ATOLL RESEARCH BULLETIN 
NO. 182 
THE MURINE RODENTS RATTUS RATTUS,  EXULANS, 
AND NORVEGICUS AS AVIAN PREDATORS 
by F. I. Norman 
Issued by 
THE SMITHSONIAN INSTITUTION 
Washington, D.C., U.S.A. 
January 15,1975 
Contents 
Introduction 
References to Predation by Rats 
Apterygiformes 
Procellariiformes 
Pelicaniformes 
Ciconiiformes 
Ans erif ormes 
Gallif ormes 
Charadriiformes 
Columbiformes 
Psittaciformes 
Passeriformes 
lliscussion 
References 
Page 
1 
3 
3 
3 
4 
4 
THE MURINE RODENTS RATTUS RATTUS, EXULANS, AND NORVEGICUS 
AS AVIAN PREDATORS 
1 / by F. I. Norman- 
INTRODUCTION 
Few mammals have adventitiously accompanied man around 
the world more than members of the Murinae and of these, the 
most ubiquitous must surely be the Rattus group. Three species, 
-- 
R. rattus Linn., R. norvegicus Berkenhout, and R. exulans 
T~eale),have been h~storically associated with-man, and their 
present distribution reflects such associations. Thus although 
R. exulans is generally distributed through the Pacific region, 
- 
R. rattus and norvegicus are almost worldwide in distribution, 
- 
having originated presumably in Asia Minor, as did exulans 
(walker 1964.). All have invaded, with man's assistance, 
habitats which previously did not include them, and they have 
developed varying degrees of commensalism with man. Neither 
rattus nor norvegicus has entered antarctic ecosystems, but 
-- 
Law and Burstall (1956) recorded their presence on subantarctic 
Macquarie Island. Kenyon (1961) and Schiller (1956), however, 
have shown that norvegicus has become established in the arctic 
where localised populations are dependent on refuse as a food 
source during the winter. 
More frequently, reports bave been made of the over-running 
of islands by these alien rats. Tristan da Cunha is one such 
example (Elliott 1957; Holdgate 1960), and Dampier found rattus 
to be common on Ascension Island in 1701 though presently 
norvegicus is more widespread there (nuffey 1964). Rattus spp., 
- 
and - Mus musculus Linn., are present on some of the Galapagos 
islands ( A b s a l .  1965). In the Pacific, an influx of ratitus 
occurred during the Second World War (~ohnson 1945; Marshall 
1955), and these may have di-splaced exulans, a prior introduction 
-- (Morrison 1954). The rats, once introduced into areas of abun- 
dant food and no extreme of climate, may cease commensalism and 
exist independently of man. This may occur more readily in 
disturbed habitats where -- rattus generally predominates, perhaps 
because of i-ts wider range of food acceptance (e.g., Fall, 
Medina, and Jackson 1971 ) . 
The diet of these species, and of the Rattus group as a 
I'Arthur Rylah Institute for Environmental Research, 123 Brown 
St., Heidelberg. Victoria. 3084. 
(Manuscript received April 1972--Ed.) 
whole, tends to be of an herbivorous nature. However rattus, 
norvegicus and exulans have generally devel-oped an omnivorous 
- 
diet which has ultimately led to active predation and even 
cannibalism (e. g., Bailey and Sorensen 1962; Murphy 1936; 
Stei.niger 19148; Troughton 1962). 
Of especial concern to conservationists have been the 
persistent reports that the introduced rats were avian predators 
It is the purpose of this paper to present and briefly review 
such statements. 
On islands two factors may act to initiate predation of 
birds by rats. Firstly, the alien rats tend to be scavengers, 
and secondly, there may be a requirement for water other than 
that supplied by metabolism of the normal dietary in-take. ' Cott 
(1952) suggested tha-L sea bird eggs must be util.ised as a water 
source, and Habs and Heinz (1951) considered that the brown rat 
obtai.ned water requirements from eggs during birds' breeding 
seasons and from dew or rain at other times. Norman and 
Baudinette (1969) kept rattus on a diet containing only ten 
per cent water and found that they could not maintain even 
reduced body weight without suppl.ementary water being provided. 
On many islands obli.gatory water requirements may easily be 
obtained from the more vascularised plant tissues or storage 
organs. But in extreme conditions it seems that rats must 
become predators, particularly of el:-gs, to survive and that 
this source could be extensively exploj-ted. Thus Fisher and 
Baldwin (1946) observed that, "many of the Pacific Islands 
offer no large quantities of vertebrate animal food other than 
bj-rds and eggs, (and) the pressure from increases in numbers 
of rats would be exerted upon bird popula-Lions." 
Listed. below are summaries of references to predation of 
birds and their eggs, thi.s listing includes and adds to those 
given by Cott (195%). Though extensive, the references indicate 
that few systematic observations on the food preferences of rats 
have been conducted on islands where bird and rat populations 
co-exist, and more particularly on those islands where decreases 
in bird populations have been recorded. Usually statements 
regarding the diet of rats include generalisations relating to 
the content of avian material taken. Thus Steiniger (1948) 
stated that - norvegicus, which fed extensively on plant seeds 
on Norderoog (in the North Sea), had almost exterminated the 
bird population there. Bailey and Sorensen (1962) considered 
that norvegicus fed on seeds, fruit and roots, shellfish, dead 
seals, sheep, and birds but Austin (1948), who provided one of 
the few quantitative reports on regular predation, noted that 
mussels were eaten by norvegicus. For the Cape Cod area, 
Austin (19148) gave results of 19 years observations on Sterna 
hirundo Linn., S. dougalli Montagu and S. paradisea Pontoppidan. 
- 
He stated that the rat norvegicus was tEe greatest deterrent to 
successful nesting. The daily kill during the breeding season 
was between three and 20 birds, and caches of 25-150 eggs were 
found. Killing, in Austin's s-tudy colony, followed the 
breeding pattern, thus adults were taken as they becan nesting, 
eggs were later preda-Led as were chicks as they hatched. 
Howcver Austin provided no evidence of direct observation, and 
nor did Habs and Heinz (1 951 ) , who considered that norvegicus 
destroyed 60 percent of the S. hirundo eggs laid on ScharhBrn 
off Cuxhaven, Gcrmany, amounTing to some 6000 eggs within a 
month. More recently Kepler (1967), supporting his report 
photographically, has detailed losses of Diomedea immutabilis 
Rothschild on Kure where exulans caused considerable 
predation of incubating adults. Howcver Korman (1970), and 
Fall et al. (1971), found that rattus did not cause any 
prcdation even though specimens inhabiting ground nesting 
colonies of sea birds were collected, nor did the latter 
, authors observe predation of incubating adults by rattus or 
exulans . 
- 
REFERENCES TO PREDATION BY RATS 
APTERYGIFORMES 
Heaphy (in Moncrieff 1938) considered that rats were the 
most likely cause of the decline in numbers of Apteryx spp. 
in New Zealand. 
PROCELLARIIFORMES 
Alsatt (1945) believed that rats aided the decline of 
Pterodroma hypoleuca on Laysan. 
- 
Bailey and Sorensen (1962) felt -that rats were "probably 
responsible for the practical elimination of Campbell Island 
(New Zealand) as a breeding place of small petrels and 
shearwaters. " 
Bell (in Merton 1970) recorded enormous losses of young 
Pterodroma neglecta in the Kermadec group as being caused by 
R. exulans. 
- 
Campbell and Mattingley (1907) state that rats were 
causing destruction of Pelagodroma marina in Victoria, Australia 
Davidson (in Merton 1970) notes heavv CEE uredation of 
- .  , < -- & 
Pterodroma neglecta by norvegicus on Raoul Island in the 
- 
Kermadec group as being caused by R. exulans. 
Fisher (1952) mentioned that rats were predators of 
Fulrnarus glacialis. 
- 
Harris (1970) considered that rattus were almost certainly 
responsible for the poor breeding success of Pterodroma 
~haeopygia in the Galapagos. 
Holdgate and Tiace (2961) thought that rats were associated 
with declines in petrel popuiations on Tristan da Cunha and 
South Georgia. 
Johnson (1945) considered that rattus lives on the Midway 
Islands largely at the expense of seabirds and particularly 
Pterodroma hypoleuca; the young of the albatross (?~iornedea sp.) 
were also taken. 
Kepler (1967) recorded exulans feeding on incubating 
Diomedea immutabilis on Kure, and noted the absence of chicks 
- 
of Pterodroma h oleuca. 
-- 
L-6-t that rattus were responsible for the 
destruction of eggs of breeding Puffinus pacificus and P. 
griseus on Lion Island, Australia. 
- 
Larson (1967) stated that -- rattus killed nestling 
Pterodroma gia on Maui, Hawaii. 
M e r t o n P m t e d  that Pterodroma neglecta had 
decreased on Kermadec Island following the introduction of rats. 
Munro (1945) thought that ~terodroma hypoleuca and Bulweria 
bulwerii would decline unless rats were destroyed on Midway. 
Murphy (1936) lists perhaps the most extensive series of 
observations on rats predating seabirds and their eggs. At 
Tristan da Cunha, he noted that Pelagodroma -- marina was "one of 
the species which would most quickly have been wiped out by 
. . . .  rats," and he felt that rat predation was sufficient to 
account for the vast reduction of Pachyptila desolata there. 
Similarly the decrease of - P. forsteri on the same island was 
attributed to rats. On South Georgia, Murphy recorded great 
quantities of Pelecanoides georgicus bones in the rat burrows. 
The related P. urinatrix is restricted to islands without rats 
in the Tristzn group. He also noted that rats were enemies of 
Loomelania melania at the nesting grounds. 
- 
Murphy and Mowbray (1951) found no trace of Pterodroma 
cahow in localities where rats were present in Bermuda. 
Olstad (1930) recorded norvegicus living in burrows of 
Procellaria aequinoctialis and Cott suggested that they took 
"here as elsewhere .... toll of eggs and young as opportunity 
offers . " 
Stead (1936) found Pterodroma ~ycrofti eggs eaten by rats 
(exulans) and stated that alien rats had almost exterminated 
the shearwater, Puffinus tenuirostris, on Stewart Island ( ~ e w  
zealand). 
Thorensen (1967) suspected that exulans was preying on 
eggs of Pelecanoides urinatrix on Stanley Island, New Zealand. 
Tickell (1962) considered that prions, Pachyptila desolata, 
and other burrowing petrels had suffered heavily from rat 
predation on the Falkland Islands. 
PELICANIFCRMES 
Gross (1912) caught a rat (MUS alexandrinus = 5. rattus) 
sucking an egg of Phaethon americanus ( =  lepturus) in Bermuda. 
Murphy (1936)-considered that Phaethon aethereus was 
~reatlv reduced on St. Helena. aartiv bv alwne hunters and 
- , & .
"still more because of the ravages of rats and feral cats," 
and - P. lepturus on Bermuda had as its principal enemy _R. exulans. 
CICCNIIFORMES 
Layard (1850) recorded eggs of Ardea sacra as being sucked 
by rats in the Duke of York Islands (notseen, quoted from Cott 
1952). 
Berger (1970) considered that rats were destroying nests 
of Anas wyvilliana in Hawaii and thought that they were 
predators of A. lavsanensis on Laysan. 
  eve ridge a n d ~ a n i e l  (1965) thought that ducks decreased 
on Mokoia Island, New Zealand, as a result of depradations by 
norvegicus. 
- 
Coward (1914) eggs of Anas ~latyrhynchos as being 
sucked by E- (: norveg&anot seen, quoted from 
cott 19rz)T 
~ - 
~uilkr (1966) mentioned that norvegicus was a predator 
of Cygnus atratus eggs in Tasmania. 
Guile-) considered that introduced rats took eggs 
of Cereopsis novaehollandiae on breeding islands in Tasmania. 
Steininer (1948) found remains of wild ducks in rat 
- , 
burrows in Germany. 
GALLIFORMES 
Alsatt (1945) thought that rattus had affected Porzanula 
-- 
~almeri on Laysan. 
Bailey (1956) also mentioned the disappearance of Porzanug 
following the overrunning of Midway islands by rats. 
Bent (1932) recorded egg losses in Phasianus colchicus, 
Colinus virginianus and Lophortyx gambelii nests in America. 
- 
Berger (1970) considered rats were a serious predator of 
~allinula chioripbs on Hawaii and thought that rats (and other 
-- 
predators) played a role in the destruction of Pennula 
sandwichensis. 
Coward (1914) recorded eggs of Fulica atra as being 
predated by norvegicus in England. 
Cott (1952) felt that there was little doubt that eggs 
, ~, 
of Gallinula chloropus were taken by rats in Britain. 
De Groot (1927) stated that - norvegicus took eggs of 
Rallus ohsoletus in California. 
Elliott (1957) considered that rattus was the second 
most important predator of Porphyriornis nesiotis in the 
Tristan da Cunha group, man being more important. 
Fisher and Ba1dwi.n (1946) thought that the "main factor 
in the extermination of the rail (~orzanula palmeri) was the 
overrunning of both islets by rats," at Midway. 
Holdgate and Wace (1961) thought that Porphyri~nis 
populations had almost certainly decreased following the 
introduction of rats to Tristan. 
Johnston (1945) states that a decrease of Porzanula 
occurred following the introduction of rats onto Midway Atoll. 
Middleton (1935) mentioned that porvegicus would take 
eggs of Perdix erdix in Great Britain. 
N o b m O h o r d e d  rats taking eggs of Porzana pusilla 
and 2. bailloni in Andalucia. 
Austin ( 1  948) i n  e5vin~:  d e t a i l s  of l o s s e s .  consi.dered t h a t  
~. ., - 
norvegicus was the  main f a c t o r  i n  l o s s e s  of S te rna  d o u g a l l i ,  
- 
S. hirundo,  and S.  paradi.sea a t  Cape Cod, U.S.A. 
- -- 
Belcher (i<Ma.tthews 1910-27) considered t h a t  r a t s  were 
t ak ing  eggs of =cheli.da leucoparc ia  i n  A u s t r a l i a .  
l3everi.dg.e and ~ - 1 9 6 5 ) t  t h a t  r a t s  were 
~ . - ,  - 
threatening t h e  s u r v i v a l  of Coenocoryplm aucklandica on 
-- A 
isl.ands o f f  New Zealand. 
Brown (1949) thought t h a t  r a t s  were probably respons ib le  
f o r  egg l o s s e s  i n  n e s t s  of Recurv i ros t ra  avose t t a  i n  B r i t a i n .  
Campbell (1892) ment:i.oned t h a t  r a t s  took eggs and young 
of F r a t e r c u l a  a r c t i c a  i n  t h e  U . K .  
Ha r r i s  ( 1 9 6 4 ) c o r d e d  young Larus a rgen ta tus  a s  being 
taken by norvegicus i n  England. 
Johnson (19115) repor ted  t h a t  r a t t u s  was bel ieved t o  have 
taken eggs and young of white t e r n r r ~ y ( ~ i s  a l b a )  on Midway. 
Kepler (1967) recorded exulans t a k i n g  eegs of S te rna  
f u s c a t a  and yourlg of Anous sLol idus  on Kure A t o l l .  
- 
Merton (1968) found t h a t  eggs of S t e rna  fu scu ta  werc 
taken by norvegicus on Raoul I s l a n d .  
North (1946) considered t h a t  r a t s  ( ? r a t t u s )  -- took eggs of 
S te rna  f u s c a t a ,  S. anaethe- tus ,  and Anous --- s tol . idus  on Mait 
I s l a n d ,  i n  t h e  ~ z l f  of Aden. 
Rowan (1915)  sta-Led t h a t  r a t s  took eggs of S te rna  hirundo 
--
i n  B r i t a i n .  
Sprunt (1948) repor ted  t h a t  90 pcr  cen t  of eggs of yourlg 
Anous s t o l i d u s  were taken by r a t s  on Dry Tortugas Keys. 
-- 
S t e i n i g e r  (19118) repor ted  Haematopus o s t r a l e g u s ,  Numenius 
a rqua ta ,  Charadrj-us a p r i c a r i u s  and C a l i d r i s  t e s t a c e a  a s  v ic t ims  
- - 
of norvegicus on Norderoog, Germany. 
T icehurs t  (1932) repor ted  t h a t  r a t s  took eggs of Burhinus 
ocdicnen~us i n  England (no t  s een ,  quoted from Cott  19527. 
Vesey-Fitzgerald ( 1  9141 ) mentioned t h a t  r a t s  des t royed 
eggs and young of S t e rna  f u s c a t a  i n  t h e  Seychel le  I s l a n d s .  
-- -- 
COLUMBIFORrnS 
Layard (1880) recorded t h a t  r a t s  sto1.e eggs of Dacula 
pinon and - D. p i s t r i n a r i a  on the  Duke of York I s l a n d s .  
PSI'JTACIFORMXS 
Heaphy ( i n  Moncrieff 1938) considered t h a t  r a t s  had caused 
a  reduc t ion  of S t r ingops  habrophi la  i n  New Zealand. 
PASSERIFORMES 
A l s a t t  (1945)  a t t r j ~ b u t e d  the  disappearance of P s i t t i r o s t r a  
cantans  on Laysan t o  r a t s .  
-- 
Bailey (1956) a l s o  considered t h a t  r a t s  caused the  dec l ine  
of P s i t t i r o s t r a  i n  t he  Midway a r e a .  
Beveridge and Daniel (1965) mentioned depradations of 
rare birds caused by rats and considered that populations of 
Philesturnus carunculatus and Xeriicus longipes were threa-tened 
- 
by them on Great South Cape Island, New Zealand. 
Blackburn (1968) thought that exulans apparently preyed 
upon eggs and young of certain species and that this " . . .  
predat:ion seems to account for the disappearance of the Pied 
Tit (Petroica macrocephalus toitoi)," from Cuvier Island, "and 
of the Yellow-breasted Tit (~etroica m. macrocephalus) from 
Inner Chetwock Island in Cook Strait,T in-New Zealand. 
Bull (1946) found that norvegicus was the major predator 
of eggs and young of Turdus merula and T. p h i l o m a  eggs in 
- 
New Zealand. 
IIabs and Heinz (1 951 ) found several dead and half-eaten 
Sturnus vulgaris on SctiarhBrn and attributed them to rats. 
- 
~endcrson(1965) stated tha-t since the "recent rat 
inf'estati-on, the robin (~e.troica australis), bush wren (~enicus 
longipes), and fernbird Gtata) have, of course, 
- 
gone from . . . I1 Solomon Island, New Zealand. 
Johnson (1945) considered that Psittirostra cantans 
-- 
disappeared following the introduction of rats onto Midway 
Islands. 
Kenyon (1 961 ) thought that norvegicus had externlined 
Melospra melodia and Troglodytes-troglodytes - in Amchitka, 
Alaska. 
Merton (1965) stated that Phi.lesturnus carunculatus has 
been all but ex-terminated following the arrival of raktus on 
South Cape Island, New Zealand. 
Stead (1936) recorded exulans eating deserted eggs and 
youngs of Prosthemadera novaeseelandiae on Taranga Island, 
New Zealand. 
Steini.ger (1948) found rat burrows containing remains 
of S-tiurnus vulgaris, Saxicola torquata, and Regulus regulus 
in Germanv. , - 
Stoner (1937) recorded norvegicus as a predator of 
- 
R i p a r i a  ri aria in America. 
Wayne -?-z 18 9) nave some evidence of oreda%ion bv rats of 
~, - 
eggs of- -- Turdus merula and Erithacus r~becula in ~riiain. 
UISCUSSION 
Many authors have attributed the disappearance of bird 
populations, particularly those on islands, to the effects of 
introduced predators. Almost without exception rats have been 
proposed as the most important predator, and such suggestions 
have been generally accepted. Indeed, Lack (1966) considered 
that the threat of actual or even potential predation by rats 
(or other mammals) caused shearwaters and petrels to nest on 
islands without them, and suggested that extinction occurred 
where rats and cats have been introduced. More recently 
Fleming (1 969), commenting on Xeplerls (1 967) observations on 
ICure, has postulated that exulans could have been responsible 
- 
for the reducti-on of some 27 species (seven genera) of moas 
(~inornithiformes) and perhaps carinates such as Aptornis, 
Notornis and Cnemiornis. Such considerations are not supported 
by a closer examination of the references presented above. 
Attention has been paid to the more specific examples of 
rat predation on birds and their eggs in the references listed 
above, more generalised statements are legion. However, of the 
75 references swarised, 39 (52 per cent) refer to rats in 
general and only 36 relate to identified species, 17 to no=- 
gicus, 10 to rattus, and nine to exulans. More importantly, 
-- 
only two authors record direct observa%ions of active predation, 
these being Gross (1912), who caught a -- rattus sucking on egg of 
Phaethon americanus and Kepler (1967), who photographed exulans 
feeding on nesting giomedea immutabig, and none gave evidence 
of having examined food habits for any area mentioned. Pertinent 
too is the distribution of predation records in relation to 
ordinal groups. Seabi-rds (~rocellariiformes and Charadriiformes) 
predominate and account for some 35 references, but mortality in 
seabird colonies is frequently extensive, caused by a variety of 
factors including desertion, food shortages, etc., and subsequent 
carcases may have been eaten by the alien scavengers. Indeed 
most references to predation of seabirds (and other species) 
are circumstantial. 
Much of the alien rats' reputations as predators are based 
on suppositions and these have not been confirmed by food 
studies conducted on islands where birds and rats co-exist. 
Beveridge and Daniel (1965) showed that norvegicus fed mainly 
on plant material on Mokoia Island, New Zealand, and Best (1969) 
considered that birds were not important in the diet of -- 
gicus sampled in forest areas of New Zealand. Fall et al. Tm) found that on Eniwetok Atoll in the Marshall Islands, 
the diets of both -- exulans and rattus were predominantly 
vegetarian though rattus did take insect material, and the 
investigators were unable to show evidence of predation of 
birds even though samples (and observations) were made in and 
near colonies of ground nesting terns. Norman (1970) showed 
that plant material made up most of the diet and considered 
that rattus, inhabiting an island in Tasmania where extensive 
numbers of Puffinus tenuirostris bred, did not actively predate, 
although unattended eggs were apparently taken. Confrontation 
experiments between rattus and the shearwater, though perhaps 
artificial, suggested that the rats avoided any contact, either 
with unattended young, or with incubating adults. 
Thus it appears that the rats' role as an avian predator 
has been overestimated, and apart from a very few statements 
supported by direct observation, there are few data to implicate 
rats as causative agents in localised population declines. 
Other introduced mammals, such as cats, could well have played 
a more substantial part in bird population reduction and the 
role of man himself has generally been ignored. Certainly 
deserted eggs or young eaten by rats will not effect population 
size, and in most areas now colonised by the aliens a balance 
has probably been established between the rats and the local 
avifauna. For islands where the colonisation dates can be 
established, it would be profitable to determine such inter- 
actions which exist so as to examine ecological changes which 
may have taken place during a known period. Certainly the 
basic facts should be established before widespread control 
campaigns are undertaken. 
REFERENCES 
Abs, M., Curio, E., Kramer, P. and Neithammer, J. 1965. Ztir 
Emghrungsweise der h'ulen auf Galapagos. J. Grgn., Lpz. 
106: 49-57. 
Alsatt, R.S. 1945. (letter following article on tragedy in 
bird life) Elepaio 5: 49-51 . 
Austin, O.L. 1948. Predation by the common rat (~attus -- 
norvegicus) in the Cape Cod colonies of nesting terns. 
- 
Bird Banding 19: 60-65. 
Bailey, A.M. 1956. Birds of Midway and Laysan Islands. 
Denver Mus. Nat. Hist., Mus. Pic-t. no. 12. 
Bailey, A.M. and Sorensen, J.H. 1962. Subantarctic Campbell 
Island. Proc. Denver Mus. Nat. Hist. 10. 
Bent, A.C. 1932. Life histories of North American gallinaceous 
birds. Bull. U. S. natn. Mus . 162 : 1-1190. 
Berger, A.J. 1970. The present status of the birds of Hawaii. 
Pac. Sci. 24: 29-42. 
Best, L.W. 1969. Food of the roof-rat Rattus rattus -- rattus 
(L), in two forest areas of New Zealand. N.Z. Jl. Sci. 
12: 258-267. 
Beveridge, A.E. and Daniel, M.J. 1965. Observations on a 
high population of brown rats (~attus -- norvegicus 
Berkenhout 1767) on Mokoia Island, Lake Rotorua. N.J 
J1. Sci. 8: 174-189. 
Blackburn, A. 1965. Muttonbird Islands diary. Notornis 12: 
1 91 -207. 
---------- 1968. The birdlife of Codfish Island. Notornis 
15: 51-65. 
Brown, P.E. 1949. The breeding of avocets in England, 1948. 
Brit. Birds 42: 2-1 3. 
B u l l ,  P.C. 1946.  Kotes  on t h e  b r e e d i n g  c y c l e  of t h e  t h r u s h  
and b l a c k b i r d  i n  New Zea land .  Emu 46 : 198-208. 
Campbell ,  A.G.  anc! Ma-Ltingley, A.1-I.E. 1907.  A r o o k e r y  of 
s t o r m  p e t r e l s .  Emu 6 :  185-192. 
Campbell ,  J . M .  1892. On t h e  appea rance  of t h e  brown r a t  (MUS 
-- 
decumanus P a l l a s )  on A i l s a  C r a i g .  Ann. S c o t .  n a t .  H i s t .  
- 
1 :  132-134. 
C o t t  , H. B. 1952. The p a l a t a b i l i t y  of b i r d s  e g g s ;  i l l u s t r a t e d  
by t h r e e  s e a s o n s  expe r imen t s  (1947,  19h8  and 1950)  on t h e  
food p r e f e r e n c e s  of t h e  rat ( R a t t u s  n o r v e g i c u s ) ;  w i t h  
s p e c i e s  r e f e r e n c e  t o  t h e  p r o t e c t i v e  a d a p t a t i o n s  on eggs 
c o n s i d e r e d  i n  r e l a t i o n  t o  v u l n e r a b i l i t y .  P roc .  2001.  
Sac .  Lond. 122 :  1-54.  
Coward, T . A .  1914. Fauna l  s u r v e y  of Ros the rne  Mere. II. 
V e r t e b r a t a  ( n o t  s e e n ,  q u o t e d  from C o t t  1 9 5 2 ) .  Mem. P r o c .  
Mench. l i t .  p h i l .  Sac .  58: 1-37.  
De G r o o t ,  1927. The C a l i f o r n i a n  C lappe r  R a i l ,  i t s  n e s t i n g  
h a b i t s ,  enemies and h a b i t a t .  Condor 29:  259-270. 
Duffey,  B. 1964. The t e r r e s t r i a l  eco logy  o f  Ascens ion  I s l a n d .  
J .  a p p l .  Ecol .  1 : 219-247.  
E l l i o t t ,  1-I.F.I:. 1957.  A c o n t r i b u t i o n  t o  t h e  o r n i t h o l o g y  of 
t h e  T r i s t a r ~  d a  Cunha Group. I b i s  99:  51r5-586. 
F a l l ,  M . W . ,  Medina, A . R .  and Jackson ,  W.B. 1971.  F e e d i n g  
p a t t e r n s  of R a t t u s  r a t t u s  
-- 
A t o l l ,  Marshall .  I s l a n d s .  
F i s h e r ,  H.I. and Baldwj~n,  P.H. 
Midway A t o l l .  Condor 48 :  
F i s h e r ,  J .  1952. The Fulmar 
and Rat  Lus e x u l a n s  on Eniwetok 
J .  Mammal 52:  69-76. 
1946. War and t h e  b i r d s  of 
3-15. 
C o l l l n s  , Lor~dor:. 
Fl.eming, C . A .  1969. R a t s  anti moa e x t i n c t i o n .  N o t o r n i s  1 6 :  
21 0-21 1 . 
G r o s s ,  A . O .  1912.  O b s e r v a t i o n s  on t h e  y e l l o w - b i l l e d  t r o p i c  
b i r d  ( ~ h a e t h o n  arner icanus  rant) a t  t h e  Bermuda Isl&s 
Auk 29:  49-71 . 
G u i l e r ,  E.R. 1966.  The b r e e d i n g  of Black  Swan ( c y g n i s  a t r a t a  
-- 
Latham) i n  Tasmania w i t h  s p e c i a l  r e f e r e n c e  t o  some 
management problems.  Pap.  P roc .  Roy. Soc. Tasm. 100 :  31-52 
---------- 1967. The Cape Barren  Goose, i t s  env i ronmen t ,  
numbers and b r e e d i n g .  Emu 66:  21 1-235.  
EIabs, M .  and I-Ieinz, 1-1. J .  '1 95.1 . B e i t r a g  z u r  B i o l o g i e  f r e : ~ l e b e n d e r  
Wander ra t t en .  Z .  hyg.  Zool .  39:  65-87. 
ISarri.s, M.P. 1964. Aspec t s  of  t h e  b r e e d i n g  b i o l o g y  of  tkle 
g u l l s  Larus  a r g e n t a t u s ,  L. and 4. ~ a r l n u s .  Lb l s  
106:  4-6. 
---------- 1970. The b i o l o g y  of an endangered s p c c i e s ,  t h e  
Dark-rumped P e t r e l  (P te rodroma -- phaeopygia)  i n  t b e  
Galapagos 1sl.arsds. Condor 72:  76-811. 
I lenderson,  L. I?. 1965.  The t r a g e d y  o f  the  mut t o n b i r d  i s l . ands  
F o r e s t  and B i rd  158:  6-8. 
H o l d g a t e ,  M . W .  1960.  The f a u n a  o f  tkie T r i s t a n  d a  Cunha I s l a n d s .  
P h i l .  T rans .  Roy. Soc .  2Ll-9: 361-402. 
H o l d g a t e ,  M . W .  and Wace, N . M .  1961.  The i n f l u e n c e  of m a n  on 
t h e  f l o r a s  and f a u n a s  o f  s o u t h e r n  i s l a n d s .  P o l a r  Rec. '10: 
1.1.75-Lr93. 
Johnson,  M.S. 1945. Rodent c o n t r o l  on Midway I s l a n d s .  Nav. 
med. B u l l .  45: 384-398. 
Kenyon, 1 C . W .  1961 . B i r d s  of Amchitka,  Alaska .  Auk 78: 305-326. 
K e p l e r ,  C . B .  1967. P o l y n e s i a n  r a t  p r e d a t i o n  on n e s t i n g  Laysan 
A l b a t r o s s e s  and o t h e r  P a c i f i c  s e a b i r d s .  Auk 84: b26-1130. 
Lack, D. 1966. P o p u l a t i o n  s t u d i e s  of  b i r d s .  O.U.P.,  London. 
Lane, S.G. 1962.  A p r o g r e s s  s u r v e y  of b r e e d i n g  s h e a r w a t e r s  
on L ion  I s l a n d  Fauna l  Rese rve .  Emu 62:  202-204. 
L a r s o n ,  J . W .  1967. The Dark-rumped p e t r e l  i n  H a l e a k a l a  C r a % e r ,  
Maui, Hawaii .  N a t .  P a r k  S e r v i c e ,  Dept .  Lnt .  P u b l .  
Law, P.G. and B u r s - t a l l ,  T. 1956.  Macquarie I s l a n d .  I n t e r i m  
Rep. Aus t .  n a t n .  A n t a r c t .  Hes.  Exped. 1 4 .  
Laya rd ,  E.L.C. 1880. Notes  on a c o l l e c t r i n g  t r i p  i n  t h e  New 
H e b r i d e s ,  t h e  Solomon I s l a n d s ,  New B r i t a i n  and t h e  Duke 
of  York I s l a n d s .  I b i s  Lt: 290-309. 
M a r s h a l l ,  J .T .  1955. Ra%s of  t h e  Arno A t o l l ,  M a r s h a l l  I s l a n d s .  
J .  Mammal. 36: 259-263. 
Mathexis, G.M. 1910-1 927.  The B i r d s  o f  A u s t r a l i a .  Witherby 
and Co . , London. 
Merton,  D . V .  1965. A b r i e f  h i s t o r y  of  t h e  Nor th  I s l a n d  
Saddleback .  N o t o r n i s  1 2 :  208-212. 
Merton, D.V. 1968. Narrative of the Kermadec Islands 
Expedition, 10/10/66 - 29/1/67. Notornis 15: 3-22. 
---------- 1970. Kernzadec Islands expedition reports, a 
general account of bi.rdlif e. Notornis 17: 147-1 99. 
Middleton, A.D. 1935. Factors controlling the population of 
the partridge (~erdix perdix) in Great Britain. Proc. 
2001. Soc. ~ond'.(19?5):m-815. 
Moncrieff, P. 1938. Birds of Nelson Province, New Zealand. 
Emu 37: 207-234. 
Morrison, J.P.E. 1954. Animal ecology of Raroia Atoll, Tuamotus 
Atoll Res. Bull. 34(1): 1-18. 
Munro, G.C. 1945. Tragedy in bird life. Elepaio 5: 48-49. 
Murphy, R.C. 1936. Oceanic birds of South America. Macmillan, 
New York. 
Murphy, R.C. and Mowbray, L.S. 1951. New light on the cahow, 
Pterodroma cahow. Auk 68: 266-280. 
Noble, H. 1902. Forty-four days' nesting in Andalucia. Ibis 
2: 67-89. 
Norman, F.I. 1970. Food preferences of an insular population 
of Rattus rattus. J. Zool., Lond. 162: 493-503. 
Norman, F.I. and Baudinette, R.V. 1969. Water economy and salt 
balance of an insular population of Rattus rattus Linnaeus. 
J. Mammal. 50: 487-493. 
North, M.E.W. 1946. Mai-t Island--a bird rock in the Gulf of 
Aden. Ibis 88: 478-501. 
Olstad, 0. 1930. Rats and reindeer in the Antarctic. Scient. 
Results. Norw. Antarct. Exped. 4: 3-20. 
Rowan, W .  1915. The Blakeney Point ternery. Brit. Birds 8: 
250-266. 
Schiller, E.L. 1956. Ecology and health of Rattus at Nome, 
Alaska. J. Mammal. 37: 181 -1 88. 
Sprunt, A. 1948. The tern colonies of the Dry Tortugas Keys. 
Auk 65: 1-19. 
Stead, E.F. 1936. The n~aori rat. Proc. R. Soc. N.Z. 66: 178- 
181. 
Steiniger, F. 1948. Biologische Beobachtungen an freilebenden 
Wanderratten auf Hallig Norderoog. 2001. Anz., Suppl. 
13: 152-156. 
Stoner, D. 1937. The house rat as an enemy of the Bank Swallow. 
J. Mammal. 18: 87-89. 
Thorensen, A.C. 1967. Ecological observations on Stanley and 
Green Islands, Mercury Group. Notornis 14: 182-200. 
Ticehurst, C.B. 1932. A history of the birds of Suffolk. 
(not seen, quoted from Cott 1952). Gerney and Jackson, 
London. 
Tickell, W.L.N. 1962. The Dove Prion, - Pachyptila -- desolata 
Gmelin. F.I.D.S. Sci. Rep. 33. 
Troughton, E. LeG. 1965. Furred animals of Australj~a. (8th 
edition). Angus and Robertson, Sydney. 
Vesey-Fitzgerald, D. 1941. Further contributions to th 
ornithology of -the Seychelles Islands. Ibis 5: 51 
Walker, E.P. 1964. Mammals of the World. John Hopkins 
Baltimore. 
Wayne, R. 1849. Blackbirdts eggs sucked by a rat. Zoo 
7: 2495. 
-531. 
ogis t