frequent ly pu re s t ands of Coccoloba u v i f e r a o r Hippomane m a n c i n e l l a , o r mixtures of s e v e r a l t o many spec i e s ; Elaeodendron xy locarpum, ~ r i t h a l i s f r u t i c o s a , Conocarpus e r e c t a , and t h e t r ee -cac tus Opunt ia r u b e s c e n s a r e prominent. 8. Mangroves. Stands of mangrove ranging from s c a t t e r e d s a p l i n g s about 1 m i n h e i g h t t o f o r e s t s over 10 m, p rovid ing r a t h e r deep shade, i n permanently- o r i n t e rmi t t en t ly - f looded depress ions behind c o a s t s , and along c o a s t s and on o l d r e e f s e t c . which a r e s h e l t e r e d from wave ac t ion . R h i zophora mangle , A v i c e n n i a n i t i d a , Laguncu lar ia racemosa and Conocarpus e r e c t a , e i t h e r a s s ing le - spec i e s s t ands o r i n va r ious combinations. 9. Xeric Forest. Deciduous, open fo re s t , frequently with sparse understory of cactus, thorny shrubs, vines, and annual grasses. Height usually over 8 m. I n t e r io r of intermediate-sized is lands and le~eward (rain-shadow) s ides of l a rges t islands. May be absent on the windward (humid) s ides of the l a t t e r , where mesic fo res t (10) l i e s adjacent t o coastal formations, except where loca l edaphic-topographic conditions permit xer ic fo res t . Probably includes Dansereau' s (1966) category of Semi-deciduous Forest and L i t t l e and Wadsworth's (1964) Dry Coastal and Dry Limestone fores t s . Dominant t rees variable from place t o place; P i s o n i a s u b c o r d a t a , T o r r u b i a f r a g r a n s , B u r s e r a s imarouba, C i t h a r e x y l u m f r u t i c o s u m , Tabebu ia h e t e r o p h y l l a , and the giant cactus C e p h a l o c e r e u s r o y e n i are representative. 10. Mesic Forest. Includes a var ie ty of moister, a l t i tud ina l ly - zoned types including those cal led Moist-coastal, Moist Limestone, Lower and Upper Cordi l lera , and Lower and Upper Luquillo Forest by L i t t l e and Wadsworth (19641, and Lowland Rain Forest, Lower Montane Rain Forest , Montane Forest and Montane Scrub by Dansereau (1966). Physiognomy and f l o r i s t i c s are variable (see Beard 1944, Richards 1957). Such a var ie ty is included under one heading since i n the region studied, these fo re s t s occur only on the l a rges t i s lands , some types only on Puerto Rico. Finer d i s t inc t ions would be unnecessary for our purposes . 11. Coconut Groves. Usually planted by man i n f l a t , sandy coasta l areas. Light shade, understory usually composed of species of the mixed beach vegetation (3) and variable. 1 2 . Other. Any vegetation not f i t t i n g any of the above categories, e.g. crops, ruderals, dooryards, o r vegetation of other highly modified areas. During the survey of a par t i cu la r is land, the vegetation types were recorded, and where feasible , the percentage of the is land covered by each one estimated and a rough sketch-map drawn. When only a few individual p lan ts were present on an is land, complete censuses were made. In some instances, vegetational reconnaissances were made. The r e su l t s are presented i n Table 2. By way of summary it can be s t a t ed t h a t Puerto Rico contains a l l the vegetation types outl ined (1 - 2 Culebra and Vieques have xer ic t o mesic fo res t s (9, 10) ; Mona, Caja de Muertos and Desecheo support xer ic fo re s t , a l l f ive have a var ie ty of the simplest types (1 - 8 ) . Monito has predominantly scrub ( 6 ) . The small cays near the southern and southwestern coast of Puerto Rico are mostly mangrove is lands (8) ; those fur ther offshore tend t o be sandy and nearly bare (1) o r w i t h succulents ( 2 ) mixed beach vegetation (31, o r beach shrubs ( 4 ) . The group of cays extending toward Culebra from northeastern Puerto Rico are mostly steep-sided, limestone o r cemented sand dunes, although a few low sandy islands a lso occur. Most support scrub (61, /----- succulent o r mixed beach vegetation ( 2 , 3 ) , although the larger ones have shrubs (4) and occasionally t rees . The cays south of t h i s chain ( ea s t of Puerto Rico) and around Culebra Island are variable, most being e i t h e r rocky with a beach, o r sandy. The larger ones support xer ic fo re s t (91, the smaller ones only succulent o r mixed beach vegetation (2,3) o r scrub ( 6 ) . The Virgin Islands, St . John, Tortola and St. Croix have mesic fo re s t plus a l l other categories (1 - 1 2 ) . The other pr incipal islands except Anegada, as well as a few somewhat smaller ones such as Guana, Greater Caminoe, Peter, Norman, and Greater Thatch have xer ic fores t . The remaining cays and small islands plus Anegada are variable. However, few support vegetation more lush than scrub (61, o r a t most limited areas of xer ic fo re s t (9) . The available climate and s o i l data , corroborated by conversation with older inhabitants, indicate t h a t a t one time fo re s t was more extensive on both the larger and the smaller islands. Apparently it has been decimated by charcoal burners, cu l t iva tors , and f e r a l animals, a widespread phenomenon throughout the Caribbean as indeed i n the t ropics generally. GEOLOGY Rosen (1975) has reviewed t h e previous his tory of the Caribbean. Although there i s not unanimity among au thor i t i es on the topic , he f e l t t h a t the most reasonable synthesis of the geologic and biogeographic data was the following sequence of events. I n the l a t e Mesozoic when South America was separating from Africa, a subduction zone consuming the eastern Pacif ic sea f loor bordered the western coast of both North and South America and the area between them, the l a t t e r consist ing of a volcanic archipelago, the Proto-Antilles. Subsequently, separate North and South American p la tes arose by the formation of two decoupling f a u l t s on e i t he r side of the Proto-Antilles. With the continued r e l a t i ve westward d r i f t of the North American and South American p la tes , the Proto-Antillean region became displaced eastward towards i t s present r e l a t i ve posit ion; a new f a u l t zone occurred which separated the Proto-Antilles i n to two subregions which subsequently became the Greater Ant i l les and Lesser Ant i l les . With the continued westward movement of the major American continents, fur ther fau l t ing occurred breaking up the Central American region in to an archipelago which subsequently joined t o form the present day isthmus; the Caribbean is lands aligned themselves in to t h e i r present re la t ive posit ions. I f t h i s model i s correct , the Greater Ant i l les have been an archipelago for a long time, contrary t o previous opinion t h a t the major Antillean islands were broadly connected (Schuchert 1935). Connections between adjacent banks were ra re , the Puerto Rican one never having been connected t o the nearest one t o the e a s t (St. Maarten) (But ter l in 1956). I f it was ever connected to Hispaniola, it l o s t the connection i n the Pliocene or e a r l i e r itchel ell 1954) . The Puerto Rican Bank (Puerto Rico., i t s out ly ing i s l ands , the American and B r i t i s h Virgin Is lands) r e s u l t e d from vulcanizat ion i n the Cretaceous (Meyerhoff 1933) and became emergent during orogenic movements i n the l a t e Eocene (But t e r l in 1956). In con t ras t t o t h e paucity of connections between banks, connections of i s l a n d s within the Puerto Rican Bank have been extensive and recent . Heatwole and MacKenzie (1967) have shown t h a t t h e p r i n c i p a l i s l ands of the Virgin group (except S t . Croix) l o s t t h e i r connection with each o the r and with Puerto Rico only about 8,000-10,000 years ago, due t o e u s t a t i c r i s e i n sea l eve l . Culebra l o s t i t s connection w i t h Puerto Rico and the Virgins a t the same time, although Vieques, Caja de Muertos, and many small cays remained connected t o Puerto Rico u n t i l about 6,000 years ago. The smaller i s l ands around the p r i n c i p a l Virgins were separated from the l a t t e r a t various times before 8,000-10,000 B.P. By c o n t r a s t , Mona, Monito, Desecheo and St . Croix h a w been i s o l a t e d much longer, no t having been connected t o any o the r i s l a n d s s ince a t l e a s t t h e Pliocene, i f then. A number of i s l a n d s were p resen t a t various times which have s ince submerged. ISLAND AND COASTLINE FORMS The l a r g e r i s l a n d s a re of volcanic o r i g i n and c o n s i s t mainly of igneous and metamorphic rock with q u i t e s t eep topography. Puerto Rico has , i n add i t ion , an extensive northern and a smaller southern s t r i p of cenozoic limestone which has been extens ively eroded, giving r i s e t o c h a r a c t e r i s t i c low, blocky, ve r t i ca l - s ided h i l l s w i t h many caves. Mona, Monito and t h e higher i s l ands to t h e nor theas t of Puerto Rico a r e of s i m i l a r o r i g i n , while Anegada i s a low, f l a t limestone s h e l f , con t ras t ing markedly w i t h a l l t he o the r i s l a n d s of the Puerto Rican bank save f o r a few small cays. Form of t h e smaller i s l a n d s va r i e s considerably, and ranges from low, sandy cays w i t h gent ly s loping beaches t o mushroom-shaped ones surrounded by v e r t i c a l c l i f f s undercut a t the base by wave ac t ion . Many i s l a n d s have a g r e a t proport ion of the c o a s t l i n e made up of rock which i s n e i t h e r v e r t i c a l c l i f f , nor beach. We termed t h i s " intermediate type". A f i n a l coas t l ine type consisted of mangrove swamp. Most l a rge i s l a n d s have severa l c o a s t l i n e types, inc luding beach, undercut c l i f f s , and intermediate type. METHOD OF SURVEY Each i s l a n d surveyed was described a s t o i t s vegetat ion (see above), geological type, s o i l , presence o r absence of standing water, maximum height , a rea , na ture of shore l ine , and proport ion of each type of coas t , proport ion surrounded by b a r r i e r r e e f , d is tance t o nea res t o ther land- mass on t h e Puerto Rican she l f i n each of 4 quadrants , degree of disturbance by humans and time of i s o l a t i o n from o the r land masses. Proport ions of various shore l ine types were obtained by measuring the perimeter on a map o r a e r i a l photograph with a Radix map measurer, keeping values f o r each coas t l ine type separa te i n accordance with observations made while on the i s land. Percentages of each type were then ca lcula ted . I s l a n d a reas were obtained e i t h e r from the l i t e r a t u r e , from maps using a planimeter , o r by d i r e c t measurement. Maximum h e i g h t was obtained from topographic maps, o r i n the case of small cays by d i r e c t est imation o r measurement. The o the r information was obtained by d i r e c t observation supplemented by maps, a e r i a l photographs, n a u t i c a l c h a r t s , conversaticns with inhab i t an t s of various i s l ands , and t h e l i t e r a t u r e . On every i s l a n d v i s i t e d , each of the above-defined vegetat ion ca tegor ies which was p resen t was searched f o r the following group of animals; t e r r e s t r i a l isopods, centipedes, mi l l ipedes , pseudoscorpions, amblypigids (= phrynichids o r t a i l l e s s whip scorpions) , scorpions, sp ide r s , a n t s , Drosophila, land s n a i l s , amphibians and r e p t i l e s ; o the r groups provided supplementary information on c e r t a i n aspects . We were oppor tun i s t i c i n t h a t ease of sampling and t h e p robab i l i ty of obtaining adequate samples i n a r e l a t i v e l y s h o r t time was a considerat ion i n our choice of groups. However, the animal groups we used were chosen t o include both eurytopic and s tenotopic forms, those with weak and those with s t rong d i s p e r s a l powers, and groups with a wide range of suspected evolut ionary r a t e s . S p e c i a l i s t s i n various groups i d e n t i f i e d ( o r a re i n the process of iden t i fy ing) our mater ia l and advised on techniques which would provide a s complete a representa t ion of an i s l a n d ' s fauna a s poss ib le . These methods included use of (1) Tullgren funnel ex t rac t ion of l i t t e r samples t ranspor ted t o the labora tory i n p l a s t i c bags, (2) sweeping vegetat ion with an i n s e c t n e t , (3) beat ing vegetat ion over a white shee t , ( 4 ) examining l i t t e r on a white shee t , (5) s e t t i n g ou t b a i t (mixed f r u i t s f o r Drosophila, sugar and tuna f o r a n t s , e t c . ) , (6) shooting o r noosing ( r e p t i l e s ) , ( 7 ) ca re fu l search of the surface of t h e ground and vegetat ion and under rocks and o the r o b j e c t s , and (8) breaking open twigs, o ld t e rmi te n e s t s , logs , and o t h e r debr i s . A l l da ta were s to red on computer cards. S t a t i s t i c a l t reatment is discussed l a t e r i n appropriate papers, a s a r e o t h e r s p e c i a l methods used f o r individual p a r t s of t h e p ro jec t . Biogeographic and taxonomic treatments w i l l be published by the various s p e c i a l i s t s t h a t have received mater ia l . The appendices l i s t the r e s u l t s f o r some groups f o r which a number of i d e n t i f i c a t i o n s a re now avai lable . SPECIAL NOTES The i s l a n d of S a i l Rock (Appendix I ) requi res s p e c i a l mention. I t i s a mass of rock r i s i n g 38 m (125 f t ) p rec ip i tous ly o u t of t h e sea. I t i s about 100 m i n diameter. The c l i f f s around it a re v e r t i c a l o r near ly v e r t i c a l and a r e undercut a t the base. I t is unusual i n t h a t it completely lacks t e r r e s t r i a l vascular plants and hence no local autotrophic energy base for the surprisingly large number of t e r r e s t r i a l animals. Indeed, the only t e r r e s t r i a l plants observed a t a l l was a green alga in one crevice on the north side. A few individuals of a marine plants , Sargassum, collected by sea birds o r material was present but did not appear t o have any t e r r e s t r i a l animals associated with it or feeding upon it. We v i s i t ed the is land i n May 1966, scaled the c l i f f s and made an intensive search for organisms on the top. Numerous cracks and crevices occur i n the rock on top, and on the few f l a t , or nearly f l a t areas, there are some loose boulders and stones. From these places we collected species of t e r r e s t r i a l vertebrates and one vertebrate (a gekkonid l i za rd , Sphaerodactylus macrolepis macrolepis); many of t he species were qui te abundant. By f a r the most abundant arthropod present was a t e r r e s t r i a l isopod. I t occurred i n surprisingly dense populations and probably served as the basis fo r much of the r e s t of the t e r r e s t r i a l food chain which consisted largely of predators, there was 1 species each of centipede, t a i l l e s s whip scorpion (amblypigid = phrynichid) , scorpion and spider. There was in addition one species of ant , several other species of insects , and a land crab. Unfortunately none of the invertebrates were iden t i f ied t o species as our collection was l o s t in the mail when sent t o spec i a l i s t s for ident i f icat ion and we have not had opportunity to v i s i t the is land again. However, su f f i c i en t i s known about the genuine feeding habi ts of some of t he groups to comment on the probable trophic re la t ions . The top of the is land was used extensively by sea birds for nesting and t h e i r excrement l i t e r a l l y covers the is land, giving it a white-washed appearance. These birds feed on f i s h and hence it i s probable t h a t they serve as t ransfer organisms (Heatwole 1975) obtaining energy from the marine community and depositing a food source for t he t e r r e s t r i a l community on the is land in the form of guano and on occasions as carrion (dead adults o r chicks) o r broken eggs. The guano is believed t o be the most important source as i s carrion was observed and the only species l ike ly t o be scavengers t h a t were present was the land crab and possibly the ant. The undercut nature of the is land and i t s height would make work up of marine carrion unlikely. Isopods generally feed on de t r i t u s o r other f inely divided organic matter and we suspect t h a t it fed on guano and in turn was preyed upon by the predatory invertebrates. The larger predators such as scorpion, whip scorpion, and l iza rds probably e a t isopods and some of the invertebrates t h a t prey on isopods. None of the l i za rds we collected had prey i n t h e i r stomachs. However, we did obtain three recognizable items from the section of one animal. There were remains of an ant , the head of an insect larva, and surprisingly, par t s of a species not otherwise known from the is land, a homopteran. The l a s t is a plant feeder and must represent a waif arr iving ae r i a l l y (the nearest vegetated land mass, Culebra Island is 14 km away). In summary, the probable trophic re la t ions are (1) a t ransfe r of marine-derived energy v i a sea birds i n the form of guano and carrion, ( 2 ) i t s u t i l i z a t i on by isopods which (3) serve a s prey fo r a var ie ty of predators, ( 4 ) leading t o secondary predators. The endogenous prey i s probably supplemented by (5) a e r i a l waifs. Complete dependence of an insular t e r r e s t r i a l community upon exogenous, marine- derived energy, although unusual, is not unique. Heatwole (1975) reports communities of several t e r r e s t r i a l species (including predators) on vegetation-free sand cays i n the Coral Sea. The source of the t e r r e s t r i a l fauna on S a i l Rock i s problematic. S a i l Rock became i so la ted from the once continuous land mass of Greater Puerto Rico (about 8,000 years B.P.) (Heatwole and MacKenzie 1967), and it seems unlikely t h a t the res ident species could have maintained themselves on such a small barren island. On the whole the undercut nature of t he i s l and ' s base would suggest t h a t a t present flotsam transport would be unlikely and the f l i gh t l e s s nature of many of the res ident species would mi l i t a te against a e r i a l transport . The d i f f i c u l t y of access to the is land would make human transport unlikely, although there is an automatic l i g h t house on top which i s per iodical ly serviced. Introduction of so many species by t h i s means, however, seems unlikely. From the above, it i s c lear t h a t S a i l Rock i s especial ly in te res t ing from the standpoints of is land biogeography and community ecology. I t would warrant quant i ta t ive study by someone i n a posit ion t o carry ou t a long-term observation there. DISCUSSION The br ie f description of the general ecology of t he archipelago presented above provides a summary of loca l conditions during the 8-year period i n which data were collected. Many ecological charac te r i s t i cs are , however, i n the process of rapid change, largely through human influence. An assessment of the nature of such changes i s requis i te fo r placing the present study in perspective and for evaluation of future data. In pre-Columbian times a succession of cultures occurred i n the area, especial ly on the la rger islands. However, even those a s small a s Culebra (about 1 4 x 6 kms) had a t l e a s t semi-resident populations, a midden containing various a r t i f a c t s was found on t h i s is land during one of our f i e l d t r i p s . Some species, such a s useful plants and the edible iguana, may possibly owe t h e i r d i s t r ibu t ion i n pa r t t o transport by these ear ly residents. In post-Columbian times, man's e f f e c t was accelerated through addit ional c lear ing of land and establishment of an European-type cul ture . Domestic animals and a var ie ty of ornamental and edible plants were purposefully introduced a s well a s various weeds, rodents, insec t s and other involuntari ly- transported species. Feral ca t s and especial ly r a t s have possibly had an adverse e f f e c t on the now rare and endangered Puerto Rican parrot (Amazona v. v i t t a t a ) through depredation of nes t s (Rodriguez- Vidal 1959). The mongoose was introduced i n order t o control rodents (unsuccessfully) . The ro l e of t he mongoose i n the decline and ext inct ion of West Indian native fauna may not be a s g rea t a s i s sometimes a t t r i bu t ed t o it, but it is almost ce r ta in ly responsible f o r l oca l ext inct ion of some l i z a rd s , snakes and ground-nesting b i rd s (see Barbour 1930, Heatwole and Torres 1967, Phil ibosian and Ruibal 1971). The cane toad (Bufo marinus) was brought t o Puerto Rico t o control i n sec t pe s t s of sugar cane i n 1920 ( B a r t l e t t 1949) and i s now abundant on various is lands . Cayo Santiago has had a f e r a l band of rhesus monkeys f o r a number of years. Recently, introduction of some of them i n t o several addi t ional i s l ands was made. These populations w i l l undoubtedly have an ecological e f f ec t . Goats and sheep a r e perhaps the most des t ruct ive of any introduced species, and there are probably few is lands i n the archipelago which have no t been disturbed t o some extent by these animals a t some time o r o ther . The ea r ly custom of releasing goats and other domestic ungulates on small i s l ands and cays f o r l a t e r use by mariners was apparently common (Davis 1971). Mona and Desecheo Islands s t i l l maintain l oca l populations or ig inat ing i n t h i s way; the former i s l and serves as a reserve f o r sportsmen t o hunt goats and f e r a l pigs. Many of the cays i n the Virgin Islands have goat herds which belong t o res idents from l a rge r i s l ands and from which individuals a re per iodical ly k i l l e d fo r meat. Perhaps the i s l and most af fected by f e r a l animals is S a l t Is land, B . V . I . , i n which the g rea te r p a r t of t he vegetation has been reduced t o a low, open s t rand of Croton r i g idus and C. a s t r o i t e s , species unpalatable even t o goats. Except f o r creeping Opuntia repens, the spaces between Croton bushes are nearly devoid of o ther vegetat ion, and goats have been observed gleaning the t i n y grasses and annuals which do appear. On S a l t Is land a t l e a s t , free-roaming sheep and c a t t l e a l so played a ro le i n decimating once-considerable grassy areas ( M r s . Beatr ice Smith, personal communication). These animals died ou t , s ince they cannot subs i s t on a d i e t of woody d ico t s a s can goats. Observations on exclosures over a three-year period (Byer, i n preparation) suggest t h a t once ground cover i s eliminated, re-establishment of woody p lan t s i s retarded even i n the absence of goats. Possibly increased run-off e i t he r washes seeds away d i r e c t l y o r removes organic matter necessary fo r t h e i r germination. The degree of disturbance t o a small i s l and seems t o be r e l a t ed t o i t s geomorphologic type. Monito, which has s teep s ides undercut a t the base, i s r e l a t i ve ly inaccessible and has probably been v i s i t e d by humans only a few times (Rolle e t a l . 1964). The same i s t rue of a number of the small i s lands i n the chain j u s t nor theas t of Puerto Rico. The l a t t e r , however, were used f o r s t r a f i ng p rac t i ce during World War I1 and remnants of s h e l l s can s t i l l be found embedded i n rock on the top of some. Others of the r e l a t i ve ly inaccess ible steep-sided i s l ands (e. g. S a i l Rock) cons t i tu te shipping dangers and have l i gh t - houses o r o t h e r navigat ional a ids which must be p e r i o d i c a l l y serviced. Many of t h e small access ib le i s l ands a r e f requent ly v i s i t e d f o r s h o r t per iods by fishermen who camp on the beach bu t otherwise have a minimal e f f e c t . Some i s l ands containing l a r g e colonies of nes t ing sea b i r d s a r e pe r iod ica l ly v i s i t e d by egg ga the re r s (e.g. Frenchcap Cay). A number of t h e more access ib le i s l ands have people l i v i n g on t h e m , even some a s small a s Ramos Is land (< % k m i n g r e a t e s t diameter) . Lobos I s l and ( s l i g h t l y more than % km i n g r e a t e s t diameter) has a t o u r i s t h o t e l , and I s l e t a Marine serves a s a yacht basin. Most i s l a n d s with some beach and l a r g e r than 1 km i n g r e a t e s t diameter a r e inhabi ted e i t h e r permanently o r seasonally. Some inhabited i s l a n d s show almost no disturbance by their res iden t s (e.9. Guana I s l and) ; most however, a re c l e a r l y modified by a g r i c u l t u r a l o r o t h e r p rac t i ces . Cayo Luis Peiia and p a r t of Culebra I s l and a r e used f o r bombing and naval gunnery p rac t i ce . During World War 11, Desecheo was used f o r bombing p r a c t i c e and bomb fragments can s t i l l be found on various p a r t s of t h e i s l and . Human e f f e c t s have accelera ted g r e a t l y during our study. On many small uninhabited i s l ands i n the beginning of the study one was reminded of the proximity of human populat ions only by the la rge numbers of b o t t l e s , l i g h t bulbs, shoes, e t c . encountered i n the beach d r i f t . Most, however, e spec ia l ly i f cu r ren t ly goat-free, appeared i n a r e l a t i v e l y na tu ra l s t a t e . Various such i s l a n d s c lose t o Puerto Rico, were se lec ted f o r d e t a i l e d , long-term study (e.9. Cayo Ahogado and Palominitos) . I t was fo r tuna te t h a t our s tudy was i n i t i a t e d a s e a r l y a s it was because today one would have t o s e l e c t l e s s access ib le i s l a n d s i n order t o car ry ou t such s tudies . Those near Puerto Rico with good anchorage f o r small c r a f t a r e now v i s i t e d by l a rge numbers of weekend excurs ion i s t s , who have turned t h e cays i n t o v e r i t a b l e garbage and t r a s h dumps and have c u t woody vegetat ion f o r campfires and t e n t supports. I t appears t h a t the small, inhabited i s l a n d s whose owners discourage t r e spass ing a r e l i k e l y t o r e t a i n some s i m i l a r i t y t o t h e i r n a t u r a l s t a t e , whereas uninhabited, pub l i c ones a r e already being rap id ly destroyed. The l a r g e r i s l ands a l s o show an alarming degree of human dis turbances t o na tu ra l communities. For example, i n a s tudy contrac ted by the Puerto Rican government, Heatwole (1970) found t h a t t h a t i s l a n d had l o s t a mean of 1.7% of i t s coverage of mangrove per decade between 1930 and the mid-1960's. Between 1965 and 1970, l a rge t r a c t s were l o s t , some swamps dying completely. I n d u s t r i a l po l lu t ion and in te r fe rence with drainaqe p a t t e r n s by construct ion a c t i v i t i e s , dredging, and f i l l i n g cont r ibuted t o t h e i r demise. Proposed t o u r i s t i c development i n the Vacia Talega area w i l l probably e l iminate much of Puerto Rico ' s b e s t remaining mangrove, and i s already f looding the i s l a n d ' s l a r g e s t s tand of A v i c e n n i a , near Boguer&, with f r e s h water i n o rde r t o convert it i n t o a Typha marsh t o be used f o r waterfowl hunting. The flooding was undertaken because a l l s i zeab le n a t u r a l fresh-water marshes, once thought v a l u e l e s s , had been e l imina ted some time i n the p a s t by a g r i c u l t u r a l development. The d e s t r u c t i o n of h a b i t a t wi th i nc reas ing l e v e l s of human popula t ion i s of course, n o t a problem unique t o i s l a n d s . However, t h e r e may be unique a s p e c t s a r i s i n g from i n s u l a r i t y . I t would appear t h a t t h r e e major t a s k s f ace i s l a n d e c o l o g i s t s , (1) d e t a i l e d s tudy of the func t ion ing of r e l a t i v e l y undisturbed i n s u l a r ecosystems while such a r e s t i l l a v a i l a b l e , (2) t h e assessment of t he e f f e c t of human p re s su re on such ecosystems, and (3) recommending p r a c t i c e s f o r use of small i s l a n d s i n ways t h a t w i l l n o t r e s u l t i n t h e i r d e s t r u c t i o n and l o s s t o the human populat ion. The s e r i e s , t o which t h i s paper r e p r e s e n t s t h e in t roduc t ion , concen t r a t e s l a r g e l y on t h e f i r s t of t h e s e t a s k s . ACKNOWLEDGEMENTS We a r e g r a t e f u l t o t h e c i t i z e n s of t h e United S t a t e s of America who f inanced t h i s p r o j e c t through a Nat ional Science Foundation g r a n t (GB-2906). D r . Maxim Cerame-Vivas a ided by p u t t i n g t h e Marine Research Vessel , Medusa, a t ou r d isposa l . The success of t h e p r o j e c t was g r e a t l y enhanced by t h e ded ica t ion of t h e research a s s i s t a n t s , Faus t ino McKenzie and Frank Torres , whose e f f o r t s f r equen t ly went beyond t h e c a l l of duty. Many s tuden t s and s t a f f o f t h e Un ive r s i t y of Puer to Rico a ided i n t h e f i e l d work. Various people and i n s t i t u t i o n s provided f a c i l i t i e s , lodging, t r a n s p o r t a t i o n and o t h e r e s s e n t i a l a i d dur ing f i e l d expedi t ions . These were Eunice Boardman, Reginald Penn, t h e Po l i ce Department of Cabo Rojo, P.R., t h e U.S. Coast Guard, t he U.S. Navy, t h e I n s t i t u t e o f Marine Biology a t La Parguera, P.R., t h e Department of Agr icu l ture of t h e B r i t i s h Virgin I s l a n d s , t h e Ca tho l i c Univers i ty of Puer to Rico, and t h e l a t e T i t o Wirshing. John Cooper and Steven D. Garber suppl ied t h e i r d i s t r i b u t i o n a l records f o r ou r use. We a r e g r a t e f u l to Frank Torres , Al ice Matta and Angelica M d i z f o r summarizing t h e a rachnid da t e . Roy Woodbury aided i n i d e n t i f i c a t i o n of some of t h e p l an t s . Terence Done, E l i zabe th Cameron and Barbara Saylor Done c r i t i c i z e d t h e manuscript and Viola Watt, Neva Walden, Russe l l Hobbs, Sue Dixon and Audry Heatwole aided i n i t s prepara t ion . LITERATURE: CITED Abbott, I. 1974 Numbers of p l a n t , i n s e c t and l and b i r d s p e c i e s on n ine teen remote i s l a n d s i n t he Southern Hemisphere. B i o l . J. Linn. Soc. 6: 143-152. Baker, H. G. and G.L. S tebbins 1965 T h e g e n e t i c s o f c o l o n i z i n g s p e c i e s . Academic P res s , N e w York. Bassot , J.M. and E.E. B a l l 1972 Bio logica l co lon iza t ion of r e c e n t l y c r e a t e d i s l a n d s i n Lake Wisdom, Long I s l a n d , Papua New Guinea, wi th observa t ions on t h e fauna of t h e lake . Papua New Guinea S c i . Soc . Proc. 23: 26-35. Beard, J.S. 1944 Climax vegetat ion i n t rop ica l America. Eco logy 25: 127-158. Becker, P. 1975 I s l and colonizat ion by carnivorous and herbivorous Coleoptera. J . A n i m . 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Cambridge Univ. P r e s s , Cambridge, 450 pp. Rosen, D.E. 1975 A v i ca r i ance model of Caribbean biogeography. S y s t e m a t i c Zoology 24: 431-464. Sauer , J . D . 1962 E f f e c t s o f r e c e n t t r o p i c a l cyclones on the c o a s t a l vege t a t i on o f Mauri t ius . J o u r . E c o l . 50: 275-290. Schoener, A. 1975 Experimental zoogeography: co lon iza t ion of marine min i - i s lands . Amer. Nat . 108: 715-738. Schuchert , C. 1935 H i s t o r i c a l Geology o f the An t i l l e a n - C a r i b b e a n Reg ion . John Wiley and Sons, N e w York, 811 pp. Schwartz, A. and R. Thomas 1975 A check - l i s t of West Indian amphibians and r e p t i l e s . C a r n e g i e Mus. Nat . H i s t . S p e c i a l Pub1 . 1: 1-216. Sheppard, D.H. , P.H. Klopfer and H. Oelke 1968 Hab i t a t s e l e c t i o n : Di f fe rences i n s t e r eo typy between i n s u l a r and c o n t i n e n t a l b i r d s . Wilson B u l l . 80: 452-457. 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U.S. Gov' t P r i n t i n g O f f i c e , Washinqton, D. C . , 264 pp. p l u s 1965 supplement, 17 pp. Whitehead, D.R. and C.E. Jones 1969 Small i s l a n d s and the equ i l i b r ium theory of i n s u l a r biogeography. E v o l u t i o n 23: 171-179. Williams, E.E. 1969 The ecology of co lon iza t ion a s seen i n t he zoogeography of anol ine l i z a r d s on smal l i s l a n d s . Q u a r t . Rev . B i o l . 44: 345-389. Wilson, E.O. and R.W. Taylor 1967 An es t imate of the p o t e n t i a l evolut ionary increase i n species dens i ty i n the Polynesian a n t fauna. Evolution 21: 1-10. TABLE 1. TEMPERATURES (MEANS AND RANGES) I N DIFFERENT MICRO-HABITATS ON CAY0 AHOGADO, MARCH 16-21, 1966. AIR TEMPERATURES SOIL TEMPERATURES TEMPERATURES AT A CLUMP OF VEGETATION 5 cm i n 1 cm i n S o i l S u r f a c e S u r f a c e of Cen te r o f T~~ 1 cm 15 cm 1 m 5 cm deep 1 cm deep Sur face s o i 1 s o i l under Clump Vegeta t ion Clump DATE Rh % La te even ing and n i g h t on ly . ** E a r l y morning on ly . Table 2. Vegetation types p resen t on the i s l ands of the Puerto Rican Bank. X i nd ica tes presence b u t cover e i t h e r no t est imated o r est imated t o have been l e s s than 1%. Where numbers a r e given, they approximate t h e percentage of the i s l a n d ' s a rea covered by a given vegetat ion type. I s lands which do n o t appear, e i t h e r were n o t s tudied from the vegetat ion stand- po in t , o r w i l l be t r e a t e d i n more d e t a i l i n fu tu re papers. For names of vegetat ion types see t e x t . VEGETATION TYPE - ~~- ISLAND NAME 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 Abel Key 100 Alina Key 100 Anegada x x 85 x 5 10 Bare Cactus x x x X X Beef I s l and x x x x x x x x Big Cockroach 1 0 80 10 Big Hans Lol l ick x x x x x Big Tobago x x 60 x 40 Blanquil la x 65 3 5 Booby Hatch x x x Botel la x 5 10 85 Byer Bache 100 Caballo Blanco 100 Cabez de Perro x x x x C a j a d e M u e r t o s x x x x x Caiia Azul 90 5 5 Cayo Ahogado 75 25 5 Cayo Batata x x x Cayo Enmedio 20 5 75 Cayo Enrique x x x Cayo Gi lber to 100 Cayo Isabel 100 Cayo Majimo 5 5 90 Cayo Norte x x x x x x Cayo Olga 100 Cayo Santiago x x x x x x x Cayo Turramotecito 90 10 Chicken I s l and x x x x x Cooper Is land x 1 4 50 x 4 0 5 Cucaracha x x (Las Cucarachas) Culebra x x x x x x x x x x x Culebri t a x x x x x x Dead Man's Chest x 3 48 1 4 8 De se cheo x x x x x x Diablo x x x Double Is land 45 50 5 Eas t ~ a r a l l 6 n 75 25 Table 2 c o n t ' d . - E a s t ~ e n i q u i E a s t S e a l Dog E u s t a t i a F a l l e n Jerusalem Frank Key Frenchman' s Cap (French Cap Key) Frenchman ' s Cay George Dog Ginger I s l a n d Grant Rock Green Cay (Near S t . Croix) Guana Gusano Herb Key Hicacos I s l a n d 0 I s l a n d Q I s l a n d R I s l e t a Marina Jos6 Key J u l i e Key Key R e i s t Konyoki La Gata ( I s l a La Gata) Laurel Levin ' s Rock L i t t l e Hans L o l l i c k L i t t l e Saba I s l a n d L i t t l e Tobago Long Key Magueyes Mangrove Key Marina Cay Mata Seca Media Luna Minnesota Mangrove Mona Mon i t o Mosquito I s l a n d Necker I s l a n d Norman I s l a n d Outer Caracol (Cavo Caracoles) Pa lomini tos Palominos Table 2 cont 'd. Pelican Key Peter Is land P l a t i l l o Prickly Pear Protes tant Key Puerto Rico Ramos Ratones (Cayo Ratones) Romero I1 Romero I11 Round Key Sa i l Rock S a l t Is land San Cristobal Sheila Rock So l i t o (Cayo Sol i to ) Spaghetti Key Spiny Butte S t . Croix S t . John St . Thomas Surprise Key Tortola Turramo t e Vieques Vi l l a del Mar Virgin Gorda Watson Rock West Dog West ~ a r a l l 6 n West Seal Dog 9 0 5 5 X X X X X X X X X X X X X X 7 0 3 0 X X X X X X X X X X X X X X X X X X X X X X X X X x x x 80 6 4 10 x 100 6 5 5 30 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X 20 50 15 15 X X X X X X X X X X X 25 50 25 X X X X X X X X X X X 90 5 5 X X X X X X X X X X X 90 x 5 5 X X X X 95 5 x 25 60 15 SPINY BUTTE ROUND KEY CAYO ENMEDlOo S A N CRlSTOBALo oLAUREL L I T T L E M E D I A LUNAO 'MEDIA TURRAMOTECITO LUNA D~~~~~ T U R R A M O T E CAYO TERREMOTOO 0 km 2 +Q PALOMINOS 0 P A L O M l N l T O S .CAY0 A H O G A D O PUERTO c 3 1 S L A C A B R A S QCAYO ALGODONES 0 km 2 w L A S C U C A R A C H A S 0-.. EAST FARALLON WEST FARAILON-.. , 'fc , S H E I L A ROCK . . H I C A Q U I H l CACOS C A Y 0 RATONES K O N YOK l PRESSICK ROCK AUDRY ROCK-* &<- DOUBLE I S L A N D C A Y 0 LOBOS R , 6 SURPRISE KEY '.$ < BOOBY ROCK B L A N Q U I L L A 2 O- 0. G R A N T ROCK M A C K E N Z I E KEY P 0 0 . 0 . / CAYO SOLITO-0 0 LOS H E R M A N O S O CAY0 oROCA BALLENA NORTE OROCA T I BURON owEST GENlQUl -EAST GENlQUl QBARE CACTUS Appendix I. Maps o f small i s l a n d s on t h e Puer to Rican Bank. Incons is tency i n use o f "cay" and "key" r e f l e c t s d i f f e r e n c e s between t h e American and B r i t i s h Vi rg in I s l a n d s i n t h e way t h e word i s s p e l l e d . We p r e f e r t h e former and use it u n l e s s "key" is p a r t of t h e proper name o f an i s l a n d . Cays i n the La Parguera reg ion of Puer to Rico (enlargement of r e c t a n g l e A i n Figure 1). Cays immediately e a s t of Pue r to Rico (enlargement o f r e c t a n g l e B i n Figure 1) . 1. Levin' s Rock Cays between Pue r to Rico and Culebra I s l a n d (enlargement of r e c t a n g l e C i n F igure 1 ) . Culebra I s l a n d and i t s surrounding cays (enlargement of r e c t a n g l e D i n Figure 1) . 1. Chicken I s l a n d , 2 . Mangrove Key. The i s l a n d s and cays of t h e American and B r i t i s h Vi rg in I s l a n d s , except f o r S t . Croix and i t s nearby i s l e t s (enlargement o f r e c t a n g l e E i n F igure 1) . S a i l Rock Savanna I s l a n d C r i c k e t Rock Cockroach I s l a n d (nea r S t . Thomas) Dutchman' s Cap S a l t Cay West Cay L i t t l e Saba I s l a n d Outer Brass I s l a n d Inner Brass I s l a n d Hassel I s l a n d Water I s l a n d Buck I s l a n d (nea r S t . Thomas) Cape1 l a I s l a n d Frenchman's Cap (French Cap ~ e y ) L i t t l e Hans Lo l l i ck Big Hans Lo l l i ck Thatch Key Grea t e r S t . James L i t t l e S t . James Big Tobago L i t t l e Tobago Mingo Key Congo Key Lovango Key J o s t van Dyke L i t t l e J o s t van Dyke Sandy Key Great Thatch I s l a n d L i t t l e Thatch I s l a n d Frenchman's Key Leduck I s l a n d Flannigan I s l a n d Norman I s l a n d P e t e r I s l a n d Dead Man's Chest S a l t I s l a n d Cooper I s l a n d Ginger I s l a n d Round Rock F a l l e n Jerusalem Guana I s l a n d Buck I s l a n d (near Tor to l a ) Beef Is land Marina Cay Scrub I s l a n d Grea te r Camanoe The Dog I s l a n d s : George Dog, West Dog, Great Dog and Big Cockroach ( n e a r Vi rg in Gorda) Sea l Dogs: E a s t Sea l Dog and West Se-.?l Dog Mosquito I s l a n d P r i c k l y Pear Necker I s l a n d Watson Rock Pe l i can Key 55. A s e r i e s of t i n y cays, R , 0 , Q and Byer Bache 56. Green Cay ( J o s t van Dyke) 57. Sandy S p i t 58. Eus ta t i a 59. Saba Rock 60. L i t t l e Camanoe 61. Broken Jerusalem Appendix 11. F l o r a l l ists from some small i s l ands and cays i n the Puerto Rican and Virgin Is land area. These should be considered a s p lan t records ra the r than complete f l o r a s except f o r those i s l a n d s marked with an ( * ) f o r which attempts were made t o c o l l e c t a l l species. Major i s l ands not included; f o r treatment of t h e i r f l o r a and vegetat ion see Br i t ton and Wilson (1923-30) , Gleason and Cook (192 7) , L i t t l e and Wadsworth (1964) and Dansereau (1966) . Byer has a long-term, comprehensive study of the f l o r a of small i s l ands of t h i s region i n progress. ANEGADA See D ' Arcy (1971, 1975) BIG BIG B I G COCKROACH Cephalocereus r o y e n i Opuntia d i l l e n i i HANS LOLLICK Thr inax argen t e a P i s c i d i a p i s c i p u l a C i t harexy lum f r u t i c o s u m Torrubia f ragrans (?) P i thecellobi um unguis-ca ti Croton a s t r o i t e s Agave mi ss ionum Vigna marina Coccol oba u v i f e r a Hippomane m a n c i n e l l a Bursera simarouba Capparis i n d i c a (?) TOBAGO Conocarpus e r e c t a Croton a s t r o i t e s B u l b o s t y l i s v e s t i t a Agave miss ionum Cephalocereus r o yeni Tabebuia h e t e r o p h y l l a P i t h e c e l l o b i u m u n g u i s - c a t i Torrubia f ragrans Bursera simarouba Opuntia r e p e n s CAYO CANA CAYO CAYO CAYO CAYO CAYO CAYO AHOGADO See Heatwole and ~ e v i n s (1973) AZUL * Avicenn ia n i t i d a R h i zophora mangle BATATA See Heatwole, Sade and Hildreth (1963) ENMEDIO * Sesuvium por tu lacas t rum ENRIQUE * Sesuvium por tu lacas t rum MAJIMO * S e s u v i um p o r t u lacas t rum SANTIAGO See Heatwole, Sade and Hildreth (1963) TURREMOTECITO * Sesuvium p o r t u l a c a s t r u m COOPER ISLAND Bursera simarouba C a k i l e l a n c e o l a t a Car i c a papaya Coccoloba u v i f e r a Cocos n u c i f e r a Cro ton a s t r o i tes Euphorbi a b u x i f 01 i a Musa s p . Sporobol u s v i r g i n i c u s DOUBLE KEY * S e s u v i um p o r t u l a c a s t r u m DEAD MAN'S CHEST Coccol oba u v i f e r a Cro ton a s t r o i t e s Croton s p . Sesuvium p o r t u l a c a s t r u m Sporobo lus v i r g i n i c u s EAST FARALLON * Sesuvium p o r t u l a c a s t r u m EUSTATIA Bursera simarouba C a k i l e l a n c e o l a t a Cocos n u c i f e r a Cro ton a s t r o i tes Hippomane m a n c i n e l l a Sporobol u s vi r g i n i c u s FALLEN JERUSALEM Bursera simarouba Coccoloba u v i f e r a Croton a s t r o i tes Tabebuia h e t e r o p h y l l a FRENCHCAP CAY Canaval ia mari t ima Clerodendron acu lea tum Cyperus p l a n i f o l i u s F i c u s l a e v i g a t a Hippomane m a n c i n e l l a Mollugo v e r t i c i l l a t a Por tu laca g r a n d i f l o r a GEORGE DOG ISLAND Bursera simarouba Coccol oba u v i f e r a GINGER ISLAND Avi cenn ia n i t i d a Bursera simarouba C r o t o n a s troi tes Croton r i g i d u s P i s o n i a subcorda ta HICACOS See B r i t t o n (1924) ISLAND 0 * Rhi zophora mangle ISLAND R * Rhi zophora mangle ISLAND Q * Borri chi a a r b o r e s c e n s Laguncular ia racemosa Rhi zophora mangle S a l i c o x n i a ambigua Sesuv ium p o r t u l a c a s t r u m L E V I N S ROCK * Canaval ia mari t i m a E r i t h r a l i s f r u t i c o s a Paspal um g l abrum L I T T L E HANS LOLLICK Bursera simarouba Cephalocereus r o y e n i Coccoloba u v i f e r a Croton a s troi tes C r o t o n discolor Hippomane m a n c i n e l l a Jacqu in ia barbasco Opunt ia d i l l e n i i Opunt ia r e p e n s Opunt ia r u b e s c e n s P i thecel l o b i u m u n g u i s - c a t i R i v i n a h u m i l i s Sporobo lus v i r g i n i c u s T h r i n a x argen t e a Torrub ia f r a g r a n s L I T T L E SABA Cephal o c e r e u s r o y e n i Conocarpus e r e c t a Rh i zophora mangle L I T T L E TOBAGO Agave mi s s ionum Bursera s imarouba C e p h a l o c e r e u s r o y e n i Croton a s t r o i tes Jacquemon t i a jamai censis Lantana i n v o l u c r a t a Opun t ia d i l l e n i i P i t h e c e l l o b i u m u n g u i s - c a t i S p o r o b o l u s v i r g i n i c u s Torrub ia f r a g r a n s V igna marina MOSQUITO ISLAND Bursera simarouba C a r i ca papaya Coccol oba u vi f e r a Croton a s t r o i tes Hippomane m a n c i n e l l a Sporobo l u s v i r g i n i c u s Tabebuia he t e r o p h y l l a T o r r u b i a f r a g r a n s ( ?) NECKER Bursera s imarouba C a c t u s i n t o r t u s C e p h a l o c e r e u s r o y e n i Coccol oba u vi f e r a Cro ton a s t r o i tes Croton r i g i d u s G u i l a n d i a c r i s t a NORMAN ISLAND Amaranthus d u b i u s A t r i p l e x s p . Bursera s imarouba Cappari s f l exuosa Coccoloba u v i f e r a Conocarpus e r e c t a Croton a s t r o i tes Euphorbi a s p . Laguncul a r i a racemosa P i soni a a1 bi da Sporobol u s v i r g i n i c u s Tamarindus i n d i c a PALOMINITOS * B o r r i chi a a r b o r e s c e n s C a k i l e l a n c e o l a t a Canava l ia mari t i m a Cassy tha f i l i f o r m i s Cenchrus e c h i n a t a Cenchrus p a u c i f l o r u s Coccoloba u v i f e r a Conocarpus e r e c t a Cyperus p l a n i f o l i u s E r e t h r a l i s f r u t i c o s a Ermodia 1 i t t o r a l i s Euphorbia b u x i f o l i a Lantana i n v o l u c r a t a Melanthera n i v e a S c a e v o l a p lumer i Sesuv ium p o r t u l a c a s t r u m S u r i a n a mari t ima V igna marina 3 u n i d e n t i f i e d PELICAN KEY Cappar i s f l e x u o s a Conocarpus e r e c t a Laguncu lar ia racemosa ( d i s a p p e a r e d again before June 1968) Opunt ia r e p e n s P o r t u l a c a o l e r a c e a Sporobol u s v i r g i n i c u s PLATILLO Coccol oba u v i f e r a PRICKLY PEAR Agave mi s s ionum Bursera simarouba RATONES Coccol oba u v i f e r a S A I L ROCK * B a r r e n SALT ISLAND Cocos n u c i f e r a Croton a s t r o i t e s SAN CRISTOBAL * Avicenn ia n i t i d a Laguncular ia racemosa P h i l o x e r u s v e r m i c u l a r i s R h i zophora mangl e Sesuvium por tu lacas t rum SHEILA ROCK * S e s u v i um p o r t u l a c a s trum SOLITO * S e s u v i um p o r t u l a c a s t r u m SPINY BUTTE * Acuan v i r g a tum Ayenia p u s i l l a Boerhaavi a e r e c t a Bursera simarouba Capparis fl exuosa Commel i n a el egans Cordia a n g u s t i f o l i a Croton d i s c o 1 or Croton h u m i l i s Euphorbi a b e r t e r i a n a H i b i s c u s b r a s i l i e n s i s Hippomane m a n c i n e l l a Lantana i n v o l u c r a t a Lep tocereus q u a d r i c o s t a t u s M o l l uch ia tomentosa Opuntia d i l l e n i i Panicum maximum P e c t i s l i n i f o l i a P i thecell obi um u n g u i s - c a t i Por tu laca p i 1 osa Pteramnus l a b i a l i s Rauwol f ia l a m a r c k i i Rhizophora mangle R u e l l i a t u b e r o s a S i d a glabra S i da procumbens S t igmaphy l lon l i n g u l a t u m 3 uniden t i f i ed TURREMOTO (CORRAL) Avicenn ia n i t i d a Laguncular ia racemosa WEST DOG ISLAND Coccol oba u vi f e r a Conocarpus e r e c t a Croton r i g i d u s WEST FARAWLON * Sesuvium p o r t u l a c a s t r u m WEST SEAL DOG Coccol oba u v i f e r a Appendix 111. R e p t i l e s and Amphibians o f t he Puerto Rico - Virgin I s l and Archipelago The i s l a n d s from which each spec ies was c o l l e c t e d a r e l i s t e d f i r s t , ,followed by a l i s t i n g of a l l of t h e herpetofauna f o r each i s l and . An a t tempt was made t o do a complete survey on each i s l a n d . These l ists a r e based on our own c o l l e c t i o n s , those of var ious museums, l i t e r a t u r e records up t o 1970 which we have n o t v e r i f i e d ( * I , and our own s i g h t records (**I . They do no t include t h e records obta ined by o the r i n v e s t i g a t o r s a f t e r 1972, and whose c o l l e c t i o n s we have n o t seen. Some of these l a t e r c o l l e c t i o n s add spec ie s f o r i s l a n d s we have surveyed and p r e s e n t records from a number of i s l a n d s we d i d no t v i s i t . A complete l i s t i n g of t h e known i n s u l a r d i s t r i b u t i o n s of t h e Puerto Rican - Virgin I s l and spec ies can be obta ined from a combination of t h e p r e s e n t paper , and the pub l i ca t ions of Schwartz and Thomas (1975) , Phi l ibos ian and Yntema (1976, i n p r e s s ) and Maclean e t a l . (1977). I n our l ist , i s l a n d names i n parentheses i n d i c a t e t h a t t h e spec ie s i n ques t ion was recorded from t h a t i s l a n d b u t probably does n o t occur t h e r e a s a permanently e s t a b l i s h e d breeding populat ion. This l i s t c o r r e c t s t h a t of Schwartz and Thomas (1975) f o r Anolis c r i s t a t e l l u s c r i s t a t e l l u s and Anolis c r i s t a t e l l u s w i l e y a e i n l i n e with t h e taxonomic assessment of Heatwole (1976b). Schwartz and Thomas ind ica t ed A. c. c r i s t a t e l l u s t o i n h a b i t many i s l a n d s e a s t of Puer to Rico, which a r e i n f a c t i nhab i t ed by A. c . w i l e y a e i n s t ead . D i s t r ibu t ion of S ~ e c i e s LIZARDS I uuan idae A n o l i s a c u t u s Buck I s l a n d (near S t . Croix) P r o t e s t a n t Key Green Key (near S t . Croix) S t . Croix Anolis cooki Caja de Muertos Puerto Rico Anolis c r i s t a t e l l u s c r i s t a t e l l u s Algodones I s l e t a ~ a r i n a ' Caja de Muertos Long I s l and Cardona Key Magueyes I s l and (Cayo Ahogado ) P l a t i l l o Cayo Bata ta Puerto Rico Cayo Santiago Ramo s Also hybr ids between A. c. c r i s t a t e l l u s and A. c . w i l e y a e . Anol i s cri s ta tell us wi 1 e yae Algodones Anegada Bare Cactus I s l and Beef I s l a n d (near Tor to la ) B lanqu i l l a Booby Hatch B o t e l l a I s l a n d * Buck I s l a n d (near S t . Thomas) Cabeza de Per ro Cayo Lobos Cayo Norte Cayo Ratones (near Hicacos) Chicken I s l a n d Cockroach I s l a n d (near S t . Thomas) Cooper I s l a n d Congo Cay Culebra Cu leb r i t a Dead Man ' s Chest I s l e t a Marina Konyokf L i t t l e Camanoe L i t t l e Hans Lo l l i ck L i t t l e J o s t van Dyke L i t t l e Saba (near S t . Thomas) * L i t t l e S t . James L i t t l e Tobago * Lovango Key Marina Cay Mosquito I s l a n d Norman I s l and Necker I s l a n d Palomini tos Palominos Pe te r I s l a n d Piiieros P i f ie r i tos P r i c k l y Pear I s l and Puer to ~ i c o l Diablo * Dog I s l a n d * Dutchman's Cap Eas t Sea l Dog E u s t a t i a Fa l l en Jerusalem George Dog I s l a n d Ginger I s l a n d Grant Rock * Great Dog I s l a n d Grea ter Camanoe Grea ter Thatch I s l and Green Cay (near Tor to la ) Guana I s l and Hans Lo l l i ck * Hassel I s l a n d Hicacos * Inner Brass I s l a n d I s l a Cabras (near Roosevelt Rds P.R.) Ramos * S t . James S t . John S t . Thomas S a l t I s l a n d * S a l t Key Sandy Cay (near Tor to la ) Sandy S p i t * Savanna I s l and Scrub I s l and Surp r i se Key Tobago Tor to la Vieques V i l l a d e l Mar Virgin Gorda * Water I s l a n d ** West Dog I s l a n d West Sea l Dog I s l a n d Anol i s cuvi eri Puerto Rico * Vieques Also hybr ids between A. c. cristatellus and A. c. wileyae. An01 i s desechensi s De se cheo Anoli s evermanni Puerto Rico Anoli s gundlachi Puerto Rico Puerto Rico Mona Anolis krugi An01 i s monensi s Monito Anolis occul tus Puerto Rico Anolis poncensis Puerto Rico m o l i s pulchellus Algodones Anegada Cabeza de Perro Ca ja de Muertos (Cayo hoga ado) Cayo Batata Guana Island Hicacos I s l e t a Marina * Jos t van Dyke L i t t l e Jos t van Dyke * L i t t l e St . James * Lovango Key Palominos Peter Is land Cayo Norte Cayo Ratones (near Hicacos) Cayo Santiago Culebra * Fallen Jerusalem Greater Camanoe Piiieros Puerto Rico * St. James S t . John S t . Thomas Tortola Vieque s Virgin Gorda * Water Is land An01 i s roosevel ti * Culebra A n o l i s s t r a t u l u s Beef Is land (near Tortola) Cayo Santiago * Congo Key Culebra Fallen Jerusalem Ginger Is land Greater Camanoe Greater Thatch Is land Guana Island * J o s t van Dyke L i t t l e J o s t van Dyke * L i t t l e Saba (near S t . Thomas) Marina Cay Necker Is land Norman Is land * Peter Is land Piiieros Pr ickly Pear Puerto Rico S t . John S t . Thomas * Savanna Island Scrub Is land Tortola Vieques Virgin Gorda * Water Is land C y c l u r a c o r n u t a Mona Ane gada Cyc l u r a p i n g u i s Iguana i g u a n a * Guana Is land * S t . Croix * Hassel Is land * St . John Hicacos (pers . com. S.D. Garber) * St . Thomas Peter Island * Tortola Puerto Rico * Water Is land Te i i dae Mona Desecheo Ameiva a l b o g u t t a t a Amei va d e s e c h e n s i s Ameiva e x s u l Algodones Anegada Beef I s l and Blanquil la * Buck Is land (near Tortola) Cabeza de Perro Caja de Muertos (Levin' s Rock) L i t t l e Camanoe L i t t l e Hans Loll ick L i t t l e J o s t van Dyke L i t t l e Saba (near St . Thomas) L i t t l e St . James Lovango Key * Cardona Key (Cayo Ahogado) Cayo Batata Cayo Lobos Cayo Norte Cayo Ratones Cayo Santiago Cooper I s l and Culebra Culebr i ta Dead Man's Chest Diablo * Dutchman's Cap Eus ta t i a George Dog I s l and Ginger I s l and Greater Camanoe Guana Is land ~ a n s Lol l ick Hassel I s l and Hicacos Inner Brass I s l e t a Marina ~ o n y o k i Marina Cay Mosquito I s l and Necker I s l and Norman Is land Palominitos Palominos Pe te r I s l a n d Piiieros P l a t i l l o Pr ickly Pear Puerto Rico Ramos S t . James S t . John St . Thomas S a l t I s land * S a l t Key Savanna I s l and Scrub I s l a n d Tobago Tortola Vieques Virgin Gorda Water Is land Amei va pol ops Green Key (near S t . Croix) * S t . Croix Pro tes tan t Key Ameiva wetmorei Caja de Muertos Magueyes I s l and Puerto Rico Scincidae Mabu ya mabou ya sl oanei * Anegada Buck I s l and (near St . Cayo Norte * Culebra * Culebr i ta Dead Man's Chest ** Ginger I s l and Hicacos * J o s t van Dyke * L i t t l e Saba (near S t . Mona Thomas) ** Monito Necker I s l a n d Pe te r I s l and Puerto Rico * St . John * St . Thomas S a l t I s land * Vieques (Perhaps now l o c a l l y e x t i n c t ) Thomas ) Virgin Gorda Diploglossus pleii Puer to Rico Gekkonidae Hemidact yl us brooki Puer to Rico Hemi dactyl us mabouia Culebra * J o s t van Dyke Mona P e t e r I s l a n d Puer to Rico S t . Croix * S t . John S t . Thomas * S a l t I s l a n d Tobago Tor to l a Vieques * Water I s l a n d Phyllodactylus wirshingi * Caja de Muertos * Puerto Rico Sphaerodactylus beattyi beattyi Buck I s l a n d (near S t . Croix) S t . Croix Green Key ( n e a r S t . Croix) Sphaerodact yl us beat t yi seamani * S t . Croix Sphaerodactylus gai geae Cayo Sant iago Piiieros Puer to Rico Sphaerodactylus klauberi Puer to Rico Sphaerodactylus levinsi Desecheo I s l a n d Sphaerodactylus macrolepis ateles Puer to Rico Sphaerodact y l u s m a c r o l e p i s grandisquamis Algodone s Cayo Santiago Cabeza de Perro Puerto Rico Cayo Batata Sphaerodactylus macrolepis guarionex Puerto Rico S p h a e r o d a c t y l u s m a c r o l e p i s i n i g o i * Cayo de Afuera Vieques * Cayo de Tierra S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Ane gada Bare Cactus Island Beef Island Big Cockroach Botella * Buck Island (near S t . Thomas) Cooper Island * Congo Key Culebra Culebri ta Dead Man's Chest East Geniquf East Seal Dog Eusta t ia Fa1 len Jerusalem George Dog Island Ginger Is land Great Dog Island Greater Camanoe Greater Thatch Green Cay (near Tortola) Guana Is land Hans Lollick J o s t van Dyke L i t t l e Camanoe L i t t l e Hans Lollick L i t t l e J o s t van Dyke L i t t l e Saba * L i t t l e St. James L i t t l e Thatch Island Buck Island (near St . Croix) * Buck Island (near Tortola) * Cayo Luis Pefia Cayo Norte Chicken Island Cockroach (near S t . Thomas) L i t t l e Tobago Marina Cay Mosquito Necker Island Norman Island Peter Is land Prickly Pear S a i l Rock St. Croix S t . John S t . Thomas S a l t Island Sandy Cay (near Tortola) Sandy Sp i t * Savanna Island Scrub Is land Tobago Tortola V i l l a del Mar Virgin Gorda * Water Is land Watson Rock West Dog Island West Seal Dog Is land Sphaerodac ty l u s m a c r o l e p i s mime tes Puerto Rico Sphaerodactylus macrolepis phoberus Puerto Rico Sphaerodact yl us macro1 epis spani us Puerto Rico Sphaerodactylus macrolepis stibarus Piiieros Sphaerodactylus monensis Mona Sphaerodactylus nicholsi nicholsi Magueyes Island Puerto Rico Spiny Butte (Turramote Key) Sphaerodact ylus ni cholsi townsendi Blanquilla Booby Hatch Caja de Muertos * Cayo de Afuera (near ~ i e q u e s ) * Cayo de Tierra (near ~ i e q u e s ) Cayo Lobos Cayo Ratones (near ~ i c a c o s ) * Culebra Diablo French Cap Key Grant Rock Hicacos I s l a Cabras (near Roosevelt Rds., P.R.) Konyokf MacKenzie Key Palominos Piiieros P l a t i l l o Puerto Rico Ramos Surprise Key Vieques Sphaerodact yl us parthenopi on Mosquito Is land Virgin Gorda Sphaerodactylus roosevel ti Caja de Muertos Magueyes Island Necker Island Puerto Rico * Vieques Thecadactylus rapicaudus * S t . Croix AMPHISBAENIANS Amphisbaenidae Amphisbaena bakeri Puerto Rico Puerto Rico Amphisbaena caeca Amphisbaena fenes trata * Greater Camanoe L i t t l e J o s t van Dyke * St . James * St . John * St . Thomas * Tortola * Virgin Gorda Amphisbaena schmi d ti Puerto Rico Amphisbaena xera Caja de Muertos (ca l l ed A. caeca Puerto Rico by Heatwole et al. 1965) SNAKES Boidae Epi cra tes inorna tus Puerto Rico * Mona picr rates monensis * Tortola Colubridae Alsophis portori censis Anegada Mona Buck Island (near S t . Thomas) Mosquito Cabeza de Perro Necker Is land Ca ja de Muertos Norman Island Cayo Santiago * Peter Island Cockroach (near St . Thomas) P l a t i l l o Culebra Puerto Rico Ginger Island * St . John Green Cay (near Tortola) * St . Thomas Guana Is land * S a l t Island * J o s t van Dyke * L i t t l e Saba L i t t l e Tobago * Savanna Island * Vieques Virgin Gorda A l s o p h i s s a n c t i c r u c i s * St . Croix ~ r r h y t o n e x i guum Anegada Cayo Santiago * Culebra Greater Camanoe * Hassel Island Peter Island Puerto Rico * St. John St . Thomas Tortola Virgin Gorda Typhlopidae ~ y p h l o p s gran ti Puerto Rico ~ y p h l o p s monens i s Mona ~ y p h l o p s ri c h a r d i Cayo Norte * Culebra Diablo Guana Island L i t t l e Hans Lollick L i t t l e J o s t van Dyke Palominitos Puerto Rico * St. Croix * St. John * St. Thomas Surprise Key Tortola Virgin Gorda ~ y p h l o p s r o s t e l l a t a Puerto Rico TURTLES (excluding marine ones ) Emydidae C h r ysemys d e c u s s a t a ste j n e g e r i Puerto Rico * St. John * S t . Thomas Tes tudinidae Geoche lone c a r b o n a r i a * Tortola * Water I s l and ANU RANS Bu ?on idae B u f o l emur Puerto Rico B u f o m a r i n u s ( introduced) A 1 godones Cayo Santiago Culebra Puerto Rico S t . Croix V i eques B u f o t u r p i s * Virgin Gorda Leptodactylidae E l e u t h e r o d a c t y l u s a n t i l l e n s i s Culebra Piiieros Puerto Rico S t . Croix (introduced?) S t . John St . Thomas Tortola Vieques Virgin Gorda E l e u t h e r o d a c t y l u s bri t toni Puerto Rico E l e u t h e r o d a c t y l u s cochranae * Hassel I s land Puerto Rico S t . John S t . Thomas Tortola E l e u t h e r o d a c t y l u s cooki Puerto Rico E l e u t h e r o d a c t y l u s c o q u i Puerto Rico E l e u t h e r o d a c t y l u s e n e i d a e Puer to Rico Puer to Rico E l e u t h e r o d a c t y l u s g r y l l u s ~l e u t h e r o d a c t y l u s h e d r e c k i Puer to Rico E l e u t h e r o d a c t y l u s k a r l s c h m i d t i Puer to Rico E l e u t h e r o d a c t y l u s l e n t u s S t . Thomas E l e u t h e r o d a c t y l u s 1 o c u s t u s S t . Croix Pue r to Rico E l e u t h e r o d a c t y l u s m o n e n s i s Mona E l e u t h e r o d a c t y l u s p o r t o r i c e n s i s Puer to Rico E l e u t h e r o d a c t y l u s r i chmond i Puer to Rico E l e u t h e r o d a c t y l u s s c h w a r t z i G r e a t Dog S t . Croix ( in t roduced?) S t . John Tor to l a Vi rg in Gorda E l e u t h e r o d a c t y l u s u n i c o l o r Puer to Rico E l e u t h e r o d a c t y l u s wightmanae Puer to Rico Leptodact y l u s a1 i b i l a b r i s Algodones Ane gada Cayo Santiago Culebra Hicacos Piiieros Puerto Rico Puerto Rico St . Croix S t . John S t . Thomas Tortola Vieques Rani dae Rana ca t e s b e i a n a (introduced) Vieques (J. E . Cooper, pe r s . com. Fauna of Is lands Algodone s Ameiva e x s u l Bu fo marinus (introduced) A n o l i s c r i s t a t e l l u s c r i s t a t e l l u s L e p t o d a c t y l u s a l b i l a b r i s A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodact yl u s m a c r o l e p i s grandis- A n o l i s p u l c h e l l u s quami s Anegada A1 s o p h i s p o r t o r i c e n s i s * Cyclura p i n g u i s Ameiva e x s u l L e p t o d a c t y l u s a l b i l a b r i s A n o l i s c r i s t a t e l l u s w i l e y a e * Mabuya mabouya s l o a n e i A n o l i s p u l c h e l l u s Sphaerodac ty lus m a c r o l e p i s macro lep i s * Arrhy ton exigum Bare Cactus Island A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodac ty l u s m a c r o l e p i s macro1 e p i s B e e f I s l and (near Tortola) Ameiva e x s u l A n o l i s s t r a t u l u s A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodac ty lus m a c r o l e p i s m a c r o l e p i s Big Cockroach S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Ameiva ex su l Sphaerodactylus n i c h o l s i townsendi A n o l i s c r i s t a t e l l u s wi leyae Booby Hatch A n o l i s c r i s t a t e l l u s wi leyae Sphaerodactylus n i c h o l s i townsendi Bote l l a Is land Ano l i s c r i s t a t e l l u s wi leyae Sphaerodactylus macrolepis macrolepis Buck Is land (near S t . Thomas) * A1 sophi s p o r t o r i c e n s i s * Mabuya mabouya s loane i * A n o l i s c r i s t a t e l l u s wi leyae * Sphaerodactylus macrolepis macrolepis Buck Is land (near St . Croix) Ano l i s acu tus Sphaerodact yl us macrolepis macro1 e p i s Sphaerodact yl u s b e a t t y i bea t t y i Buck Is land (near Tortola) Ameiva e x s u l * Sphaerodactylus macrolepis macrolepis Cabeza de Perro d l soph i s p o r t o r i c e n s i s A n o l i s pu l che l l u s Ameiva ex su l Sphaerodactylus macrolepis A n o l i s c r i s t a t e l l u s wi leyae grandisquamis Caja de Muertos Alsophis p o r t o r i c e n s i s A n o l i s c r i s t a t e l l u s c r i s t a t e l l u s Ameiva ex su l An01 i s pul chell u s Amei va we tmorei * Phyl lodac ty lus w i r sh ing i Amphi sbaena xera Sphaerodactylus n i cho l si townsendi A n o l i s cooki Sphaerodactylus r o o s e v e l t i Cardona Key Ameiva e x s u l * Ano l i s cris t a t e l l u s c r i s t a t e l l us Cayo Ahogado (Amei va e x s u l ) ( A n o l i s pu l che l l u s ) ( A n o l i s c r i s t a t e l l u s c r i s t a t e l l u s ) Cayo Bata ta Ameiva e x s u l A n o l i s p u l c h e l l u s A n o l i s c r i s t a t e l l u s c r i s t a t e l l u s Sphaerodac ty lus macro lep i s grand i s - quami s Cayo de Afuera * Sphaerodac ty l u s macrol e p i s i n i g o i "Sphaerodact y l u s n i c h o l si townsendi Cayo de T i e r r a * Sphaerodac ty l u s macrol e p i s i n i g o i *Sphaerodact y l u s nicholsi townsendi Cayo Lobos Ameiva e x s u l A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodact y l u s n i chol si townsendi Cayo Luis Peiia * Sphaerodac ty lus m a c r o l e p i s m a c r o l e p i s Cayo Norte Ameiva e x s u l Mabuya mabouya s l o a n e i A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodact y l u s m a c r o l e p i s m a c r o l e p i s A n o l i s p u l c h e l l u s Typhl o p s ri chard i Cayo Ratones Ameiva e x s u l An01 i s pul chell u s A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodact y l u s n i c h o l si townsendi Cayo Santiago A l s o p h i s p o r t o r i c e n s i s Arrh y ton Ameiva e x s u l B u f o marinus (introduced) A n o l i s c r i s t a t e l l u s c r i s t a t e l l u s L e p t o d a c t y l u s a l b i l a b r i s An01 i s pul chell u s Sphaerodact y l u s gaigeae Anolis s t r a t u l u s Sphaerodac ty lus macro1 e p i s grandis- quami s Chicken I s l and A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodac ty lus m a c r o l e p i s m a c r o l e p i s Cockroach (near St . Thomas) * A1 s o p h i s p o r t o r i c e n s i s Sphaerodact yl u s macro1 e p i s macro1 e p i s Anolis c r i s t a t e l l u s w i l e y a e Cooper I s l and Ameiva e x s u l A n o l i s c r i s t a t e l l u s w i l e y a e * A n o l i s cris t a t e l l u s w i l e yae * Anolis s t r a t u l u s S p h a e r o d a c t y l u s m a c r o l e p i s Congo Key * S p h a e r o d a c t y l u s macrol e p i s m a c r o l e p i s Culebra A1 s o p h i s p o r t o r i censis E l e u t h e r o d a c t y l u s a n t i l l e n s i s Ameiva e x s u l Hemidac ty l u s mabouia A n o l i s c r i s t a t e l l u s w i l e y a e L e p t o d a c t y l u s a l b i l a b r i s A n o l i s p u l c h e l l u s * Mabuya mabouya s l o a n e i * An01 i s roosevel ti S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Anolis s t r a t u l u s * S p h a e r o d a c t y l u s nicholsi t o w n s e n d i A r r h y t o n ex iguum * T y p h l o p s r i c h a r d i B u f o m a r i n u s (introduced) Culebr i ta Ameiva e x s u l * Mabuya mabouya s l o a n e i A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Dead Man's Chest Ameiva e x s u l A n o l i s c r i s t a t e l l u s w i l e y a e Amei v a d e s e c h e n s i s A n o l i s d e s e c h e n s i s Anolis c r i s t a t e l l u s w i l e y a e Ameiva e x s u l Mabuya mabouya s l o a n e i S p h a e r o d a c t y l u s m a c r o l e ~ i s m a c r o l e p i s Dese cheo S p h a e r o d a c t y l u s 1 evinsi S p h a e r o d a c t y l u s n i cholsi t o w n s e n d i T y p h l o p s r i c h a r d i Dog I s l and * Anolis c r i s t a t e l l u s w i l e y a e Dutchman ' s Cap Ameiva e x s u l * A n o l i s c r i s t a t e l l u s w i l e y a e East Geniqui S p h a e r o d a c t y l u s macrol e p i s macrol e p i s East Seal Dog A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s macro1 e p i s m a c r o l e p i s Eus ta t i a A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodac t y l u s m a c r o l e p i s macro1 e p i s ~ m e i v a e x s u l Fallen Jerusalem A n o l i s c r i s t a t e l l u s w i l e y a e Anolis s t r a t u l u s A n o l i s p u l c h e l l u s S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s French Cap K e y S p h a e r o d a c t y l u s n i c h o l si townsend i George Dog Is land Ameiva e x s u l S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s A n o l i s c r i s t a t e l l u s w i l e y a e Ginger Island A l s o p h i s p o r t o r i c e n s i s Anolis s t r a t u l u s Ameiva e x s u l * *Mabu ya mabou ya sl o a n e i An01 i s c r i s t a t e l l u s w i l e yae S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Grant Rock A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s n i c h o l s i t o w n s e n d i Great Dog Is land * A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s E l e u t h e r o d a c t y l u s s c h w a r t z i Greater Camanoe Ameiva e x s u l A n o l i s s t r a t u l u s * Amphi sbaena f e n e s t r a t a A r r h y t o n ex iguum A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Anolis p u l c h e l l u s Greater Thatch Is land A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s A n o l i s s t r a t u l u s Green Key (near St . Croix) Amei va p o l o p s S p h a e r o d a c t y l u s b e a t t y i b e a t t y i A n o l i s a c u t u s Green Cay (near Tortola) A1 s o p h i s p o r t o r i c e n s i s S p h a e r o d a c t y l u s m a c r o l e p i s i n a c r o l e p i s A n o l i s c r i s t a t e l l u s w i l e y a e Guana Island A1 s o p h i s p o r t o r i c e n s i s A n o l i s s t r a t u l u s Ameiva e x s u l * Iguana i g u a n a A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s macro1 e p i s m a c r o l e p i s A n o l i s p u l chell u s T y p h l o p s r i c h a r d i Hans Lollick Ameiva e x s u l S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s A n o l i s c r i s t a t e l l u s w i l e y a e Hassel Island Ameiva e x s u l * E l e u t h e r o d a c t y l u s cochranae * A n o l i s c r i s t a t e l l u s w i l e y a e * Iguana i g u a n a A r r h y t o n ex iguum Hicacos Ameiva e x s u l L e p t o d a c t y l u s a l b i l a b r i s A n o l i s c r i s t a t e l l u s w i l e y a e Mabu ya mabou ya s l o a n e i A n o l i s pu l c h e l l u s S p h a e r o d a c t y l u s nicholsi townsend i Iguana i g u a n a (pers. corn. S.D. Garber) Inner Brass Island Ameiva e x s u l A n o l i s c r i s t a t e l l u s w i l e y a e I s l a Cabras (near Roosevelt Rds . , P.R. ) A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s nicholsi t o w n s e n d i I s l e t a Marina Ameiva e x s u l A n o l i s c r i s t a t e l l u s w i l e y a e Anolis c r i s t a t e l l u s c r i s t a t e 1 l u s A . c . c r i s t a t e l l u s X A. c. w i l e y a e Anolis p u l c h e l l u s J o s t van Dyke * A l s o p h i s p o r t o r i c e n s i s * Hemidac ty l u s mabouia * Anolis p u l c h e l l u s * Mabuya mabouya s l o a n e i * A n o l i s s t r a t u l u s S p h a e r o d a c t y l u s m c r o l e p i s m a c r o l e p i s Konyokf Ameiva e x s u l S p h a e r o d a c t y l u s nicholsi townsend i Anolis c r i s t a t e l l u s w i l e y a e Levin' s Rock (Ameiva e x s u l ) L i t t l e Camanoe Ameiva e x s u l S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Anolis c r i s t a t e l l u s w i l e y a e L i t t l e Hans Loll ick A1 s o p h i s r i c h a r d i Ameiva e x s u l A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s macro l e p i s macro l e p i s L i t t l e J o s t van Dyke Amei v a e x s u l Anolis s t r a t u l u s Amphi sbaena f enes t r a t a S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Anolis c r i s t a t e l l u s w i l e y a e T y p h l o p s r i c h a r d i Anolis p u l c h e l l u s L i t t l e Saba (near S t . Thomas) * A l s o p h i s p o r t o r i c e n s i s * Anolis s t r a t u l u s Ameiva e x s u l * Mabuya mabouya s l o a n e i * Anolis c r i s t a t e l l u s w i l e y a e * S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s L i t t l e S t . James Ameiva e x s u l * Anolis p u l c h e l l u s * A n o l i s c r i s t a t e l l u s w i l e y a e * S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s L i t t l e Thatch Is land S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s L i t t l e Tobago A1 s o p h i s p o r t o r i censis S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Anolis c r i s t a t e l l u s w i l e y a e Long Is land A n o l i s c r i s t a t e l l u s c r i s t a t e l l u s Lovango Key * Anolis p u l c h e l l u s Ameiva e x s u l * Anolis c r i s t a t e l l u s w i l e y a e MacKenzie Key S p h a e r o d a c t y l u s nicholsi townsend i Magueyes Is land Amei va wetmorei Sphaerodac t y l u s n i cholsi n i chol si Anolis c r i s t a t e l l u s c r i s t a t e l l u s S p h a e r o d a c t y l u s roosevel ti Marina Cay Ameiva e x s u l A n o l i s s t r a t u l u s Anolis c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Mona A1 s o p h i s p o r t o r i c e n s i s Ameiva a l b o y u t t a t a An01 i s m o n e n s i s C y c l u r a c o r n u t a E l e u t h e r o d a c t y l u s monens i s An01 i s m o n e n s i s * Epi c r a tes monens i s Hemi d a c t y l u s mabouia Mabu ya mabou ya sl o a n e i S p h a e r o d a c t y l u s m o n e n s i s Typh l o p s monensi s Monito **Mabu ya mabouya s l o a n e i Mosquito Is land A1 s o p h i s p o r t o r i censi s S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Ameiva e x s u l S p h a e r o d a c t y l u s p a r t h e n o p i o n Anolis c r i s t a t e l l u s w i l e y a e Necker Is land A1 s o p h i s p o r t o r i censis Mabu ya mabou ya s l o a n e i Ameiva e x s u l S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Anolis c r i s t a t e l l u s w i l e y a e T h e c a d a c t y l u s r a p i caudus A n o l i s s t r a t u l u s Norman I s l a n d d l soph i s p o r t o r i c e n s i s Anolis s t r a t u l u s Ameiva e x s u l Sphaerodacty l u s macro1 e p i s macrolepi s Anolis c r i s t a t e l l u s w i l e y a e Palomin i tos dineiva e x s u l Typhl o p s r i c h a r d i Anolis c r i s t a t e l l u s w i l e y a e Palominos dmeiva e x s u l A n o l i s p u l c h e l l u s A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodact y l u s n i c h o l si townsendi P e t e r I s l a n d * d l s o p h i s p o r t o r i c e n s i s d r r h y ton exiguum dineiva e x s u l Hemidactyl u s mabouia A n o l i s c r i s t a t e l l u s w i l e y a e Iguana iguana A n o l i s p u l c h e l l u s Mabuya mabouya s l o a n e i * Anolis s t r a t u l u s Sphaerodac ty lus m a c r o l e p i s macro lep i s dineiva e x s u l L e p t o d a c t y l u s a l b i l a b r i s A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodac ty lus gaigeae Anolis p u l c h e l l u s Sphaerodac ty lus m a c r o l e p i s s t i b a r u s A n o l i s s t r a t u l u s Sphaerodact y l u s n i c h o l si townsendi E leu therodac t yl u s a n t i l l e n s i s P i i i e r i t o s d n o l i s c r i s t a t e l l u s w i l e y a e d l s o p h i s p o r t o r i c e n s i s Anolis c r i s t a t e l l u s c r i s t a t e l l u s **dineiva e x s u l Sphaerodact y l u s n i c h o l si townsendi P r i c k l y Pea r I s l a n d Ameiva e x s u l Anolis s t r a t u l u s A n o l i s c r i s t a t e l l u s w i l e y a e Sphaerodac ty lus m a c r o l e p i s m a c r o l e p i s P r o t e s t a n t Key Amei va polops A n o l i s a c u t u s Puerto Rico A1 s o p h i s p o r t o r i censis Ameiva e x s u l Anolis s t r a t u l u s Amei va we t m o r e i A r r h y t o n ex iguum Amphisbaena b a k e r i B u f o l emur Amphisbaena caeca ~ u f o mar inus (introduced) Amphisbaena s c h m i d t i Chrysemys d e c u s s a t a s t e j n e g e r i Amphisbaena x e r a D i p l o g l o s s u s p l e i i Anolis cooki E l e u t h e r o d a c t y l u s a n t i l l e n s i s A n o l i s c r i s t a t e l l u s c r i s t a t e l l u s E l e u t h e r o d a c t y l u s brittoni Anolis c r i s t a t e l l u s w i l e y a e E leu t h e r o d a c t y l u s cochranae Anolis c. c r i s t a t e l l u s X A. c. E l e u t h e r o d a c t y l u s cooki w i l e y a e A n o l i s c u v i e r i Anolis evermanni Anolis g u n d l a c k i Anolis k r u g i An01 i s o c c u l t u s Anolis p o n c e n s i s Anolis p u l c h e l l u s E l e u t h e r o d a c t y l u s r i chmondi E l e u t h e r o d a c t y l u s u n i c o l o r E l e u t h e r o d a c t y l u s wightmanae E p i c r a t e s i n o r n a t u s H e m i d a c t y l u s brooki Hemidacty l u s mabouia Iguana i guana L e p t o d a c t y l u s a l b i l a b r i a Mabuya mabouya s l o a n e i * P h y l l o d a c t y l u s w i r s h i n g i Rana c a t e s b e i a n a (introduced) S p h a e r o d a c t y l u s g a i g e i S p h a e r o d a c t y l u s k l a u b e r i Ameiva e x s u l E leu t h e r o d a c t y l u s c o q u i E leu t h e r o d a c t y l u s e n e i d a e E l e u t h e r o d a c t y l u s g r y l l u s E l e u t h e r o d a c t y l u s h e d r e c k i E l e u t h e r o d a c t y l u s k a r l s c h m i d t i E l e u t h e r o d a c t y l u s l o c u s t u s E l e u t h e r o d a c t y l u s p o r t o r i c e n s i s S p h a e r o d a c t y l u s m a c r o l e p i s a t e l e s Sphaerodac t y l u s m a c r o l e p i s g r a n d i s - quamis S p h a e r o d a c t y l u s m a c r o l e p i s g u a r i o n e x S p h a e r o d a c t y l u s m a c r o l e p i s m i m e t e s S p h a e r o d a c t y l u s m a c r o l e p i s phoberus S p h a e r o d a c t y l u s m a c r o l e p i s s p a n i u s S p h a e r o d a c t y l u s nicholsi nicholsi S p h a e r o d a c t y l u s nicholsi townsend i S p h a e r o d a c t y l u s roosevel ti Typh lops g r a n t i Typhl o p s r i c h a r d i Typh lops r o s t e l l a t a Ramo s Anolis c r i s t a t e l l u s w i l e y a e Anolis c r i s t a t e l l u s c r i s t a t e l l u s S p h a e r o d a c t y l u s nicholsi townsend i S a i l Rock S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s St . Croix * A l s o p h i s s a n c t i c r u c i s H e m i d a c t y l u s mabouia * Ameiva p o l o p s * Iguana i g u a n a A n o l i s a c u t u s L e p t o d a c t y l u s a l b i l a b r i s B u f o m a r i n u s ( introduced) S p h a e r o d a c t y l u s b e a t t y i b e a t t y i E l e u t h e r o d a c t y l u s a n t i l l e n s i s * S p h a e r o d a c t y l u s b e a t t y i seamani ( introduced? ) E l e u t h e r o d a c t y l u s 1 en t u s S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s E l e u t h e r o d a c t y l u s s c h w a r t z i * T h e c a d a c t y l u s r a p i c a u d u s ( introduced? * T y p h l o p s r i c h a r d i S t . James Ameiva e x s u l * Anolis c r i s t a t e l l u s w i l e y a e * Amphisbaena f e n e s t r a t a * Anolis p u l c h e l l u s S t . John * A l s o p h i s p o r t o r i c e n s i s E l e u t h e r o d a c t y l u s cochran a e Ameiva e x s u l E l e u t h e r o d a c t y l u s s c h w a r t z i * Amphisbaena f e n e s t r a t a Geochelone c a r b o n a r i a Anolis c r i s t a t e l l u s w i l e y a e * H e m i d a c t y l u s mabouia Anolis p u l c h e l l u s * Iguana i g u a n a A n o l i s s t r a t u l u s L e p t o d a c t y l u s a l b i l a h r i s * A r r h y t o n ex iguum * Mabuya mabouya s l o a n e i E l e u t h e r o d a c t y l u s a n t i l l e n s i s S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s * T y p h l o p s r i c h a r d i S t . Thomas * A l s o p h i s p o r t o r i c e n s i s Ameiva e x s u l Amphisbaena f e n e s t r a t a A n o l i s c r i s t a t e l l u s w i l e y a e E l e u t h e r o d a c t y l u s cochranae E l e u t h e r o d a c t y l u s l e n t u s * Geochelone c a r b o n a r i a Hemidact y l u s mabouia * Iguana i g u a n a Anolis p u l c h e l l u s Anolis s t r a t u l u s A r r h y t o n ex iguum E l e u t h e r o d a c t y l u s antillensis L e p t o d a c t y l u s a l b i l a b r i s * Mabuya mabouya s l o a n e i S p h a e r o d a c t y l u s macro l e p i s m a c r o l e p i s * T y p h l o p s r i c h a r d i S a l t I s l a n d * A1 s o p h i s p o r t o r i c e n s i s * H e m i d a c t y l u s mabouia Ameiva e x s u l Mabuya mabouya s l o a n e i A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s macro1 e p i s S a l t K e y * Ameiva e x s u l * Anolis c r i s t a t e l l u s w i l e y a e Sandy Cay (nea r Tor to l a ) Anolis c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Sandy S p i t Anolis cris t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Savanna I s l a n d * A l s o p h i s p o r t o r i c e n s i s * Anolis s t r a t u l u s Ameiva e x s u l * S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s * A n o l i s c r i s t a t e l l u s w i l e y a e Scrub I s l a n d Ameiva e x s u l An01 i s s t r a t u l u s Anolis c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Spiny But te S p h a e r o d a c t y l u s nicholsi n i c h o l s i S u r p r i s e Key A n o l i s c r i s t a t e l l u s w i l e y a e T y p h l o p s r i c h a r d i S p h a e r o d a c t y l u s n i c h o l s i t o w n s e n d i Tobago Ameiva e x s u l A n o l i s c r i s t a t e l l u s w i l e y a e Hemi d a c t y l u s mabouia S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Tor to l a Ameiva e x s u l * Amphisbaena f e n e s t r a t a Anolis c r i s t a t e l l u s w i l e y a e Anolis p u l c h e l l u s Anolis s t r a t u l u s * Anolis s p . ( g i a n t form) A r r h y t o n e x i guum E l e u t h e r o d a c t y l u s s chwar t z i * E p i c r a t e s m o n e n s i s * Geoche lone c a r b o n a r i a H e m i d a c t y l u s mabouia * Iguana i g u a n a L e p t o d a c t y l u s a l b i l a b r i s S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s E l e u t h e r o d a c t y l u s a n t i l l e n s i s T y p h l o p s r i c h a r d i E l e u t h e r o d a c t y l u s cochranae Turramote Key ( S p h a e r o d a c t y l u s nicholsi n i c h o l s i ) Vieques * A l s o p h i s p o r t o r i c e n s i s Ameiva e x s u l * A n o l i s c r i s t a t e l l u s w i l e y a e * A n o l i s c u v i e r i A n o l i s pu l chell u s A n o l i s s t r a t u l u s ~ u f o m a r i n u s ( introduced) E l e u t h e r o d a c t y l u s an t i l lensis * Hemidact y l u s mabouia L e p t o d a c t y l u s a l b i l a b r i s Mabuya mabouya s l o a n e i (now probably l o c a l l y e x t i n c t ) Rana c a t e s b e i a n a ( introduced) (J. E . Cooper, pers . comrn. S p h a e r o d a c t y l u s m a c r o l e p i s i n i g o i S p h a e r o d a c t y l u s nicholsi t o m s e n d i S p h a e r o d a c t y l u s roosevel ti V i l l a d e l Mar A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Virgin Gorda A l s o p h i s p o r t o r i c e n s i s * B u f o t u r p i s Ameiva e x s u l E l e u t h e r o d a c t y l u s a n t i l l e n s i s * Amphisbaena f e n e s t r a t a E l e u t h e r o d a c t ydus s c h w a r t z i A n o l i s c r i s t a t e l l u s w i l e y a e Mabu ya mabouia s l o a n e i A n o l i s p u l c h e l l u s S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s A n o l i s s t r a t u l u s S p h a e r o d a c t y l u s p a r t h e n o p i o n A r r h y ton ex iguum Typh l o p s r i c h a r d i Water I s l and Ameiva e x s u l * Geochel one c a r b o n a r i a * A n o l i s c r i s t a t e l l u s w i l e y a e * Hemidact y l u s mabouia * A n o l i s p u l c h e l l u s * Iguana i g u a n a * A n o l i s s t r a t u l u s * S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s Watson Rock S p h a e r o d a c t y l u s m a c r o l e p i s m a c r o l e p i s West Dog I s l and * * A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s m a c r o l e p i s macro1 e p i s West Seal Dog I s l and A n o l i s c r i s t a t e l l u s w i l e y a e S p h a e r o d a c t y l u s macro1 e p i s macro1 e p i s Appendix I V . Dis t r ibut ion of t h e scorpion Centruro ides n i t i d u s and the spider Gasteracantha t e t racan tha on the Puerto Rican Bank Cen t r u r o i d e s n i t i d u s Anegada Beef Island Big H a n s Loll ick Big Tobago Broken Jerusalem Caja de Muertos Cayo Diablo Cayo Norte Cooper Island Desecheo Eustat ia Fallen Jerusalem George Dog Great Dog Greater Camanoe Great Thatch Island Guana Is land Hicacos J o s t van Dyke L i t t l e Hans Lollick L i t t l e J o s t van Dyke L i t t l e Thatch Is land L i t t l e Tobago Magueyes Marina Cay Mosquito Island Necker Island Norman Island Palominos Peter Island Piiieros Prickly Pear Puerto Rico Ramos St . Croix St. John S t . Thomas S a l t Island Scrub Is land Tortola Virgin Gorda Gasteracan tha t e t racan tha Anegada Beef Island Big Hans Lollick Big Tobago Cayo Diablo Culebrita Desecheo Eusta t ia George Dog Ginger Is land Great Dog Greater Camanoe Great Thatch Island J o s t van Dyke L i t t l e Camanoe L i t t l e Hans Loll ick L i t t l e Thatch Island Mosquito Island Necker Island Norman Island Pifieros Puerto Rico S a l t Is land Tortola Virgin Gorda CATHERINEBURG, ST. JOHN r 20 - 74 54 53 4 9 0 - =.I- 46 . 60 4 5 4 2 CRUZ BAY, ST. JOHN 46 20 . 42 33 I 0 L m 42 35 CHARLOTTE AMALIE, ST. THOMAS 5 2 36 L _-', CULEBRA 28 28 - LC 28 24 C I I - .- I I m 0 RIO BLANCO UPPER. PR. 174 132 RIO P I E D R A S . PR. 67 74 20. 6') 77 61 59 5 8 0 MONA 4 8 3 0 Fig. 2. R a i n f a l l a t var ious l o c a l i t i e s on t h e Puerto Rican Bank, 1960-1967. Data from Climatological Data Puerto Rico and Virgin I s l a n d s , Vols. 6-12 (1960-1967). Numbers above histograms i n d i c a t e yea r ly t o t a l s . F i g . 3. Temperatures at Magueyes I s l a n d , P u e r t o Rico , 1960-1966. Upper l i n e r e p r e s e n t s mean d a i l y maxima, middle l i n e t h e monthly means, and lower l i n e t h e mean d a i l y minima. Data from same s o u r c e as t h a t o f F i g u r e 2. CRUZ BAY 5+ - -- - CHARLOTTE AMAL IE - - ALEX HAMILTON Fl ELD MAGUEYES RIO PIEDRAS GUINEO RESERVATION F i g . 4. Temperature a t va r i ous l o c a l i t i e s on t h e Pue r to Rican s h e l f du r ing 1964. Crux Bay, S t . John; C h a r l o t t e Arnalie, S t . Thomas; Alexander Hamilton F i e l d , S t . Cro ix ; Magueyes I s l a n d , Southwest P. R . ; Rio P i e d r a s , c o a s t a l P. R . ; Guineo Reserva t ion , upland P. R . Dot ted l i n e s i n d i c a t e m i s s ing d a t a , do t t h e August mean at Guineo Reservo i r . The upper and lower l i n e s f o r Rio P i ed ra s r e p r e s e n t monthly maxima and minima r e s p e c t i v e l y . Other symbols a s i n F igu re 3. Data from C l ima to log i ca l Data Pue r to Rico and V i rg in I s l a n d , Vol. 1 0 (1964 ) . M A R C H 18 M A R C H 19 I966 Fig . 5 . A i r and b lack bulb tempera tures on Cayo Ahogado, P . R . Broken l i n e s i n d i c a t e i n t e r v a l s of more t han 1 hour between measurements. Dots: b lack bulb temperatures 15 cm above t h e ground. T r i ang le s : a i r , 1 cm above ground. C i r c l e s : a i r , 15 cm above ground. Squares: a i r , 1 m above ground Fig. 6. Unshaded soil temperatures on Cayo Ahogado. Broken lines indicate intervals of more than one hour between measurements. Triangles: a t soil surface. Circles: 1 cm deep. Dots: 5 cm deep I . . . . . . . . . . . . . . . . . . . . 12 2 4 12 M A R C H I 8 M A R C H I S 1 9 6 6 I SHELTERED I OPEN I SHELTERED I OPEN I F i g . 8. Diagram-map of h y p o t h e t i c a l i s l a n d showing s p a t i a l r e l a t i o n - s h i p s o f numbered v e g e t a t i o n c a t e g o r i e s ( d e s c r i b e d i n t e x t ) t o one a n o t h e r and t o t h r e e env i ronmenta l pa ramete rs . Three imaginary s t r a i g h t l i n e s , whose t e r m i n i a r e show and l a b e l l e d , d i v i d e t h e i s l a n d i n t o two c o n d i t i o n s each o f wind exposure , wave exposure , and d i s t u r b a n c e . E l e v a t i o n i n c r e a s e s towards t h e c e n t e r . A s i s l a n d s i n c r e a s e i n a r e a and e l e v a t i o n , c o n c e n t r i c r i n g s a r e added from t h e c e n t e r , beg inn ing w i t h t h e most marg ina l r i n g n o t y e t p r e s e n t , t h u s p r o g r e s s i v e l y expanding t h e r i n g s a l r e a d y p r e s e n t toward t h e o u t s i d e . R e l a t i v e a r e a s a r e n o t t o s c a l e ; e . g . , most o f t h e a r e a o f a l a r g e , l i t t l e - d i s t u r b e d i s l a n d might b e covered by mois t f o r e s t ( 1 0 ) . WINDWARD EXPOSED LEEWARD SHELTERED CONDENSATION PRECIPITATION 2 4 1 1 2 Fig . 9 . V e r t i c a l s e c t i o n ac ros s a hypo the t i ca l i s l a n d showing s p a t i a l r e l a t i o n s h i p s of numbered vege ta t ion ca t egor i e s (desc r ibed i n t e x t ) t o one another , d i s t ance from t h e s e a , topography, e l e v a t i o n , wind d i r e c t i o n , and wave exposure. Not t o s c a l e .