ATOLL RESEARCH BULLETIN May 15, 1959

ATOLL RESEARCH BULLETIN

NO.

63

Report on a v i s i t t o the Chesterfield Islands, September

1957

by F. Cohic

Issued by

THE PACIFIC SCIENCE BOARD

National Academy of Sciences--Na'cional Research Council Washington,

D.

C .

May 15, 1959

I l r , CHESTERFIELD

i )

Southwest Pacific area showing Chesterfield Islands

Report on a v i s i t t o t h e Chesterfield Islands, September 1 9 5 7 g by

F. Cohic Introduction

The most westerly French possessions i n t h e South P a c i f i c , t h e Ches- t e r f i e l d Islands, w e of i n t e r e s t t o zoo- and phyto-geography. They a r e a t the junction of s e v e r a l biogeographic regions, Australian, New Cale- donian and New-Hebridean. There wa.s a complete l a c k or" information on these islands, so it was obvious t h a t a v i s i t vould be f r u i t f u l . The v i s i t , unfortunately very b r i e f , only 4 hours, vas m d e possible by the invaluable cooperation of t h e French Navy. We wish t o express our g r a t i - tude f o r the opportunity t o t h e a u t h o r i t i e s i n charge, p a r t i c u l a r l y t o Admiral de Toulouse-Lautrec, and t o thank t h e o f f i c e r s and crew of t h e sloop Francis Garnier, who were very h e l p f u l t o us.

Location and h i s t o r y

-

The Chesterfield group i s located about 500 Ian. north-west of New Caledonia, i n the middle of t h e Coral Sea, and s t r e t c h e s between

158

and 159 degrees of Longitude East, and 19 and 20 degress Latitude South.

They include 11 i s l e t s , t h e main ones being t h e Chesterfield i s l e t s , Longue Island, and Avon, Renard and Bompton i s l e t s . Tneir t o t a l a r e a i s l e s s than 1000 hectares. This c o r a l group, halfway between Australia and New Caledonia, i s completely uninhabited and i s o l a t e d from shipping routes, and avoided a s a danger t o navigation.

The Chesterfield Islands have been a French possession s i n c e

1876,

and have oniy bern r a r e l y v i s i t e d by whalers and warships. The l a s t French vesr.?l ^w?r, t h e J.hunont d t U r v i l l e which surveyed t h e i s l a n d and prepared a tmp i n 1939.

Longue Island

This i s the p r i n c i p a l i s l e t on the V-shaped c o r a l r e e f , and was t h e only one v i s i t e d . It i s a narrow tongue of sand, approximately 1800 m.

long and 130 m. wide, and only

7

o r 8 m. above s e a l e v e l .

It seems t o be foiined of a s l i g h t l y r a i s e d platform, which has l a t e r been subject t? ;rind c m i o n . The various borings made down t o about

3.5

m. have r e r e a l e d a r e g c l a r s t r a t i f i c a t i o n of darker guano-bearing sand

&his r e p o r t i s an a b s t r a c t t r a n s l a t i o n by M.-H. Sachet of a French paper, issued here by permission of t h e au:hor. The o r i g i n a l , e n t i t l e d Rapport s u r une mission e:'feci:xe aux I l e s C h e s t e r f i e l d en Septembre 1957, 20 pp., Oct. 1957, was i s s u e c '.y the I n s t i t u t Fr-ancais dlOceanie, Noumea, New Caledonia, where t h e author i s an entomologist.

. .

l a y e r s a l t e r n a t i n g with l i g h t e r l a y e r s apparently f r e e of guano, which seems t o i n d i c a t e t h a t the surface has been repeatedly buried under new deposits probably by typhoons. No boulders o r l a r g e s i z e c o r a l debfjs were observed. Along t h e shore can be seen some s l a b s of sandstone- similar t o those seen i n t h e Loyalty Islands, a f a c t which may support the idea t h a t t h e i s l a n d i s r a i s e d . From the p o i n t of view of pedology, the s o i l i s made up of calcareous sands.of a r a t h e r coarse texture, with a t h i n brownish humus-bearing layer, often buried under sand. The i s l a n d has no f r e s h water.

Vegetation

Several p l a n t associations can be recognized:

a . ) On t h e sandy, very sunny e a s t slope Triumfetta procumbens forms l a r g e patches. Often associated with it, and even mixed with it Boerhavia

repens ( = Boerhavia d i f f u s a ) forms s i m i l a r patches. Other p l a n t s found in.this vegetation type a r e rounded patches of Coronopus i a t e g r i f o l i u s , a

few clumps of Portulaca l u t e a and many s c a t t e r e d p l a n t s of Didiscus sp.

-

( ~ m b e l l i f e r a e ) . Cassytha f i l i f o r m i s i s a l s o a s s o c i a t e d with t h i s vegeta-

--

t i o n type, covering p l a n t s of Triumfetta and Boerhavia with i t s s t r i n g - l i k e stems.

b . ) On the e a s t edge of t h e plateau t h e p l a n t s l i s t e d above a r e found again, but i n smaller numbers. The low vegetation i s made up mostly of grasses with Lepturus repens and Stenotaphnm sp. a s dominants, forming a dense harsh t u r f , more or l e s s continuous. There a r e only some clumps

of woody plants, mostly i n pure stands. The species are Sophora

z-

t o s a Scaovola s e r i c e a and Colubrina a s i a t i c a .

-, -

The shrubs, p a r t i c u l a r l y Sophora and Scaevola, a r e t h e p r i n c i p a l nesting s i t e s of f r i g a t e b i r d s and c e r t a i n boobies and thus determine t h e areas where guano i s deposited. This vegetation i s mostly dead with skeleton-like branches carrying t h e few twigs forming each of t h e numer- ous n e s t s . The accumulated droppings burn t h e leaves and branches and perhaps t h e excess of t o x i c s a l t s i n t h e s o i l d i s t u r b s t h e physiology of t h e p l a n t s which a r e slowly disappearing. By c o n t r a s t some i s o l a t e d clumps, o r some shrubs t o o low f o r t h e gregarious b i r d s t o n e s t on a r e remarkably luxuriant.

c . ) On t h e plateau, t h e vegetation i s mostly made up of grasses of a t l e a s t

5

species among which a r e Lepturus

w,

Stenotaphrum s p . , and Cynodon &act,ylon. The Lepturus cover is very h m o c k y i n t h e c e n t r a l p a r t ,

-.-- - ---

with deep hollows between t h e rounded clumps. Cynodon, o r Bermuda grass, i s very l o c a l and forms patches of very f i n e t u r f . DJumerous clumps of Achyranthes aspera a r e s c a t t e r e d here and there, with occasional p l a n t s

-

of a yellow-flowered Malvaceae, Abutilon

-

molle, and of tobacco, Nicotiana tabacum. On t h e west p a r t of t h e plateau, t h e beach morning-glory,

-- -

Ipomoea pes-caprae, forms a few patches.

;/%'he photographs kindly s e n t by the author show t h i s sandstone is t y p i c a l beach rock. Ed.

RECIFS ET I L E S C H E S T E R F I E L D

ILLS CHESTERflLLD

M O U I L L A G E DE L'ILE LONGUE

The i s l a n d a l s o c a r r i e s a dozen coconut palms which a r e growing r a t h e r poorly because of t h e v i o l e n t winds, b u t p a r t i c u l a r l y because of t h e b i r d droppings, which burn t h e fronds, and perhaps because of an excess of phosphate and n i t r a t e s i n the s o i l .

Flora

-

The f l o r a of Longue I s l a n d i s remarkably poor. ^{A l l} t h e species pres- e n t a r e s t r a n d p l a n t s of wide Indo-Pacific distri'oution, which a r e a l s o found on the c o r a l i s l e t s around New Caledonia.

L i s t of p l a n t s g o f Longue I s l a n d ANGIOSPEXMAE

Monocotyledonae G r d n e a e

Cynodon dactylon (L. ) Persoon Lepturus repens

pe or st.

) R . B r . Stenotaphrum sp.

Spinifex l i t t G e u s

Thuarea i n ~ [ F o r s t . ) R. Br

.

Palmae

Cocos nucifera L.

-

Dicotyledonae Amaranthaceae

Achyranthes aspera L.

Nyctaginaceae . , :,

Boerhavia repens L. ^{. .}

.

^..

Portulacaceae

Portulaca l u t e a Forst.

-

Lauraceae

Cassytha f i l i f o r m i s L.

Cruciferae

Coronopus i n t e g r i f o l i u s Spreng.

Leguminosae

Sophora tomentosa L.

Zygophyllaceae

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

A/Nomenclature and order adjusted somewhat from t h a t i n o r i g i n a l French version. Ed.

Rhamnaceae

Colubrina a s i a t i c a (L. ) Brongn.

Tiliaceae

Triumfetta procumbens F o r s t . Malvaceae

Abutilon molle Sweet _{- .} Umbelliferae

Didiscus

-

sp. (probably ... D.

-

cussonii ~ o n t r o l l z i e r ) Convolvulaceae

Ipomoea pes-caprae (L. ) Roth Solanaceae

Nicotiana tabacum L.

Goodeniaceae

Scaevola s e r i c e a Vahl

This f l o r a of 20 species i n 20 genera and

16

families is very poor.

A l l t h e species a r e c h a r a c t e r i s t i c of c o r a l strands; a l l a r e higher plants, no fern, moss o r l i c h e n were found. They a r e rrell adapted t o t h e h a b i t a t and r e s i s t a n t t o s a l t . Many have extensive r o o t systems, and fleshy, o r very hairy leaves. Most of them have f r u i t s o r seeds adapted t o dissem- in8tion by ocean currents (corky f r u i t s , long v i a b i l i t y ) o r by sea b i r d s ( s t i c k y o r spiny f r u i t s ) . Because of t h e extreme i s o l a t i o n of these

islands, few species have been a b l e t o reach them and e s t a b l i s h themselves.

During our s h o r t v i s i t t o Longue Island, a few p l a n t s were i n t r o - duced by the Service d t & r i c u l t u r e of New Caledonia. These were:

-

coco- nuts, Araucaria columnaris

orst st .

⁾ Hook., Sesbania g r a n d i f l o r a Pers

.

^and

Leucaena glauca TL.) Benth.

T e r r e s t r i a l fauna

-

The land fauna of Longue Island i s very small. There a r e no manunah, amphibians o r l a n d r e p t i l e s . The few groups represented a r e birds, t u r - t l e s

-

vhich come on land t o l a y eggs, s e a snakes, a few Arachnida and i n s e c t s .

A. AVES

The Chesterfield Islands, and p a r t i c u l a r l y Longue Island, a r e an important roosting and nesting s i t e f o r sea b i r d s , which explains t h e formation of guano deposits. A t t h e time of our v i s i t t h e p r i n c i p a l families represented were Sulidae and FregatiClae.

Sulidae

Sula s u l a rubripes Gould. the red-footed boobies n e s t mostly i n the shrubby vegetation of Sophora tomentosa and Scaevola s e r i c e a . The n e s t s

--

contain only one egg, of a greenish white c o l o r and covered with a chalky deposit.

Sula d a c t y l a t r a personata Gould. The blue-faced boobies n e s t d i - r e c t l y on the growld, without any twigs o r nesting material,

-

among the clumps of Triumfetta, Boerhavia and Lepturus. The nests contain two eggs b u t usually only one young.

Sula leucogaster Boddaert. The brown boobies a l s o n e s t on t h e ground b u t with a rudimentary n e s t of twigs usually protected from t h e

-

sun. The females l a y two o r t h r e e eggs, but usually only one young grows UP.

Fregatidae

Fregata a r i e l Gray. The l e s s e r f r i g a t e b i r d characterized by t h e

-

two white l a t e r a l markings of t h e male i s the most abundant. The n e s t i s usually perched on Sophora tomentosa shrubs and b u i l t of twigs more o r l e s s cemented by a hard substance. It contains only one chalky white egg.

k-egata minor

-

palmerstoni. The g r e a t f r i g a t e b i r d appears t o p r e f e r Scaevola s e r i c e a bushes, b u t sometimes a l s o n e s t s on grass clumps i n t h e

--."- ---

open.

Other seabirds of the family Laridae ( b r i n a e and Sterninae) were seen nesting on these low islands, but could not be i d e n t i f i e d .

B. CRUSTACEA 1. Isopoda-Oniscoidea

A t l e a s t two species a r e present and e s p e c i a l l y abundant under c o r a l boulders and p l a n t debris.

2 . Decapoda-Anomura

Coenobitidae

Coenobita p e r l a t a M.-E. This hermit crab i s one of t h e most obvious elements of the fauna of t h e C h e s t e r f i e l d Islands. This species of the t r o p i c a l Indo-Pacific a r e a i s adapted p e r f e c t l y well t o t e r r e s t r i a l l i f e and p r a c t i c a l l y never goes t o t h e sea except f o r egg laying. These ani- mals a r e of a b e a u t i f u l r e d color, with l i t t l e yellow tubercles bearing a black spine, and l i v e on t h e p a r t of t h e beaches above t h e reach of t h e highest t i d e s , and a l s o q u i t e f a r i n t h e i n t e r i o r , a s we had already

seen i n Makatea.

I n the Chesterfield Islands, t h e hermit crabs z r e exceedingly numer- ous and can be found during t h e day under c o r a l boulders, under d r i f t wood (pieces of canoes, bamboos, t r e e - f e r n s ) and p l a n t d e b r i s . The speci- mens observed were a l l of a l a r g e s i z e and l i v e d mostly i n s h e l l s of

Trochus and Turbo. They a r e mostly scavengers and clean t h e a r e a of a l l s o r t s of material ( f i s h , dead b i r d s , e t c . ) b u t a l s o e a t t h e plants, a s

-

sho5m by t h e i r droppings which a r e f u l l of p l a n t c e l l s and chlorophyll.

However, while they a r e a b l e t o s c a l e t h e coconut palms they do not ap- pear t o a t t a c k them and a r e not responsible f o r t h e i r poor condition.

C. ARACHNIDA j

I.

Acarina -.:

a. Sarcoptiformes Oribatei-Neoliodidae

A

specimen, probably of the genus Neoliodes was captured in the sand under the nest of the red-footed booby.

Oribatei-Galumnidae

Eleven specimens of a species in this group, characterized by wing- like lateral appendages were collected in guano-bearing sand in a booby nest.

Sulanyssus caputmedusae Trouessart. This species was kindly identi-

..

Pied by Dr. Jean Gaud of the Institut &'Hygiene du Maroc. Specimens were found in the feathers of Sula dactylatra and Sula suh.

- -- he-females

^are

viviparous, the males apparently are all heteromorphic.

b. Mesostigmata Gamasina-Laelaptidae

Many specimens were found in the litter or some frigates (Fregata ariel) brought back alive. This is a parasite of mammals, and as these

-

are apparently completely lacking on Chesterfield, the acarians probably were due to accidental contamination aboard ship or in the animal rais-

ing laboratory.

c. Ixodides

Argasidae . .

Ornithodoros capensis Neumann. This species was kindly determined by

Mr. J.

Rageau, medical entomologist and veterinarian for the Institut Francais dtOceanie. A specimen of this tick was captured on Sula dactylatra and several more found.later. This species is reported from

-

French 0 c k i a and from this host, for the first time. To o w knowledge it had been reported so far from Ascension

I.

in the Atlantic (Speiser

1909),

from peng~in nests (Snheniscus demersus) on the guano islands near the Cape (~e~unazn 190l), S t . ~auiI.-(NF!w Amsterdam group, Nuttall

1908)

and from the west coast of Australia on Eudyptula minor (~aylor

-

and Murray

1946).

In the Pacific, the species was known only from Micronesia (~uam, Kohls

1953)

and the Hawaiian Islands (~rench Frigate Shoals, Joyce 1953).

I t

is most likely that this species is very widely distributed and will be found in many islands where seabirds roost.

Van

Zwaluwen- burg

. . (1955) records an exuvium of Ornithodoros sp. Prom Canton Island;

quite possibly it is the same species.

It may be noted that the bite of this ticli is particularly painful for man.

2. Chelonetida

Several specimens belonging i n t h i s group wem c o l l e c t e d from l i t t e r under Sula d a c t y l a t r a .

- -

3. Araneida a . Sicaroidea Oonopidae

Scytopes sp. probably S. marmorata L. Koch. Two females were cox- l e c t e d . They feed on c i c a d a l i d s and small orthoptera.

b . Aranoidea Dionychae Thomisidae?

One specimen was collected on t h e beach.

Trionychae Agelenidae

One male and two females were found under a c o r a l boulder.

I n addition two species of Araneida could not be placed.

D. INSECTA 1. B l a t t a r i a

A t l e a s t two species are present, f r o m t h e egg cases found under dead wood.

2. Orthoptera a . Grylloidea Gryllidae Nemobiinae

One female, completely apterous was caught under a clump of Boerhavia.

b . Tettigonoidea Tettigoniidae

One female was caught i n a sweeping n e t . c . Acridoideae Acrididae

Ten o r s o specimens c a ~ ~ g h t on Cynodon dactylon and Lepturus repens.

Oligotomidae 3. Embioptera

-

Oligotoma oceanica Ross. A female specimen found i n seabird l i t t e r .

4.

Mallophaga 1. Amblycera

Menoponidae Menoponinae

Colpocephalum spineum Kellog ( d e t . M r . J. Rageau) hrom Fregata

s.

Myrsidea sp. from

-

Sula d a c t y l a t r a . 2. Ischnocera

P h i l i p t e r i d a e

Pectinopygus ()P- sulae ( h d o w ) on Sula s u l ? rubripes.

5.

Homoptera a. Fulgoroidea Araeopidae ( ~ e l p h a c i d a e )

Many specimens were swept from grasses. Sexual dimorphism i s strong, t h e males having t h e hind vings of an i r i d e s c e n t smokey black and the females transparent. These specimens b r i n g t o mind t h e genus Liburnia.

b

.

Cicadoidea Cicadellidae Euscelinae

Orosius sp. Two specimens were caught on grasses.

Cicadellidae Typhlocybinae

Abowt 60 specimens were caught on Boerhavia. The p l a n t i s l i t e r a l l y i n f e s t e d with t h i s small species and has many discolored yellowish spots.

Cicadellidae Jassinae

h i n o s c o p u s sp. One specimen.

6 .

Heteroptera Gymnocerata

Miridae Capsinae

Four specimens caught by sveeping.

Miridae Cylapinae

Ten specimens caught by sweeping.

Miridae Phylinae

Cmpylomma sp. Four specimens caught by sveeping.

Miridae Heterominae

Cyrtorhinus sp.? One specimen caught on Boerhavia.

a p a r a s i t e of the eggs of t h e Araeopidae.

Lygaeidae Lygaeinae O r s i l l i n i

Nysius sp. Numerous specimens caught on Boerhavia.

Very l i k e l y it i s

. , , . , .

7.

Coleoptera Only four species were collected.

Histeridae

Four specimens found in the droppings of Coenobita perlata.

Tenebrionidae

Gonocephalum

-

sp. Found under coral boulders and dead wood.

Undetermined Tenebrionidae. Three specimens found in same habitats.

Curculionidae

One specimen found by s~~eeping.

8.

Lepidoptera Pyralidae Pyraustinae

Hymenia recurvalis (Fabricius). One specimen was caught while fly- ing. The caterpillars most likely live on Achyranthes aspera.

9,

Diptera Hippoboscidae

One specimen was seen flying but could not be caught. It tras in- tensely black with a heavy and noisy flight, and

&

first sight would seen to belong in the genus Olfersia so common on frigate birds in the

--

Pacific.

ChloropiLae

Cadrema sp. About LOO specimens were caught on the guano around birds nests.

Calliphotidae

Lucilia sp. One specimen.

Dorilaidae (formerly Pipunculidae

1

Four specimens; probably a parasite of larvae of Araeopidae and Cicadellidae.

Sarcophagidae

Sarcophaga sp. One specimen on a dead

--

Sula sula.

Milichidae

Three specimens, much like Milichiella Lacteipennis (Loew)

.

Lonchaeidae

10. Hymenoptera Formicidae Formincinae

A few specimens found in guuano-bearing sand, under a stone.

Formicidae Pseudomyrimicinae

Numerous colonies found in sand under dead 1,~ood and in the bases of palm fronds.

This faunal list does not pretend to be complete, our visit to the island being much too short. However, it is sufficient to show the com- plete absence of certain important groups, which we particularly searched Por, such as Isoptera, Odonata, Culicidae, Tabanidae, Aphidae, Coccidae ,

Coccinellidae

and

Vespidae.

It is possible that during the wet season the arthropod fauna of the Chesterfield Islands is richer and more abundant than during our visit in a very

dry

period, but it probably is not very different from what we observed.

References c i t e d

Bedford (G.A.H.) 1934 - South African ticks. Part 1, Onderstepoort.

J. Vet. Sci.

2,

1: 49-99.

Degener

(0. )

and Gillaspy (E.

)

1955 - Canton Island South Pacific.

Atoll Research Bulletin 41.

Hewitt (J.) 1920 - Notes on the fauna of St. Croix Island. S. Afr. J.

Nat. Hist.,

2,

1: 98-112.

Hoogstraal 1956 - African Ixodoidea - Ticks of the Sudan. Dept. of the Navy. Bur. Med. Sure . , ^I,

^:

^{114-U5 and 864.}

Joyce 1953 - Insects records from French Frigate Shoal. Proc. Haw.

Ent.

-.-

Soc., 15 no. 1, . ^{13, March 1953.}

Kohls (G.M.) 1953 - Notes on the ticks of Guam, with the description of Amblyomma squamosum n. sp. (~carina Ixodidae). J. Parasit. 39,

3:

264-267,

Neumann (L.G.) 1901-- Revision de la faille des Ixodidae es. 4 Memoire.

Mem. SOC. 2001.

E'r.,

14; 2-3: 249-372.

Neumann (L.G.) 1907 - Note sur les Ixodidae recueillis dans les ilev de 1'0cean 1ndien par M. J. Stanley Gardiner. Trans. Linn. Soc.

e. ^{(2001) Ser.}

^{2, 32 (2) :}

^193-196.

Neveu-Lemaire (H.) 1938 - Traite dtentomologie medicale et veterinaire, p. 445, Vigot freres. Paris.

Nuttall (G.H.F.

)

and Warbwton (C.

₎

1908 - ^{On a} new genus of the Ixo- doidee together with a description of eleven new species of ticks.

Proc. Cmb. Phil. Soc., 14, 4: 392-416. (1907).

Speiser (P.G.E.) 1909 - Milben (~carina) Dtsch. Sudpol..Exped. X, zool., 2, 5: 597-603.

y ~ h e s e references do not pertain to Chesteflield, but are cited in con-

nection with the distribution of some of the animals listed.

Taylor (F.X. ) and Murray (R.E. ) 1946

-

Spiders, t i c k s and mites inclufiing t h e species hara~^ul t o man i n A u s t r a l i a and New Guinea. _-..- Serv.

Publ. Dept. Hlth. f k ~ s t .

--

Trop. Div. no.

6 ,

275 pj?.

Trommsdorff 1914

-

^{Beitrag zur} ICenntniss der i n ~ e c t s c h

-

Sudwest Africa verkommenden Zeclrenarten; Arch. Schif f s _-.---

.

^{1 . Tropenhyg}

. , ^{18: 7}

? l - 7 4 . Van Zmluwenberg (R.H. )

1955 -

The i n s e c t s and c e r t a i n other arthropods

of Canton Island. A t o l l Research Bulletin, no. 1!2, p . 2.