ATOLL RESEARCH BULLETIN No. 145 MYITS ON THE VASCULAR FLORA AND TERRESTRIAL VERTEBRATES OF CAROLINE ATOLL SOUTHERN LINE ISLANDS by Roger B . Clapp and Fred C. S ib ley Issued by THE SMITHSONIAN INSTITUTION Washington, D. C . , U. S. A . February 16, 1971 Nake I. Caroline Atoll 0 112 I Colony N o u t i < o l M i l e Soot J Tern Colonies Sooty Tern Colonies Brothers Ilt. South I. Reef rep. to extend 1 mile from Southeast point 150:14' I?' M Figure 1. Map o f Caroline A t o l l . Modified from H. 0. char t 928. NOTES ON THE VASCULAR FLORA AND TERRESTRIAL VERTEBRATES OF CAROLINE ATOLL SOUTHERN LINE ISLANDS ' by Roger B. c lapp2 and Fred C. s ib l ey3 From 0900 on 17 June t o 0615 on 19 June 1965 Caroline Ato l l was v i s i t e d by a f i e l d pa r ty from t h e P a c i f i c Ocean Biologica l Survey Program (POBSP) of t h e Smithsonian I n s t i t u t i o n . The f i e l d pa r ty , l e d by Sibley, co l l ec ted and made observat ions on vascular p l a n t s , f i s h , r e p t i l e s , mammals, and b i r d s . A l l i s l a n d s with t h e exception of the nor thern two-thirds o f Nake were v i s i t e d . P r io r knowledge o f t h e b i o t a of Caroline Atol l i s very scan t , de r iv ing almost e n t i r e l y from t h e v i s i t s o f F. D . Bennett i n 1835, Devoy i n 1875, and t h e U.S.S. Hartford i n 1883. This paper summarizes e a r l i e r d a t a and presents recent POBSP observat ions on the f l o r a and t e r r e s t r i a l v e r t e b r a t e s , i den t i fy ing many of them f o r t h e f i r s t t ime. DESCRIPTION Caroline i s a low, densely vegetated, crescent-shaped c o r a l a t o l l s i t u a t e d between 09"55' and 10?01' south l a t i t u d e , and 150'14' and 150'13' west longitude. I t is about 125 n a u t i c a l mi les e a s t of Vostok Is land and 125 miles no r theas t of F l i n t I s land. The a t o l l i s 5.75 miles long on t h e north-south axis , and a t t a i n s a maximum breadth of 1.125 miles a t t h e south end. I ts a r e a i s ca. 942 ac res and i t s circumference around the outer r ee f i s about 13 m i l e s (Holden and Qualtrough, 1884; Maude, 1953) . The c e n t r a l lagoon has much l i v i n g co ra l , and c o r a l heads break t h e su r face . There a r e t h r e e l a r g e i s l ands , Nake and Long t o t h e nor th (conjoined on t h e e a s t ) , and South t o t h e south. Around t h e a t o l l r i m and within t h e lagoon a r e small i s l e t s , many o f which a r e unnamed (Figure 1 ) . A t low t i d e i n 1965 t h e r e were 15 i s l e t s separa ted by water. Dry, unvegetated, f l a t a reas o f co ra l rock d iv ide t h e i s l e t s , i nd ica t ing t h a t a t one time over 25 sepa ra te i s l e t s may have ex i s t ed . ~ ~~ ~~ ~ ~~~ ~ ~- 1. Paper No. 61, P a c i f i c Ocean Biological Survey Program, Smithsonian I n s t i t u t i o n , Washington, D. C. 2. P a c i f i c Ocean Biologica l Survey Program, Smithsonian I n s t i t u t i o n . 3. Point Reyes Bird Observatory, Bolinas, Ca l i fo rn ia . BRIEF HISTORY OF MAN'S ACTIVITIES ON CAROLINE ATOLL Caroline Atoll was discovered by Pedro Fernandez de Quiros on 21 February 1606 (Maude, 1959). The a t o l l was subsequently sighted o r v i s i t ed by par t ies from a number of passing ships' I t was v i s i t ed on 16 December 1795 by the Bri t ish sloop Providence, commanded by W . R . Broughton, who named the is land Caroline a f t e r the daughter of S i r P. Stephens, F i r s t Lord of the Br i t i sh Admiralty. In 1821 it was sighted by Captain Thornton of the English whaler Supply f o r whom it received the a l te rna te name Thornton (Bryan, 1942). It was v i s i ted 10 t o 13 October 1825 by Hiram Paulding on the U.S. schooner Dolphin, and i n 1828 by a Captain Stavers. On 23 April 1835 F. D. Bennett (1840) v i s i t ed the a t o l l from the whaler Tuscan. In 1875 Caroline was v i s i t e d by C . D. Voy, a na tura l i s t from California who collected molluscs (Pilsbry and Vannatta, 1905a, 1905b) and f i s h (Fowler, 1899, 1901). From 2 1 April through 9 May 1883 a par ty from the U.S.S. Hartford was there t o observe a t o t a l ecl ipse of t he sun (Holden, 1884). During the v i s i t observations and collections were made of plants (Trelease, 1884) and lepidoptera (Butler and Strecker, 1884), and very sketchy observations of t e r r e s t r i a l vertebrates and invertebrates 'were made by Dixon (1884). Archaeological remains found on Caroline indicate tha t the a t o l l was occupied, possibly by people from the Tuamotus (Emory, 1947), p r io r t o European exploration of the Pacif ic , but t he f i r s t recorded occupancy began i n 1846 when Collie and Lucett, a Br i t i sh firm, established a small nat ive agr icul tural experiment there (N.I.D., 1943). Between 1865 and 1872 Messrs. Brown and Brothers planted coconuts on the a t o l l and i n July 1868 there were 27 human occupants. In 1872 the island was leased t o Houlder Brothers and Company of London, and l a t e r , i n 1881, t o t h e i r manager, J. T. Arundel. Approximately 10,000 tons of guano were exported between 1873 and 1895. Coconut palms were planted during t h i s period and copra was harvested i n small quant i t ies (Bryan, 1942; N. I.D., 1943). Caroline was subsequently leased t o Messrs. S. R. Maxwell and Company Ltd., a New Zealand firm, and was worked continuously as a coconut plantation from 1916 u n t i l 1934 when the company fa i led . Exports during the l a t t e r par t of t h i s period amounted t o about 14 tons per annum. For a short time thereaf te r Caroline was worked,as a coconut plantation by the administrator f o r the company's a f f a i r s . By 1936 only a few Tahitian families were s t i l l occupying the a t o l l (N.I.D., 1943). The a t o l l was evidently seldom occupied, i f a t a l l , a f t e r 1 June 1943 when the occupation leases were cancelled and possession of the a t o l l reverted t o the Bri t ish Western High Pacif ic Commission (Maude, 1953). VEGETATION In 1825, Paulding (1831) noted tha t Caroline had "some t r ee s of a large size upon it and i n most places a thick growth of underwood" and fur ther remarked tha t "a boat load of pepper-grass and pursley, of which there was a great abundance" was obtained. He only mentions seeing one coconut t r e e which, i n l i gh t of Bennett's observations (see below), suggests tha t South Island was not v i s i ted . Nearly ten years l a t e r Bennett (1840) made more detai led observations of the vegetation. He recorded ten flowering plants and a fern, in t ro- duced three other species, and re la ted tha t - Cocos were found only i n a grove on the northeast s ide of South Island--a grove tha t covered about one-fif th of the land area of t h a t island. Bennett s ta ted t h a t the a t o l l was "covered with verdure" and t h a t "the in t e r io r of the is land [was] a surface of sand, mingled with coral debris as well as with decayed vegetable and animal matters, which give it increasing f e r t i l i t y " . He a l so mentioned t r ee s "attaining the height of twenty feet" which may indicate tha t Cordia o r Pisonia groves o r both covered a more extensive area i n the l a s t century. Bennett s ta ted tha t "the woodlands are chief ly composed of two species of Tournefortia" which we can only in te rpre t as a reference t o Cordia as well as Tournefortia. We have not been able t o determine the present disposit ion of Bennett 's plant collection, i f indeed i t s t i l l e x i s t s . The only reasonably thorough collection of plants was made by W.S. Dixon during the v i s i t of the U.S.S. Hartford. Many of the plant species collected or observed by Dixon were probably introduced during the e a r l i e r occupation of the is land. Dixon's collections and obser- vations (27 or 28 flowering plants , a fern, an alga, and a fungus) were subsequently reported by Trelease (1884). A l l p lants , with the exception of Fleurya ruderal is , were collected on South Island. Below i s a short summary of the vegetation of each large is land and of the i s l e t groups as observed by the POBSP i n 1965. South Island. Old Cocos groves cover most of South Island. Interspersed - with these groves are thickets of Morinda tha t are often associated with Ipomoea tuba. In some open areas ivhereocos have died o r f a l l en the - grass Lepturus repens forms a nearly closed stand with Ipomoea. A Suriana-Le turus zone forms a fringing association around the island. Suriana fE- orms a dense continuous border of shrubs on the north s ide bordering the lagoon (Figure 2). On the other sides the Suriana shrubs are t a l l e r ( to 2 m), l e s s compact, and more scat tered. Patches of Lepturus are scat tered here and there and often extend well outside and beyond the Suriana zone towards the high-tide l i ne . Individual t r ee s of Pisonia grandis and Cordia subcordata were likewise scat tered over the island. Nake Island. On Nake, which had been planted t o - Cocos l i k e South Island, groves extend the en t i r e length of the island. The greater robustness of these - Cocos groves, the occurrence of Psilotum, and the more frequent occurrence of - Tacca, suggest t ha t Nake received more precipi ta t ion than other portions of the a t o l l . Associations of Pandanus, Morinda and Tournefortia occur i n open areas of the i n t e r io r and along the edge of the - Cocos stands. Along the northeast s ide an almost continuous stand of Tournefortia borders the area between the - Cocos groves and the open sandy beach with i t s scattered clumps of Lepturus and the ubiquitous Boerhavia repens. Some older Tournefortia t rees were nearly 3 meters high. Tacca was found in scat tered groups i n damp muck areas under the C o c o s v e s . The only Tribulus observed on the e n t i r e a t o l l was f o a n an open sandy area among Tournefortia shrubs on the south end of the island. Long Island. Clumps of Morinda and Cordia occur on the north end. Pisonia, Cordia and Suriana were a l so observed. On both s ides of the island Tournefortia forms a f r inge with open areas supporting associations of Lepturus, Boerhavia, and Portulaca (Figure 3 ) . Windward I s l e t s . Small Cordia groves are present on most of these small eastern i s l e t s . Brothers I s l e t has a few - Cocos t rees . Suriana, forming a dense stand with Tournefortia, was found ( to 3 m i n height) on the i s l e t jus t south of Arundel I s l e t . Tournefortia i s a lso an important component on the other windward i s l e t s . Leeward I s l e t s . The vegetation on these i s l e t s is much sparser than on those on the windward side of the a t o l l . Pandanus occurs on the three small i s l e t s south on Nake Island. Further south l i e s an i s l e t with a few Cocos t rees and Pisonia. The other i s l e t s on the south have Cordia and G e f o r t i a with L e p t y ? , Fleurya, and Heliotro ium. The Fleurya occupies small sand- f i l l e niches i n the expose 77- coral rubble while the Heliotropium is found i n sand on the lagoon s ide of the i s l e t s . The general aspect of the vegetation indicated a lengthy dry spe l l p r io r t o our v i s i t . VASCULAR FLORA OF CAROLINE ATOLL Vascular plants were collected by C. R. Long (POBSP) on 17 and 18 June. Herbarium specimens w i l l be deposited i n the herbarium of the University of Hawaii and some duplicates i n the herbaria of the United States National Museum and the Bernice P. Bishop Museum. In the following list col lect ion numbers are those of Long's. Species not previously known t o occur on the a t o l l are marked with an as te r i sk . Psilotaceae *Psiloturn nudum (L.) Beauv. Found only on Nake I . , common on wet base of Cocos, Long 3233. Polypodiaceae Polypodium scolopendria Burm. f . Collected by Dixon and recorded by Bennett (as Polypodium phymatodes L ) . Ground cover under Cocos fores t s on Nake I . , Long 3244; under scat tered Cocos north e n d m o n g I . , 3250; South 1 x 2 2 8 7 . - Apparentlythriving even under very dr-nditions. Pandanaceae Pandanus tector ius Park. An unidentified Pandanus was reported by Bennett and Trelease. Tree 2.5 m high a t west edge of second i s l e t south of Nake I . , Long 3227. Also observed on Nake I . Gramineae Eleusine indica (L.) Gaertn. Collected by Dixon. Not found by the POBSP. Eragrostis t ene l la (Link) Beauv. Collected by Dixon and reported by Trelease as E. plumosa Lk. Not - found by the POBSP. Lepturus repens (Forst. f . ) R. B r . Collected by Dixon. Tufts t o 1.5 dm high i n coral sand, on second i s l e t south- of Long I . , Long 3211; i s l e i northeast of ~ b u t h I . , 3221; common growing i n coral sand several meters above lagoon, - Nake I., - 3236; exposed s i t e i n sand on eas t windward s ide of Nake I . , 3238; exposed s i t e in sand, Long I . , - 3247; near lagoon shore of west s ide of fourth i s l e t north of Bird I . , 3259; numerous - clumps under Suriana on South I., 3286. - Digi tar ia sp. Collected by Dixon and recorded by Trelease as Panicum (Digitaria) marginata Lk.? C. R. Long who examined Dixon's specimen believes tha t i t is a Digi tar ia which may be ident ical t o - 3235. Bromeliaceae Ananas comosa L . Collected by Dixon who found it cult ivated on Caroline. Not found by the POB&. Palmae Cocos nucifera L . Reported as "cocoa-nut t rees" by Bennett and ident i f ied as above by Dixon. Dry groves of South I . , Long 3285. Extensive stands cover Nake and South I s . ; a scattered number on north portion of Long I . Liliaceae Crinum sp. An unidentified l i l y collected by Dixon and reported by Trelease was probably i n t h i s genus. Taccaceae Tacca leontopetaloides (L.) 0. Ktze. Introduced by Bennett but not found by Dixon. Occasionally i n moist muck of South I . , -- Long 3213; i n f r u i t on South I . , 3219; common under Cocos fores t of Nake I . , - 3234. Numerous patches found i n m u c k m h e south en= Nake I . Moraceae Ficus car ica L. Collected by Not found by Fleurya ruderal is . Reported by Bennett and collected by Dixon. Common in shady areas of South I . , Long 3215; scat tered on an exposed s i t e i n coral rubble and sand, second i s l e t south of Nake I . (west s ide) , 3229; under shade of Cocos and Pisonia on north s ide of Long I., - - 3253. Many seedlings observed on Long I. - Dixon. An introduction cul t ivated for i t s f r u i t . the POBSP. Urticaceae (Forst. f.'l Gaud. ex Wedd. Chenopodiaceae Boussingaultia g rac i l i s Miers forma pseudo-basseloides Hauman Collected by Dixon and reported by ~ r e m b a s e l o i d e s H. B. K . Treleasets comment t ha t the specimen ccllected by Dixon was a "vine climbing over portico" suggests tha t it was introduced by res idents of Caroline. Not found by the POBSP. Nyctaginaceae Boerhavia repens L . Reported by Bennett as B. h i r su t a and col lected (as Boerhaavia, sp.?) by Dixon. Light purple-flowers, second i s l e t south of Long I . , Long 3210; stems t o 0.6 m long, large cori,aceous leaves, red stems, i s l e t northeast of South I . , 3324; Nake I . , 3239; stems t o 0.5 - m long, rooting a t nodes, ~ a k x , 3225; north end of Long I . , 3252;-fourth i s l e t north of Bird 1 . 7 6 2 ; - i n shade, south I . , 3289, 3291. -- Pisonia grandis R. B r . Collected by Dixon. Tree about 4 m high, north shore of South I . , Lon 3280. A small grove observed on the north end of Long I . 2- Portulacaceae Portulaca lutea Sol. Reported by Bennett. Trelease s t a t ed tha t Dixon recomized two - var ie t ies bf Portulaca but ne i ther was collected. Stems clumped, flowers yellow, i s l e t northeast of South I. , Long 3223; clumps -- 1.5 dm high, common i n open coral and rubble, second i s l e t south of Nake I. , 3231; common on Nake I . , 3237; common i n gravel above - - lagoon shore on north end of Long I . , 3255; fourth i s l e t north of - Bird I. , 3257; common i n exposed area on South I . , 3292. - - Cruciferae Lepidium bidentatum Mont. Collected by Dixon as L. i sc idiun Forst. Also reported by Bennett as a "Lepidium of 1uxuFiant -It growt . Not found by the POBSP. Leguminosae Inocarpus fagiferus (Park.) Fosberg Introduced by Bennett but not found subsequently. Zygophyl laceae *Tribulus c is toides L. Stems t o 0.8 m long i n an open sandy area among Tournefortia shrubs on Long I . , Long 3245. Not seen elsewhere on the a t o l l . Surianaceae Suriana maritima L. Collected by Dixon. Shrub t o 1 .8 m high on east edge of i s l e t northeast of South I . , Long 3220. - Euphorbiaceae Euphorbia p i l u l i f e r a L. Collected by Dixon. Not found by the POBSP. Phyllanthus amarus Schum. and Thonn. Collected by Dixon and recorded by Trelease as - P. n i ru r i L . , Herb t o 4 dm, common on the north s ide of South I . , Long 3283. Malvaceae Sida fa l lax Walp. Collected by Dixon who only found one specimen. Not found by the - POBSP. Guttiferae Calophyllum ino hyllum L. +Collected y Dlxon but not found by the POBSP. Caricaceae Carica papaya L. Collected by Dixon. An introduction not found by the POBSP. Cucurbitaceae Cucurbita L . "Recognized i n cult ivation" by Dixon but not found by the POBSP. Convolvulaceae *Ipomoea pes-caprae ssp. b ras i l i ens i s (L.) Van Ooststr . Stems t o 7 m long, i n f r u i t , near copra shed, north shore, South I . , Long 3281. &Iy one seen bn the a t o l l . Ipomoea batatas L . Introduced by Bennett but not found subsequently. *Ipomoea tuba (Schlecht.) G. Don Trai l ine vine. white flowers. stems t o 6 m lone. common on South " I . , Long 32281 Nake I . , 32421 t r a i l i n g on Tour&fortia a t north end of Long I . , 3251; stems t o 25 m climbing over Morinda and - Cocas on South I . , 3293. - - >. - Boraginaceae Cordia subcordata Lam. Collected by Dixon. Tree t o 4 m near lagoon, South I . , Long 3213; -- t r ee t o 3 m high i n i n t e r io r of i s l e t i n coral rubble about 15 meters above high t i d e l ine , west s ide of second i s l e t south of Nake I . , 3228; t r e e t o 4.5 m high with orange flowers, common on - i n t e r io r of north end of Long I . , 3246; fourth i s l e t north of - Bird I., - 3261; t r e e t o 4 m a t edge of water along lagoon, north shore of South I . , 3261. - Heliotropium anomalum H. and A. Recorded (as Heliotropium curassavicum) by Bennett and collected by Dixon. In gravel of outer beach of i s l e t northeast of South I., Long - 3222; common i n clumps t o 1 .2 dm high in exposed s i t e i n coral =el on lagoon s ide of second i s l e t south of Nake I. (west side), 3240; i n gravel of lagoon shore, Long I . , 3248; fourth i s l e t north - - of Bird I., - 3256; clumps t o 2.8 dm high on coral gravel under Suriana on the southwest s ide of South I . , 3288. Tournefortia argentea L . f . Probably seen by Bennett, and collected by Dixon. Small t ree , with white fiowers, i . 5 m high, edge of lagoon; South I., Lon 3216; edge of i s l e t northeast of South I. , - 3226; shrub 3 m d , x v e high-tide l ine , Nake I . , 3241; Long I . , - 3249; common, fourth i s l e t north of Bird I ., 3258. - - Scrophulariaceae Russelia equisetiformis Schlecht . Collected by Dixon as R. juncea Zucc. Re lease noted tha t it had been probably introducFd. Not found by the POBSP. Rubiaceae Morinda c i t r i f o l i a L. Reported by Bennett and collected by Dixon. Small t ree , 2 m high ~ & t h I., iong 3214; young plant, 6- dm high, South I., 3217; shrub t o 2.5 m, Nake I . , - 3232; common a t edge of Pisonia fores t north end of Long I . , - 3254; small t r e e t o 3 m f o r m m n s e thickets , central area of South I . , - 3282. TERRESTRIAL VERTEBRATES OTHER THAN BIRDS "Small lizards1' were reported i n 1825 by Paulding (1831) but ten years l a t e r Bennett s ta ted tha t he had seen no "lizards o r other land amphibia." Dixon (1884) reported three species of l izards but did not ident i fy them. Dixon also reported t u r t l e s (Chelonia mydas?) - but noted they were not numerous. Three species of l izards were found on the a t o l l by the POBSP and specimens were obtained of each: one Black Skink (Emoia -nigra, USNM 158358), two Polynesian Geckos (Gehyra oceanica. USNM 158353-354), and three Mourning Geckos (Lepidodactylus lugubris, USNM 158355-357). No t u r t l e s were seen. Domestic pigs were introduced by Captain Stavers i n 1828 (Bryan, 1942) but none were present when Bennett v i s i t ed the a t o l l seven years l a t e r . In 1848 several native families with 'p igs , fowls, turkey, etc." were transported t o Caroline by Edward Lucett (1851) and i n 1868 the 27 persons l iving on the is land were ra i s ing stock, pigs, and poultry (Bryan, 1942). No livestock were reported i n 1883 by Dixon, nor were any found on the islands by the POBSP. Rats were seen by both Bennett and Dixon. Bennett s ta ted tha t the r a t s "were of a red-brown color," while Dixon noted tha t "the brown r a t . . . i s not numerous" and tha t " their nests were made i n the cocoa-nut trees, jus t a t the base of the fronds." The POBSP saw Polynesian Rats (Rattus exulans) on South Island and collected two (USNM 361450-451). USNM 361450 was a juvenile male weighing 19.3 grams and 361451 was a female weighing 53 grams. Measurements ( in mm) of the t o t a l length, t a i l , hind foot, and ea r f o r the two specimens were, respectively, 206, 106, 25, 15 and 270, 173, 30, 17. Rats were not common and were observed only on South. OBSERVATIONS OF BIRDS Few of the birds seen by Bennett and Dixon were iden t i f ied t o species but some were described i n enough d e t a i l t o allow an ident i f icat ion. Bennett (1840) reported seven species: "a tree-nesting booby" (=Sula -- sula), "frigatebirds" (Fregata sp .?) , "a coot" ( 1 , wcurlews" Y(=Numenius t ah i t i ens i s ) , "a specles of Totanus, s imi la r t o t ha t we found a t Raitea, with the exception tha t i t s legs a r e lemon-color, while i n the Raitean species they were blue" (perhaps Heteroscelus incanum, while the b i rd seen a t Raitea may have been Pluvial is dominica), "a great number of small pigeons, with white head and neck, and the r e s t of t h e i r plumage a r i ch brown color" (probably Anous - t enui ros t r i s but possibly - A. stolidus), and "small white terns" (=Gygis alba). Dixon (1884) reported 12 species but spec i f ic iden t i f ica t ion is reasonably cer ta in for only four: "ploverg1 (P. dominica), @tcurlewlf (N. tah i t iens i s ) , a heron tha t occurred i n "two var ie t ies , brown and wKitet' (=Demigretta sacra) , and "an all-white ternf1 (=G. - - alba) . He also reported v f s n i p e ~ e t e r o s c e l u s o r Arenaria?), two species of "seagull" ( ? "the noddy" (Anous sp. ?), the "Frigate birdqf (Fregata sp.) a "Gannet" and a " ~ o o b ~ ~ o b a b l ~ -- Sula su l a and - Sula sp.?); he reported tha t a colleague had heard "the notes of a singing bird" (? ) , Arundel (1890) s ta ted tha t "a pigeonff occurred on Caroline. This may have referred t o Ducula but equally l ike ly t o - Anous. Thus, although a f a i r l y wide variety of birds had been reported p r io r t o the POBSP v i s i t , spec i f ic ident i f icat ions were reasonably cer ta in for only f ive species: Red-footed Booby, Golden Plover, Bris t le- thighed Curlew, Reef Heron, and White Tern. In the following species accounts the numbers i n parentheses follow- ing the species name are an estimate of the t o t a l number of f lying birds , including breeding adults, nonbreeding adults, subadults and juveniles. Following t h i s f igure i s another which gives the>estimated number of breeding birds . These estimates are not very accurate since the brevity of the v i s i t and the large number of i s l e t s v i s i t ed precluded detailed census work. We present them because we f e e l t ha t such estimates, although par t ly subjective, show re l a t i ve abundance of the various species b e t t e r than such words as "numeroust1, "common", o r "scarce". Annotated L i s t BLUE-FACED BOOBY (ca - 10--at l e a s t 8 breeding birds) - Sula dactylat ra POBSP personnel found two nests , one containing two eggs, the other a nest l ing, on the eas t s ide of Nake Island along the ocean beach. Navy personnel reported two other nests with eggs from the same area. BROWN BOOBY (ca - 15 f 10% -- a t l ea s t 8 breeding birds) - Sula leucogaster Three nests, two with eggs and one with a nest l ing, were found on Nake Island. Five t o e ight adults were seen roosting on emergent portions of the coral reef along the southeast passage between South Island and the i s l e t south of Arundel I s l e t . RED-FOOTED BOOBY (5,000 f 25%--4,000 f 25% breeding birds) -- Sula su l a Red-footed Boobies were found nesting on almost a l l islands except South. Nests were found on a wide var ie ty of plants (Cordia, Morinda, Pisonia, and Tournefortia) and contained eggs and young, with the l a t t e r ranging i n s i ze from recently hatched young t o near-fledging juveniles. Several other nests were found tha t had been recently l ined with fresh Pisonia leaves, suggesting t h a t some females had not yet la id . In l a t e April, 1835 (Bennett, 1840) Red-footed Boobies were building nests o r hatching eggs ( i . e . , incubating). No young were seen and a l l eggs examined were heavily incubated. Specimens: 3dd, 299, 18 June 1965: USNM 495106, d l e f t t e s t i s 10 x 4 mm, weight 726 g; USNM 495108, &? t e s t e s 14 mm, w t . 692 g; USNM 495109, d t e s t e s 14 x 7 mm, w t . 635 g; USNM 495105, 9, ovary 10 mm, granular, w t . 790 g; USNM 495107, 9 , ovary 20 x 10 mm, w t . 837 g; (USNM 495105 with a nestl ing, and 495106 and 495107 were collected from eggs). GREAT FRIGATEBIRD (10,000 f 25%--8,000 f 25% breeding Fregata minor birds) Great Frigatebirds were found nesting on almost a l l islands. Both eggs and young were present. Nests are found i n the same habi ta t u t i l i zed by Red-footed Boobies. Specimens: 2 99, both collected from eggs, 18 June 1965: USNM 495092 ovary 18 x 10 mm, lg . ovum 4 x 4 mm, w t . 921 g; USNM 495093, lg . ovum 3 mm, w t . 1200 g. LESSER FRIGATEBIRD (1,000 * lo%, 400 10% breeding birds) Fregata a r i e l - Lesser Frigatebirds nested only near the north end of Long Island (Figure 1) where a small colony of ca 400 birds had constructed nests i n low Morinda bushes and i n small ~ o r x a t rees , both of which were much overgrownby Ipomoea - tuba. Only eggs were found i n t he nests, but f lying immatures, presumably birds from a previous breeding season, were noted. Other f r igatebirds were seen displaying and building nests . I GOLDEN PLOVER (30 f 10%) Pluvial is dominica ! Golden Plovers, l i ke other shorebirds, were scarce but generally dis t r ibuted throughout the coral r ee f s . They appeared, l i k e other shorebirds, t o be somewhat more abundant along the outer perimeter of I the a t o l l . i Specimens: 18 June 1965: USNM 495722, d, t e s t e s 3 x 2mm, w t . 113 g. BRISTLE-THIGHED CURLEW (20 f 10%) I WANDERING TATTLER (70 f 10%) Numenius tah i t iens i s Heteroscelus incanum 1 Specimens: 3 dd, 18 June 1965: USNM 495726, t e s t e s 2 mm, w t . 102 g; USNM 495727, l e f t t e s t i s 3 x 2 mm, w t . 101 g; USNM 495728, t es tes 3 x 2 mm, w t . 121 g. I ! RUDDY TURNSTONE (ca - 5) REEF HERON (40 f 25%) Arenaria interpres Demigretta sacra I Most Reef Herons were seen foraging singly around t h e reefs but appeared more common along the i n t e r i o r lagoon. No nes t s were found ~ but the s i ze of the gonads of one specimen (USNM 495303) suggests t h a t the species may breed there. Of ten different individuals tabulated on 18 June, ha l f were white morph, ha l f dark morph. No mottled individuals were seen. Specimens: W , 19, 17 June 1965; Id, 18 June 1965: USNM 495301, d, t e s t e s 5 x 3 mm, w t . 522 g; USNM 495302, d, l e f t t e s t i s 6 x 4 mm, w t . I 540 g; USNM 495303, 0 , lg . ovum 10 mm, w t . 541 g; USNM 498280, d(ske1eton). SOOTY TERN (ca - 500,000 f 25%--ca 400,000 * breeding birds) Sterna fuscata Sooty Tern colonies were found on a number of the i s l e t s and several geographically d i sc re te colonies were found on the same i s l e t . In one instance colonies showed a discrete but small difference i n t h e i r breeding cycles on the same island (Table 1) . Most colonies contained incubated eggs t o week-old chicks, indicating t h a t peak eggs laying had occurred 2 t o 5 weeks e a r l i e r (mid-late May). Table 1. Sooty Tern Colonies on Caroline Atoll Approximate Number of Location of Colony Breeding Birds* Breeding Status Three groups of i s l e t s on west s ide of a t o l l jus t south of Nake I . South half of Long I. (3 colonies) I s l e t south of Arundel I s l e t (4 main colonies) Eggs and small chicks Only downy young Eggs t o week-old chicks Only eggs, most s l i gh t ly incubated Eggs t o week-old chicks (ca 20,000 eggs andT0,OOO nestl ings) Eggs t o week-old chicks *Most estimates determined by intensive banding o r by estimating nesting density and colony area. On most islands and on the i s l e t south of Arundel, nests were located i n the underbrush under stands of Tournefortia o r other emergent vegetation o r were i n more open areas bordering such stands (Figure 5). Considerable predation on eggs and nest l ings by the coconut crab (Birgus la t ro) was noted i n the colonies on the i s l e t south of Arundel. - Specimens: 1 d, 4 99, 17 June 1965: USNM 495481, d, rt. t e s t i s 7 x 5 mm, w t . 163 g; USNM 495479, 9 , ovary 11 x 5 mm, l g . ovum 2 x 2 mm, w t . 138 g; USNM 495480, 9 , ovary 10 mm, l g . ovum 1 mm, w t . 167 g; USNM 495482, 0 , ovary 10 x 7 mm, w t . 166 g; USNM 495483, 9, ovary 10 x 7 mm, ova granular, w t . 159 g. BROWN NODDY (1,000 f 25%--800 f 25% breeding birds) - Anous s to l idus Nests contained both eggs and young. Specimen: 17 June 1965: USNM 495562, d, t e s t i s 12 x 5 mm, w t . 150 g. BLACK NODDY (7,000 Black Noddies examined contained f 25%, 5,000 f 25% breeding birds) Anous tenui ros t r i s were found nest ing on most is lands. The few nests eggs or young. WHITE TERN (4,000 t 25% -- several thousand breeding birds) Gygis alba - White Terns were found breeding on most is lands. About ha l f of the breeding birds were with eggs, and half with young. Specimen: 18 June 1965: USNM 495608, 0 , l a rges t ovum 1.5 mm, w t . 100 g. BLUE-GRAY NODDY (ca - 5) Procelsterna cerulea Several Blue-gray Noddies were seen f ly ing over the cen t ra l lagoon and one of these was collected. No birds were seen on the ground and no nests were found. Specimen: 18 June 1965: USNM 495540, 0 , ovary 7 x 9 mm, l g . ovum 2 mm, w t . 54.1 g ( in heavy body molt). SUMMARY Observations and collections of the f l o ra and vertebrate fauna made by the Pacif ic Ocean Biological Survey Program i n June 1965 are reported herein. Twenty species of plants were collected includine 18 flowerine plants, a fern, and a Gilotum. Of these the p s i l o t i (Psilotum nldum) and three flowering plants (Tribulus c is toides , Ipomoea pes-caprae ssp. b ras i l i ens i s , Ipomoea tuba) had not been previously reported from the - a t o l l . Five other species were collected for the f i r s t time (Pandanus tector ius , Cocos nucifera, Tacca leontopetaloides, Boerhavia repens, Portulaca lu tea) . Many other species previously recorded from Caroline were not f- Most of these were introduced species (e.g., Carica papaya, Curcurbita E, Ficus carica) which probably did not survive the r igors of existence on the a t o l l . Three species of l i za rds were collected and ident i f ied (Emoia -nigra, Gehyra oceanica, and Lepidodactylus lugubris), none of which had been previously reported from the a t o l l but a l l of which are widespread in Polynesia. ~ b l ~ n e s i a n Rats (Rattus exulans), which had not been pre- viously ident i f ied t o species, were a l so collected. Fifteen species of birds were recorded. Four were migrant shorebirds (Golden Plover, Bristle-thighed Curlew, Wandering Tat t le r , Ruddy Turnstone) tha t occur commonly i n the central Pacif ic . Reef Herons possibly breed on Caroline but may have wandered t o the is land from other breeding s ta t ions i n the area. The remaining ten species are a l l seabirds tha t breed i n the cen t ra l Pacific. Of these, a l l were found breeding except the Blue-gray Noddy which i s apparently only a v i s i t o r t o the a t o l l . Red-footed Boobies, Great and Lesser Frigatebirds, Sooty Terns, Brown and Black Noddies were a l l common t o abundant, but Blue- faced and Brown Boobies were few i n number. ACKNOWLEDGEMENTS We are par t icu la r ly indebted t o C. R. Long who did a preliminary d r a f t of the vegetation section of t h i s account. We a l so thank the other members of the f i e l d party who contributed data for t h i s paper: Robert R. Fleet, Lawrence N. Huber, Dennis L . Stadel, and Robert S. Standen. Hugh H. I l t i s , Curator of the Herbarium of the University of Wisconsin, aided Long i n examining Dixon's botanical collection. The l a t e Doris M. Cochran ident i f ied the r e p t i l e s and Ralph D. Kirkpatrick made helpful comments on the mammals. We a l so thank Patrick J. Gould, C . Douglas Hackman, George E. Watson, and Paul W. Woodward who read the manuscript and made helpful suggestions. Logistic support was furnished by the United States Navy. LITERATURE CITED Arundel, J . T. 1890. The Phoenix Group and other islands of the Pacific. [Read before the Geographical Society of the Pacif ic ... San Francisco 3 March 1885 and reprinted i n the New Zealand Herald, Auckland, 5 and 12 July 18901. Bennett, F. D. 1840. Narrative of a whaling voyage around the globe from the year 1833 t o 1836... Vol. 1. Richard Bentley, London, v i i + 402 p. Bryan, E. H. , Jr. 1942. American Polynesia and the Hawaiian Chain. Tongg Publ. Co., Honolulu, 253 p. Butler, A. G . and H. Strecker. 1884. Memorandum of the bu t t e r f l i e s , e tc . of Caroline Island, i n Report of the operations of the American Expedition t o observe'the t o t a l ecl ipse 1883, May 6 a t Caroline Island, South Pacif ic Ocean. Nat. Acad. Sci. , Mem. No. 2 : 92-96. Dixon, W. S. 1884. Notes on the zoology of Caroline Island, Report of the operations of the American Expedition to . . . Caroline Island.. . Nat. Acad. Sci. , Mem. No. 2: 90-92. Emory, K . P. 1947. Tuamotuan rel igious s t ructures and ceremonies Bernice P. Bishop Mus. Bull. 191: 102 p. Fowler, H. W. 1899. Observations on f ishes from the Caroline Islands. Proc. Acad. Nat. Sc i . , Phila. vol. 51: 482-496. ---------- 1901. Fishes from Caroline Island. Proc. Acad. Nat. Sci . , Phila. vol. 53: 324-326. Holden, E . S. 1884. Journey from New York t o Caroline Island and return, i n Report of the...American Expedition to . ..Caroline Island.. . Nat. - Acad. Sci., Mem. No. 2: 16-20. Holden, E . S. and E. F . Qualtrough. 1884. Description of the island, - i n Report of the...American Expedition to...Caroline Island.. . Nat. Acad. Sci., Mem. No. 2: 22-26. Lucett, E . 1851. Rovings i n the Pacific from 1837 t o 1849... by a merchant.. . Vol. 11. Longman, Brown, Green, and Longmans, London, x i + 371 p. Maude, H. E . 1953. The Br i t i sh Central Pacif ic Islands: a report on land class i f icat ion and u t i l i za t ion . Proc. 7th Pacif ic Science Congress 6: 89-97. ---------- 1959. Spanish discoveries i n t he central Pacif ic . Jour. Polyn. SOC., 68: 284-326. N.I.D. [Great Britain, Naval Intell igence Division.] 1943. Pacif ic Islands, vol. 11. Eastern Pacific, H.M. Stationery Office, London, xvi + 739 p. Paulding, H. 1831. Journal of a cruise of t he United States Schooner Dolphin ... G . & C. & H. Carv i l l , New York, i v + 258 p. Pilsbry, H. A. and E . G. Vanatta. 1905a. Mollusca of F l in t and Caroline Islands, i n the central Pacif ic . Proc. Acad. Nat. Sci . , Phila., V O ~ . 57: 291-293. ---------- 1905b. On some Pac i f ic Cerithiidae. Proc. Acad. Nat. Sci., Phila., vol. 57: 787-789. Trelease, W . 1884. Botany of Caroline Island, - i n Report ... of the American Expedition t o ... Caroline Island.. . Nat. Acad. Sci. , Mem. NO. 2: 87-90. Figure 2 . North s ide of South Island on lagoon. Note thick fringing stand of Suriana along high-water l i ne . An occasional Pisonia or Cordia t r e e i s found between the Suriana fringe and the Cocos fores t . - Figure 3 . East s ide of Long I.sland with ~ o u r n e f o r t i a fr inge vegetation and scattered Suriana shrubs. P a t c h e s ~ e p t u r u s , Boerhavia, Portulaca association in foreground, Cocas t o l e f t . Figure 4. North portion of Long Island as seen from the South Point of I Nake Island. In the middle of Long Island are groves of I Cordia and Pisonia with a dense fringing cover of Tournefortia Figure 5 . Sooty Tern colony among and under dense vegetation on Bird I s l e t .