Caroline Atoll

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 i b l e y

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. c h a r t 928.

NOTES ON THE VASCULAR FLORA AND TERRESTRIAL VERTEBRATES OF CAROLINE ATOLL SOUTHERN LINE ISLANDS

'

by Roger B. c l a p p 2 and Fred C. s i b l e y 3

From 0900 on 17 June t o 0615 on 19 June 1965 Caroline A t o l l was v i s i t e d by a f i e l d p a r t y from t h e P a c i f i c Ocean B i o l o g i c a 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 p a r t y , l e d by S i b l e y , c o l l e c t e d and made o b s e r v a t i o n s on v a s c u l a r 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 t h e n o r t h e r n t w o - t h i r d s o f Nake were v i s i t e d . P r i o r knowledge o f t h e b i o t a of Caroline A t o l l i s v e r y s c a n t , d e r i v i n g 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. H a r t f o r d i n 1883.

This paper summarizes e a r l i e r d a t a and p r e s e n t s r e c e n t POBSP o b s e r v a t i o n s on t h e 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 d e n t i f y i n g many of them f o r t h e f i r s t time.

DESCRIPTION

Caroline i s a low, d e n s e l y v e g e t a t e d , 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 l o n g i t u d e . I t i s about 125 n a u t i c a l m i l e s e a s t of Vostok I s l a n d and 125 m i l e s n o r t h e a s t of F l i n t I s l a n d . The a t o l l i s 5.75 miles long on t h e north-south a x i s , and a t t a i n s a maximum b r e a d t h of 1.125 m i l e s a t t h e south end. I t s a r e a i s ca. 942 a c r e s and i t s circumference around t h e o u t e r r e e f i s about 1 3

m i l e s

(Holden and Qualtrough, 1884;

Maude, 1953)

.

The c e n t r a l lagoon h a s much l i v i n g c o r a l , and c o r a l heads break t h e s u r f a c e . There a r e t h r e e l a r g e i s l a n d s , Nake and Long t o t h e n o r t h

(conjoined on t h e e a s t ) , and South t o t h e s o u t h . Around t h e a t o l l r i m and w i t h i n 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 s e p a r a t e d by water.

Dry, unvegetated, f l a t a r e a s o f c o r a l rock d i v i d e t h e i s l e t s , i n d i c a t i n g t h a t a t one time over 25 s e p a r a t e i s l e t s may have e x i s t e d .

~ ~~ ~~ ~ ~~~ ~ ~-

1. Paper No. 61, P a c i f i c Ocean B i o l o g i c a l 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 B i o l o g i c a l Survey Program, Smithsonian I n s t i t u t i o n . 3. P o i n t Reyes Bird Observatory, Bolinas, C a l i f o r n i a .

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 e d by p a r t i e s from a number of passing ships' I t was v i s i t e d on 16 December 1795 by t h e B r i t i s h sloop Providence, commanded by W. R .

Broughton, who named t h e i s l a n d Caroline a f t e r t h e daughter of S i r P.

Stephens, F i r s t Lord of the B r i t i s h Admiralty. In 1821 it was sighted by Captain Thornton of t h e English whaler Supply f o r whom it received t h e a l t e r n a t e name Thornton (Bryan, 1942). I t was v i s i t e d 10 t o 13 October 1825 by Hiram Paulding on t h e 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 e d t h e a t o l l from t h e whaler Tuscan. In 1875 Caroline was v i s i t e d by C . D. Voy, a n a t u r a l i s t from C a l i f o r n i a 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 p a r t y from t h e U.S.S. Hartford was t h e r e t o observe a t o t a l e c l i p s e of t h e sun (Holden, 1884). During t h e v i s i t observations and c o l l e c t i o n s were made of p l a n t s (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 i n v e r t e b r a t e s 'were made by Dixon (1884).

Archaeological remains found on Caroline i n d i c a t e t h a t t h e a t o l l was occupied, possibly by people from t h e Tuamotus (Emory, 1947), p r i o r t o European exploration of t h e P a c i f i c , but t h e f i r s t recorded occupancy began i n 1846 when C o l l i e and Lucett, a B r i t i s h firm, established a

small n a t i v e a g r i c u l t u r a l experiment t h e r e (N.I.D., 1943).

Between 1865 and 1872 Messrs. Brown and Brothers planted coconuts on t h e a t o l l and i n J u l y 1868 t h e r e were 27 human occupants. In 1872 t h e i s l a n d 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 q u a n t i t i e s (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 p l a n t a t i o n from 1916 u n t i l 1934 when t h e company f a i l e d . Exports during t h e l a t t e r p a r t of t h i s period amounted t o about 14 tons per

annum. For a short time t h e r e a f t e r Caroline was worked,as a coconut p l a n t a t i o n by t h e administrator f o r t h e company's a f f a i r s . By 1936 only

a few Tahitian families were s t i l l occupying t h e 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 t h e occupation leases were cancelled and possession of t h e a t o l l reverted t o t h e B r i t i s h Western High P a c i f i c Commission (Maude, 1953).

VEGETATION

In 1825, Paulding (1831) noted t h a t Caroline had "some t r e e s of a l a r g e size upon i t and i n most p l a c e s a t h i c k growth of underwood" and f u r t h e r remarked t h a t "a boat load of pepper-grass and pursley, of which t h e r e was a great abundance" was obtained. He only mentions seeing one coconut t r e e which, i n l i g h t of Bennett's observations (see below), suggests t h a t South Island was n o t v i s i t e d .

Nearly t e n years l a t e r Bennett (1840) made more d e t a i l e d observations of t h e vegetation. He recorded t e n flowering p l a n t s and a f e r n , i n t r o - duced three other species, and r e l a t e d t h a t

-

Cocos were found only i n a grove on t h e northeast s i d e of South Island--a grove t h a t covered about o n e - f i f t h of t h e land a r e a of t h a t i s l a n d . Bennett s t a t e d t h a t t h e a t o l l was "covered with verdure" and t h a t "the i n t e r i o r of t h e i s l a n d [was]

a surface of sand, mingled with c o r a l debris as well a s with decayed vegetable and animal matters, which give it increasing f e r t i l i t y " . He a l s o mentioned t r e e s " a t t a i n i n g t h e height of twenty f e e t " which may i n d i c a t e t h a t Cordia o r Pisonia groves o r both covered a more extensive a r e a i n t h e l a s t century. Bennett s t a t e d t h a t "the woodlands a r e

c h i e f l y composed of two species of Tournefortia" which we can only i n t e r p r e t as a reference t o Cordia as well as Tournefortia. We have not been able t o determine t h e present d i s p o s i t i o n of Bennett's p l a n t c o l l e c t i o n , i f indeed i t s t i l l e x i s t s .

The only reasonably thorough c o l l e c t i o n of p l a n t s was made by W.S.

Dixon during t h e v i s i t of t h e U.S.S. Hartford. Many o f t h e p l a n t species collected or observed by Dixon were probably introduced during t h e e a r l i e r occupation of t h e i s l a n d . Dixon's c o l l e c t i o n s and obser- v a t i o n s (27 or 28 flowering p l a n t s , a f e r n , an alga, and a fungus) were subsequently reported by Trelease (1884). A l l p l a n t s , with t h e exception o f Fleurya r u d e r a l i s , were c o l l e c t e d on South Island.

Below i s a short summary of t h e vegetation of each l a r g e i s l a n d and of t h e i s l e t groups as observed by t h e POBSP i n 1965.

South Island. Old Cocos groves cover most o f South Island.

-

Interspersed with these groves a r e t h i c k e t s o f Morinda t h a t a r e often associated with

Ipomoea tuba. In some open areas i v h e r e o c o s have died o r f a l l e n t h e

-

grass Lepturus repens forms a n e a r l y closed stand with Ipomoea. A Suriana-Le turus zone forms a f r i n g i n g association around t h e i s l a n d . Suriana

fE-

orms a dense continuous border of shrubs on t h e north s i d e bordering t h e lagoon (Figure 2 ) . On t h e other s i d e s t h e Suriana shrubs a r e t a l l e r ( t o 2 m), l e s s compact, and more s c a t t e r e d . Patches of Lepturus a r e s c a t t e r e d here and t h e r e and often extend well outside and beyond t h e Suriana zone towards t h e high-tide l i n e . Individual t r e e s

of Pisonia grandis and Cordia subcordata were likewise s c a t t e r e d over the i s l a n d .

Nake Island. On Nake, which had been planted t o

-

Cocos l i k e South Island, groves extend t h e e n t i r e length o f t h e i s l a n d . The g r e a t e r robustness of these - Cocos groves, t h e occurrence of Psilotum, and t h e more frequent occurrence of - Tacca, suggest t h a t Nake received more p r e c i p i t a t i o n than other portions of t h e a t o l l .

Associations of Pandanus, Morinda and Tournefortia occur i n open areas of t h e i n t e r i o r and along t h e edge of t h e

-

Cocos stands. Along t h e northeast s i d e an almost continuous stand of Tournefortia borders the area between t h e

-

Cocos groves and t h e open sandy beach with i t s s c a t t e r e d clumps of Lepturus and t h e ubiquitous Boerhavia repens. Some older Tournefortia t r e e s were n e a r l y 3 meters high. Tacca was found i n s c a t t e r e d groups i n damp muck areas under t h e C o c o s v e s . The only Tribulus observed on t h e e n t i r e a t o l l was f o a n an open sandy area among Tournefortia shrubs on t h e south end of t h e i s l a n d .

Long Island. Clumps of Morinda and Cordia occur on t h e north end.

Pisonia, Cordia and Suriana were a l s o observed. On both s i d e s of t h e island Tournefortia forms a f r i n g e with open areas supporting a s s o c i a t i o n s of Lepturus, Boerhavia, and Portulaca (Figure 3 ) .

Windward I s l e t s . Small Cordia groves a r e present on most of these small eastern i s l e t s . Brothers I s l e t has a few

-

Cocos t r e e s . Suriana, forming a dense stand with Tournefortia, was found ( t o 3 m i n height) on t h e i s l e t j u s t south of Arundel I s l e t . Tournefortia i s a l s o an important component on t h e 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 i s much s p a r s e r than on those on t h e windward s i d e of t h e a t o l l . Pandanus occurs on t h e t h r e e small i s l e t s south on Nake I s l a n d . Further south l i e s an i s l e t with a few Cocos t r e e s and Pisonia. The other i s l e t s on t h e 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 s a n d - f i l l e niches i n t h e expose

77-

c o r a l rubble while t h e Heliotropium is found i n sand on t h e lagoon s i d e of t h e i s l e t s .

The general aspect of t h e vegetation indicated a lengthy dry s p e l l p r i o r t o our v i s i t .

VASCULAR FLORA OF CAROLINE ATOLL

Vascular p l a n t s were c o l l e c t e d by C. R. Long (POBSP) on 17 and 18 June. Herbarium specimens w i l l be deposited i n t h e herbarium of t h e University of Hawaii and some duplicates i n t h e herbaria of t h e United S t a t e s National Museum and t h e Bernice P. Bishop Museum.

In t h e following l i s t c o l l e c t i o n numbers a r e those of Long's.

Species not previously known t o occur on t h e a t o l l a r e marked with an a s t e r i s k .

Psilotaceae

*Psiloturn nudum (L.) Beauv.

Found only on Nake I . , common on wet base o f Cocos, Long 3233.

Polypodiaceae Polypodium scolopendria Burm. f .

Collected by Dixon and recorded by Bennett (as Polypodium phymatodes L ) . Ground cover under Cocos f o r e s t s on Nake I . , Long 3244; under s c a t t e r e d Cocos north e n d m o n g I . , 3250; South 1 x 2 2 8 7 .

-

A p p a r e n t l y t h r i v i n g even under very dr-nditions.

Pandanaceae Pandanus t e c t o r i u s 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 i n d i c a (L.) Gaertn.

Collected by Dixon. Not found by t h e POBSP.

Eragrostis t e n e l l a (Link) Beauv.

Collected by Dixon and reported by Trelease as E. plumosa Lk.

-

Not found by t h e POBSP.

Lepturus repens (Forst. f . ) R. B r .

Collected by Dixon. Tufts t o 1.5 dm high i n c o r a l sand, on second i s l e t south- of Long I . , Long 3211; i s l e i n o r t h e a s t of ~ b u t h I . , 3221; common growing i n c o r a l sand s e v e r a l meters above lagoon,

-

Nake I . ,

-

3236; exposed s i t e i n sand on e a s t windward s i d e of Nake I . ,

3238;

exposed s i t e i n sand, Long I . ,

-

3247; near lagoon shore of west s i d e of fourth i s l e t north of Bird I . , 3259; numerous

-

clumps under Suriana on South I., 3286.

-

D i g i t a r i a sp.

Collected by Dixon and recorded by Trelease as Panicum ( D i g i t a r i a ) marginata Lk.? C. R. Long who examined Dixon's specimen believes

t h a t i t i s a D i g i t a r i a which may be i d e n t i c a l t o

-

^3235.

Bromeliaceae Ananas comosa L .

Collected by Dixon who found it c u l t i v a t e d on Caroline. Not found by t h e POB&.

Palmae Cocos n u c i f e r a L .

Reported as "cocoa-nut t r e e s " by Bennett and i d e n t i f i e d as above by Dixon. Dry groves of South I . , Long 3285. Extensive stands cover Nake and South I s . ; a s c a t t e r e d number on north portion of Long I .

Liliaceae Crinum sp.

An u n i d e n t i f i e d l i l y c o l l e c t e d 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 f o r e s t of Nake I . ,

-

^3234. Numerous patches found i n m u c k m h e south en= Nake I .

Moraceae Ficus c a r i c a L.

Collected by Not found by

Fleurya r u d e r a l i s

.

Reported by Bennett and c o l l e c t e d by Dixon. Common i n shady areas of South I . , Long 3215; s c a t t e r e d on an exposed s i t e i n c o r a l rubble and sand, second i s l e t south of Nake I . (west s i d e ) , 3229; under shade of Cocos and Pisonia on north s i d e of Long I . ,

-

-

3253. Many seedlings observed on Long I .

-

Dixon. An introduction c u l t i v a t e d f o r i t s f r u i t . t h e POBSP.

Urticaceae (Forst. f.'l Gaud. ex Wedd.

Chenopodiaceae

Boussingaultia g r a c 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. T r e l e a s e t s comment t h a t t h e specimen c c l l e c t e d by Dixon was a "vine climbing over portico" suggests t h a t it was introduced by r e s i d e n t s of Caroline. Not found by t h e POBSP.

Nyctaginaceae Boerhavia repens L .

Reported by Bennett as B. h i r s u t a and c o l l e c t e d (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, l a r g e 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 o f 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 t h e north end of Long I .

2-

Portulacaceae Portulaca l u t e a Sol.

Reported by Bennett. Trelease s t a t e d t h a t Dixon recomized two

-

v a r i e t i e s bf Portulaca but n e i t h e r was c o l l e c t e d . Stems clumped, flowers yellow, i s l e t northeast of South I . ,

--

Long 3223; clumps 1.5 dm high, common i n open c o r a l 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; f o u r t h 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 s c i d i u n Forst. Also reported by Bennett as a "Lepidium of 1uxuFiant tI- growt

.

Not found by t h e POBSP.

Leguminosae Inocarpus f a g i f e r u s (Park.) Fosberg

Introduced by Bennett but not found subsequently.

Zygophyl laceae

*Tribulus c i s t o i d e s L.

Stems t o 0.8 m long i n an open sandy a r e a among Tournefortia shrubs on Long I . , Long 3245. Not seen elsewhere on t h e a t o l l .

Surianaceae Suriana maritima L.

Collected by Dixon. Shrub t o 1 . 8 m high on e a s t 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 t h e POBSP.

Phyllanthus amarus Schum. and Thonn.

Collected by Dixon and recorded by Trelease as

-

P. n i r u r i L . , Herb t o 4 dm, common on t h e north s i d e of South I . , Long 3283.

Malvaceae Sida f a l l a x Walp.

Collected by Dixon who only found one specimen. Not found by t h e - POBSP.

Guttiferae

Calophyllum ino hyllum L. Collected y Dlxon but not found by t h e POBSP.

+

Caricaceae Carica

papaya

L.

Collected by Dixon. An introduction not found by t h e POBSP.

Cucurbitaceae Cucurbita L .

"Recognized i n c u l t i v a t i o n " by Dixon but not found by t h e POBSP.

Convolvulaceae

*Ipomoea pes-caprae s s p . b r a s i l i e n s i s (L.) Van O o s t s t r .

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 t h e a t o l l .

Ipomoea b a t a t a s L .

Introduced by Bennett but not found subsequently.

*Ipomoea tuba (Schlecht.) G. Don

T r a i l i n e 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.

- -

"

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

>.

-

Boraginaceae Cordia subcordata Lam.

Collected by Dixon. Tree t o 4 m near lagoon, South I . , Long 3213;

--

t r e e t o 3 m high i n i n t e r i o r of i s l e t i n c o r a l rubble about 15 meters above high t i d e l i n e , west s i d e 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 i o 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 c o l l e c t e d 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 i n exposed s i t e i n c o r a l

=el on lagoon s i d e of second i s l e t south of Nake I . (west s i d e ) , 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 c o r a l gravel under Suriana on t h e southwest s i d e of South I . ,

3288.

Tournefortia argentea L . f .

Probably seen by Bennett, and c o l l e c t e d by Dixon. Small t r e e , with white fiowers, i . 5 m high, edge of lagoon; South I., Lon 3216;

edge o f i s l e t northeast of South I . ,

-

3226; shrub 3 m d , x v e h i g h - t i d e l i n e , 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. R e l e a s e noted t h a t it had been probably introducFd. Not found by t h e POBSP.

Rubiaceae Morinda c i t r i f o l i a L.

Reported by Bennett and c o l l e c t e d by Dixon. Small t r e e , 2 m high

~ & t h I., iong 3214; young p l a n t , 6- dm high, South I.,

3217;

shrub t o 2.5 m, Nake I . ,

-

3232; common a t edge of Pisonia f o r e s t north end of Long I . ,

-

3254; small t r e e t o 3 m f o r m m n s e t h i c k e t s , c e n t r a l a r e a of South I . ,

-

^3282.

TERRESTRIAL VERTEBRATES OTHER THAN BIRDS

"Small lizards1' were reported i n 1825 by Paulding (1831) but t e n years l a t e r Bennett s t a t e d t h a t he had seen no " l i z a r d s o r o t h e r land amphibia." Dixon (1884) reported t h r e e species of l i z a r d s but d i d not i d e n t i f y them. Dixon a l s o reported t u r t l e s (Chelonia mydas?)

-

but noted they were not numerous.

Three species o f l i z a r d s were found on t h e a t o l l by t h e POBSP and specimens were obtained of each: one Black Skink (Emoia

-

^{nigra, USNM}

158358), two Polynesian Geckos (Gehyra oceanica. USNM 158353-354), and t h r e e 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 e d t h e a t o l l seven years l a t e r . In 1848 several n a t i v e families with ' p i g s , fowls, turkey, etc."

were transported t o Caroline by Edward Lucett (1851) and i n 1868 t h e 27

persons l i v i n g on t h e i s l a n d were r a i s i n g stock, p i g s , and poultry (Bryan, 1942). No livestock were reported i n 1883 by Dixon, nor were any found on t h e i s l a n d s by t h e POBSP.

Rats were seen by both Bennett and Dixon. Bennett s t a t e d t h a t t h e r a t s "were of a red-brown color," while Dixon noted t h a t "the brown r a t . . . i s not numerous" and t h a t " t h e i r n e s t s were made i n t h e cocoa-nut t r e e s , j u s t a t t h e base of t h e 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 ( i n mm) o f t h e t o t a l length, t a i l , hind foot, and e a r f o r t h e 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 t h e b i r d s seen by Bennett and Dixon were i d e n t i f i e d t o species but some were described i n enough d e t a i l t o allow an

i d e n t i f i c a t i o n .

Bennett (1840) reported seven species: "a t r e e - n e s t i n g booby"

(=Sula

--

s u l a ) , " f r i g a t e b i r d s " (Fregata sp .?)

,

"a coot"

( 1 ,

wcurlews"

(=Numenius t a h i t i e n s i s ) , "a specles of Totanus, s i m i l a r t o t h a t we Y

found a t Raitea, with t h e exception t h a t i t s legs a r e lemon-color, while i n t h e Raitean species they were blue" (perhaps Heteroscelus

incanum, while t h e b i r d seen a t Raitea may have been P l u v i a l i s

dominica), "a great number of small pigeons, with white head and neck, and t h e r e s t of t h e i r plumage a r i c h brown color" (probably Anous

-

t e n u i r o s t r i s but possibly - A. stolidus), and "small white t e r n s " (=Gygis

alba).

Dixon (1884) reported 1 2 species but s p e c i f i c i d e n t i f i c a t i o n i s reasonably c e r t a i n f o r only four: "ploverg1 (P. dominica), @tcurlewlf (N. t a h i t i e n s i s ) , a heron t h a t occurred i n "two v a r i e t i e s , brown and wKitet' (=Demigretta s a c r a ) , and "an all-white t e r n f 1 (=G.

- -

^alba)

.

^He

a l s o 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. ?), t h e "Frigate b i r d q f (Fregata sp.) a "Gannet" and a " ~ o o b ~ ~ o b a b l ~

--

Sula s u l a and

-

Sula sp.?); he reported t h a t a colleague had heard "the notes of a singing bird" ( ? ) , Arundel (1890) s t a t e d t h a t "a pigeonff occurred on Caroline. This may have r e f e r r e d t o Ducula but equally l i k e l y t o

-

^Anous.

Thus, although a f a i r l y wide v a r i e t y of b i r d s had been reported p r i o r t o the POBSP v i s i t , s p e c i f i c i d e n t i f i c a t i o n s were reasonably

c e r t a i n f o r only f i v e species: Red-footed Booby, Golden Plover, B r i s t l e - thighed Curlew, Reef Heron, and White Tern.

In t h e following species accounts t h e numbers i n parentheses follow- ing t h e species name a r e an estimate of t h e t o t a l number of f l y i n g b i r d s , including breeding a d u l t s , nonbreeding adults, subadults and juveniles.

Following t h i s f i g u r e i s another which gives the>estimated number of breeding b i r d s .

These estimates a r e not very accurate s i n c e t h e b r e v i t y of t h e v i s i t and t h e l a r g e number of i s l e t s v i s i t e d precluded d e t a i l e d census work. We present them because we f e e l t h a t such estimates, although p a r t l y subjective, show r e l a t i v e abundance of t h e 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 b i r d s )

-

Sula d a c t y l a t r a POBSP personnel found two n e s t s , one containing two eggs, t h e o t h e r a n e s t l i n g , on t h e e a s t s i d e of Nake Island along t h e ocean beach.

Navy personnel reported two o t h e r n e s t s with eggs from t h e same area.

BROWN BOOBY (ca

-

15 ^f 10%

--

a t l e a s t 8 breeding b i r d s )

-

Sula leucogaster Three n e s t s , two with eggs and one with a n e s t l i n g , were found on Nake Island. Five t o e i g h t a d u l t s were seen r o o s t i n g on emergent portions of t h e c o r a l r e e f along t h e southeast passage between South

Island and t h e 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 b i r d s )

--

Sula s u l a Red-footed Boobies were found n e s t i n g on almost a l l i s l a n d s except

South. Nests were found on a wide v a r i e t y of p l a n t s (Cordia, Morinda, Pisonia, and Tournefortia) and contained eggs and young, with t h e l a t t e r ranging i n s i z e from r e c e n t l y hatched young t o near-fledging juveniles. Several other n e s t s were found t h a t had been r e c e n t l y l i n e d with f r e s h Pisonia leaves, suggesting t h a t some females had not y e t l a i d . In l a t e April, 1835 (Bennett, 1840) Red-footed Boobies were building n e s t s 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 n e s t l i n g , and 495106 and 495107 were c o l l e c t e d from eggs).

GREAT FRIGATEBIRD (10,000 ^f 25%--8,000 ^f 25% breeding Fregata minor b i r d s )

Great Frigatebirds were found n e s t i n g on almost a l l i s l a n d s . Both eggs and young were present. Nests a r e found i n t h e same h a b i t a t

u t i l i z e d by Red-footed Boobies.

Specimens: 2 99, both c o l l e c t e d from eggs, 18 June 1965: USNM 495092 ovary 18 x 10 mm, l g . ovum 4 x 4 mm, w t . 921 g; USNM 495093, l g . ovum 3 mm, w t . 1200 g.

LESSER FRIGATEBIRD (1,000

* lo%,

400 10% breeding b i r d s ) Fregata a r i e l

-

Lesser Frigatebirds nested only near t h e north end of Long Island (Figure 1) where a small colony o f ca 400 b i r d s had constructed n e s t s i n low Morinda bushes and i n small ~ o r x a t r e e s , both o f which were much overgrownby Ipomoea

-

^tuba. Only eggs were found i n t h e n e s t s , but f l y i n g immatures, presumably b i r d s from a previous breeding season, were noted. Other f r i g a t e b i r d s were seen displaying and building n e s t s .

I

GOLDEN PLOVER (30 f 10%) P l u v i a l i s dominica

!

Golden Plovers, l i k e o t h e r shorebirds, were scarce but generally d i s t r i b u t e d throughout t h e c o r a l r e e f s . They appeared, l i k e other shorebirds, t o be somewhat more abundant along t h e o u t e r perimeter of

I t h e 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 t a h i t i e n s 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 e s t e s 3 x 2 mm, w t . 121 g.

I

!

RUDDY TURNSTONE (ca

-

⁵⁾

REEF HERON (40 ^f 25%)

Arenaria i n t e r p r e s Demigretta s a c r a I Most Reef Herons were seen foraging singly around t h e r e e f s but

appeared more common along t h e i n t e r i o r lagoon. No n e s t s were found

~

but t h e s i z e of t h e gonads of one specimen (USNM 495303) suggests t h a t t h e species may breed t h e r e .

Of t e n d i f f e r e n t individuals tabulated on 18 June, h a l f were white morph, h a 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 , l g . ovum 10 mm, w t . 541 g; USNM 498280, d(ske1eton).

SOOTY TERN (ca

-

^{500,000 f 25%--ca}

-

^400,000

*

breeding b i r d s ) Sterna f u s c a t a Sooty Tern colonies were found on a number of t h e i s l e t s and

s e v e r a l geographically d i s c r e t e colonies were found on t h e same i s l e t . In one instance colonies showed a d i s c r e t e but small d i f f e r e n c e i n t h e i r breeding cycles on t h e same i s l a n d (Table 1 ) . Most colonies contained incubated eggs t o week-old chicks, i n d i c a t i n g 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 S t a t u s Three groups of i s l e t s on

west s i d e of a t o l l j u s t south o f Nake I .

South h a l f 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 g h t l y incubated Eggs t o week-old chicks (ca 20,000 eggs andT0,OOO n e s t l i n g s )

Eggs t o week-old chicks

*Most estimates determined by i n t e n s i v e banding o r by estimating n e s t i n g density and colony area.

On most i s l a n d s and on t h e i s l e t south o f Arundel, n e s t s were

located i n t h e 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 n e s t l i n g s by t h e coconut crab (Birgus l a t r o ) was noted i n t h e colonies on t h e i s l e t south of Arundel.

-

Specimens: 1 ^d, 4 99, 17 June 1965: USNM 495481, d, r t . 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 b i r d s )

-

Anous s t o l i d u s 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 b i r d s ) Anous t e n u i r o s t r i s were found n e s t i n g on most i s l a n d s . The few n e s t s eggs o r young.

WHITE TERN (4,000 t 25% - - s e v e r a l thousand breeding b i r d s ) Gygis

-

a l b a White Terns were found breeding on most i s l a n d s . About h a l f of t h e

breeding b i r d s were with eggs, and h a l f with young.

Specimen: 18 June 1965: USNM 495608, 0 , l a r g e s t ovum 1.5 mm, w t . 100 g.

BLUE-GRAY NODDY (ca - 5) Procelsterna cerulea

Several Blue-gray Noddies were seen f l y i n g over t h e c e n t r a l lagoon and one of these was c o l l e c t e d . No b i r d s were seen on t h e ground and no n e s t s were found.

Specimen: 18 June 1965: USNM 495540, 0 , ^ovary 7 x 9 mm, l g . ovum 2 mm, w t . 54.1 g ( i n heavy body molt).

SUMMARY

Observations and c o l l e c t i o n s of t h e f l o r a and v e r t e b r a t e fauna made by t h e P a c i f i c Ocean Biological Survey Program i n June 1965 a r e reported herein.

Twenty species of p l a n t s were c o l l e c t e d includine 18 flowerine p l a n t s , a f e r n , and a G i l o t u m . Of these t h e p s i l o t i (Psilotum nldum) and t h r e e flowering p l a n t s (Tribulus c i s t o i d e s , Ipomoea pes-caprae ssp.

b r a s i l i e n s i s , Ipomoea tuba) had not been previously reported from t h e

-

a t o l l . Five other species were c o l l e c t e d f o r t h e f i r s t time (Pandanus t e c t o r i u s , Cocos n u c i f e r a , Tacca leontopetaloides, Boerhavia repens, Portulaca l u t e a ) . Many o t h e r species previously recorded from Caroline were not f- Most o f these were introduced species (e.g., Carica papaya, Curcurbita

E ,

Ficus c a r i c a ) which probably did n o t survive t h e r i g o r s of existence on t h e a t o l l .

Three species of l i z a r d s were collected and i d e n t i f i e d (Emoia

-

nigra, Gehyra oceanica, and Lepidodactylus lugubris), none o f which had been previously reported from t h e a t o l l but a l l of which a r e widespread i n Polynesia. ~ b l ~ n e s i a n Rats (Rattus exulans), which had not been pre- viously i d e n t i f i e d t o species, were a l s o collected.

Fifteen species o f b i r d s were recorded. Four were migrant shorebirds (Golden Plover, Bristle-thighed Curlew, Wandering T a t t l e r , Ruddy

Turnstone) t h a t occur commonly i n t h e c e n t r a l P a c i f i c . Reef Herons possibly breed on Caroline but may have wandered t o t h e i s l a n d from o t h e r breeding s t a t i o n s i n t h e a r e a . The remaining ten species a r e a l l seabirds t h a t breed i n t h e c e n t r a l P a c i f i c . Of these, a l l were found breeding except t h e Blue-gray Noddy which i s apparently only a v i s i t o r

t o t h e 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 a r e p a r t i c u l a r l y indebted t o C . R. Long who d i d a preliminary d r a f t of t h e vegetation s e c t i o n of t h i s account. We a l s o thank t h e other members of t h e f i e l d p a r t y who contributed d a t a f o r 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 t h e Herbarium of t h e University of Wisconsin, aided Long i n examining Dixon's b o t a n i c a l c o l l e c t i o n . The

l a t e Doris M. Cochran i d e n t i f i e d t h e r e p t i l e s and Ralph D. Kirkpatrick made h e l p f u l comments on t h e mammals. We a l s o thank Patrick J . Gould, C . Douglas Hackman, George E. Watson, and Paul W. Woodward who read t h e manuscript and made h e l p f u l suggestions. Logistic support was furnished by t h e United S t a t e s Navy.

LITERATURE CITED

Arundel, J . T. 1890. The Phoenix Group and o t h e r i s l a n d s of t h e P a c i f i c . [Read before t h e Geographical Society of t h e P a c i f i c

...

San Francisco 3 March 1885 and r e p r i n t e d i n t h e New Zealand Herald, Auckland, 5 and 12 J u l y 18901.

Bennett, F. D. 1840. Narrative of a whaling voyage around t h e 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 t h e Hawaiian Chain.

Tongg Publ. Co., Honolulu, 253 p.

Butler, A. G . and H. S t r e c k e r . 1884. Memorandum of t h e b u t t e r f l i e s , e t c . o f Caroline Island, i n Report o f t h e operations of the American Expedition t o observe'the t o t a l e c l i p s e 1883, May 6 a t Caroline Island, South P a c i f i c Ocean. Nat. Acad. S c i . , Mem. No. 2 : 92-96.

Dixon, W. S. 1884. Notes on the zoology of Caroline Island, Report of the operations of t h e American Expedition t o . . . Caroline I s l a n d . . . Nat. Acad. S c i . , Mem. No. 2: 90-92.

Emory, K. P. 1947. Tuamotuan r e l i g i o u s s t r u c t u r e s and ceremonies Bernice P. Bishop Mus. Bull. 191: 102 p .

Fowler, H. W. 1899. Observations on f i s h e s from t h e Caroline I s l a n d s . Proc. Acad. Nat. S c i . , Phila. vol. 51: 482-496.

---

1901. Fishes from Caroline Island. Proc. Acad. Nat. S c i . , Phila. vol. 53: 324-326.

Holden, E . S. 1884. Journey from New York t o Caroline Island and r e t u r n , i n Report of the...American Expedition t o . ..Caroline I s l a n d . . . Nat.

- Acad. Sci., Mem. No. 2: 16-20.

Holden, E . S. and E. F . Qualtrough. 1884. Description of t h e i s l a n d , - i n Report of the...American Expedition to...Caroline I s l a n d . . . Nat.

Acad. Sci., Mem. No. 2: 22-26.

Lucett, E . 1851. Rovings i n t h e P a c i f i c 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 B r i t i s h Central P a c i f i c Islands: a r e p o r t on land c l a s s i f i c a t i o n and u t i l i z a t i o n . Proc. 7th P a c i f i c Science Congress 6: 89-97.

---

1959. Spanish d i s c o v e r i e s i n t h e c e n t r a l P a c i f i c . Jour.

Polyn. SOC., 68: 284-326.

N.I.D. [Great Britain, Naval I n t e l l i g e n c e Division.] 1943. P a c i f i c Islands, v o l . 11. Eastern P a c i f i c , H.M. Stationery Office, London, xvi + 739 p.

Paulding, H. 1831. Journal of a c r u i s e of t h e United S t a t e s Schooner Dolphin

...

^{G . & C. &} H. C a r v i l l , New York, i v + 258 p .

Pilsbry, H. A. and E . G. Vanatta. 1905a. Mollusca of F l i n t and Caroline Islands, i n t h e c e n t r a l P a c i f i c . Proc. Acad. Nat. S c i . , Phila.,

V O ~ . 57: 291-293.

---

1905b. On some P a c i f i c C e r i t h i i d a e . Proc. Acad. Nat. Sci., Phila., vol. 57: 787-789.

Trelease, W . 1884. Botany of Caroline Island, - i n Report

...

o f t h e American Expedition t o

...

Caroline I s l a n d . . . Nat. Acad. S c i . , Mem.

NO. 2: 87-90.

Figure 2 . North s i d e of South Island on lagoon. Note t h i c k f r i n g i n g stand of Suriana along high-water l i n e . An occasional Pisonia o r Cordia t r e e i s found between t h e Suriana f r i n g e and t h e Cocos f o r e s t .

-

Figure 3 . East s i d e of Long I.sland with ~ o u r n e f o r t i a f r i n g e vegetation and s c a t t e r e d Suriana shrubs. P a t c h e s ~ e p t u r u s , Boerhavia, Portulaca a s s o c i a t i o n i n foreground,

Cocas

t o l e f t .

Figure 4 . North portion of Long Island as seen from t h e South Point of

I Nake Island. In t h e middle of Long Island a r e groves o f

I

Cordia and Pisonia with a dense f r i n g i n g cover o f Tournefortia

Figure 5 . Sooty Tern colony among and under dense vegetation on Bird I s l e t .