Tone (1970) 16: S-19. 5

S U B A N T A R C T I C C A M P B E L L I S L A N D

by Gordon S. M a x w e l l *

A B S T R A C T

From December 23 to January 26 1970 an expedit ion was con ­ducted to Campbel l Is land under the leadership of D r . H . Imshaug. A n account of the i s land ' s vegetation and of some of the vertebrates is g iven . The dwarf form of Gentiana antarctica was found on r idges . A subalpine aquatic moss, Drepanoclaulus fluitens, and Prasiola s p . , a l i chen from the super l i t tora l assoc iated wi th bird guano, are reported for the f irst time from C a m p b e l l I s land . Some new observations on Edyptes crestatus ( " rock hopper penguin" ) are given. A new nest ing l o ca l i ty for Phalacrocorax campbelli campbelli ( " C a m p b e l l Is land shag") is noted-. The rare P. carbo novaehollandiae ( " b l a c k s h a g " ) was

s ighted . A n unconfirmed s ight ing of Emberiza citrinella ("yellowhammer") i s recorded. T h e effect of introduced mammals (sheep, c a t t l e , and Norway rats) upon the native vegetat ion, rate of eros ion , and b ird l i fe is d i s ­c u s s e d . In part icular , the expedi t ion studied the subantarct ic terrestr ia l cryptogams, l imnology, seashore eco logy , phytoplankton, insec ts and vertebrates of the i s l a n d . Balanus campbelli was co l l ec ted from the sub l i t t o ra l fr inge.

I N T R O D U C T I O N

From December 23 1969 to January 26 1970 an expedit ion was conducted to Campbe l l Is land by D r . Henry Imshaug. The expedit ion was supported by the Nat i ona l Science Foundat ion , and equipped and control led by the United States Antarc t i c Research Programme at Operation " D e e p F r e e z e " headquarters, Chr i s t church . The expedi t ion was led by Dr . Imshaug (Michigan State U n i v e r s i t y ) . With him were Mr. R i chard C . Harris (graduate student, Mich igan State U n i v e r s i t y ) , Dr . Rudolph Schuster (Univers i ty of Massachuset ts ) , Mr. D a l e V i t t (graduate student, U n i v e r s i t y of Michigan) and Mr. Gary H e v e l (Smithsonian Inst i tut ion , Washington D . C . ) .

On December 17 1969, at 1500 hours the U . S . Burton Island, United States Coast Guard Cut ter , s a i l e d for the antarct i c . A t 1100 hours, on December 2 1 , the s h i p reached Campbel l I s l a n d . Our pos i t i on at this time was latitude 52° 3 0 ' S , and longitude 169° E -some 450 miles south of Dunedin , N . Z . ( F i g . 1).

C a m p b e l l Is land is a d i s sec ted vo l can i c cone, 42 square miles in area , which was mi ld ly g lac iated during the P le i s t o cene (Westerskov, 1960). It i s low in e l eva t i on , the ta l l e s t peak being Mt. Honey (1867 ft . ) .

•Department of Botany, University of Auckland.

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,1

North It. \ ^

r

Chatham It. p>

Stewart Is. • Bounty It.

5 0 ' " " •Auckland It.

•Campbell It.

' Emerald l«.

/ 190'

FIG. I: Campbell Island: locality

Its smooth h i l l s , broad open va l l eys and U-shaped fjords (Perseverance and North-east Harbours) are features of a g lac iated landscape. The i s land has a s teep , formidable coas t l ine and a rigorous c l imate , as the fo l l owing data ind i cate :

mean d a i l y temperature: 44° F . mean annual r a i n f a l l : 57 i n . mean no. rainy days per year: 328 mean no. days w i t h wind per year: 357 no. of gales per year: 76 mean wind ve loc i ty : 30 k t s . yearly no. of sunshine hours: 652

Members of the expedi t ion were accommodated and fed at the Meteoro logica l Station H o s t e l . The officer i n charge of C a m p b e l l I s l a n d , Mr. Peter J u l i u s , a l lowed the use of the Meteorological Stat ion f a c i l i t i e s ,

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FIG. 2: Campbell Island: place names. 1. North Cape 2. Mt. Faye 3. Mt. Fizeau 4. St. Col Ridge 5. Beeman H i l l 6. Moubray H i l l 7. Erebus Point 8. Northwest Bay 9. Dent Island 10. Yvon Villarceau Peak 11. Menhir 12. Mt. Dumas 13.Camp Cove 14. Garden Cove 15. Venus Bay 16. Fi lhol Peak 17. Monument Harbour 18. Jacquemart Island.

inc lud ing a heated room which was converted into a laboratory, plant press and drying room, and of f ice .

On January 26 the expedi t ion left Campbe l l Is land on H M N Z S Endeavour wh i ch s a i l e d eastwards for two days enab l ing p h y s i c i s t s to c o l l e c t geomagnetic d a t a , before a l t e r ing course to due south . McMurdo Stat ion , A n t a r c t i c a , was reached on February 4 and we were f lown back to New Z e a l a n d on a United States Navy C121 aircraft the f o l l owing night.

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V E G E T A T I O N

The i s land is windswept , tussock covered and t ree l ess . A s i n g l e specimen of Picea (spruce) grows on the i s l a n d at Camp C o v e . It is 9 ft . t a l l , s tunted, and its growth is mainly la te ra l , the a p i c a l growth being suppressed . The absence of trees could be caused by the charac ter i s t i ca l l y high winds and re la t ive ly low e levat ion of the h i l l s affording insuf f ic ient protection for normal tree development (Sorensen, 1951). T h i s account of the vegetation is based on that of Sorensen together w i th a number of my own observat ions .

Grassland

T u s s o c k grassland is the dominant plant formation. Poa litorosa, the pr inc ipa l tussock s p e c i e s , and Chrysobactron rossii, the seasona l l i l i a ceous herb, form the main a s s o c i a t i o n during the warmer months. So l i tary co lonies of C. rossii occur from just above sea l e v e l to the highest a l t i tudes (1800 ft) . From 1890 to about 1927 there was an abortive attempt to farm sheep on C a m p b e l l I s land . Sheep have markedly affected the vegetat ion. The C. rossii communities are a sheep- induced modi f icat ion. E a r l y records of the vegetation (Cockayne , 1903) show that there has been a dramatic increase in numbers of this plant over the past s i x t y years . Sheep avoid its bitter leaves and it has spread at the expense of Poa. The fern Polystrichum vestitum is abundantly scattered throughout the tussock at lower a l t i tudes together w i th the less common Blechnum procerum and the lycopods , Lycopodium fastigiatum and L . varium. The large , beaut i fu l , purple-headed compos i tes , Pleurophyllum speciosum and P. criniferum are two outstanding tussock s p e c i e s . They are attacked by the feral sheep and are becoming increas ing ly confined to places i n a c c e s s i b l e to sheep. Acaena sanguisorbae minor, Helichrysum bellidioides and the shrub Hebe benthami are important components of tussock. The blue flowers of the latter occur from October to May, whereas H. bellidioides produces white flowers throughout the year. The variable Gentiana antarctica is widespread in the tussock grassland from s e a - l e v e l to the highest peak (Mt. Honey, 1867ft . ) . ( F i g . 2). Sorensen reported that a dwarf form of G. antarctica was restr icted to lowlands and peat bogs. On a number of occas ions however, the author found these tiny plants on r idges .

Scrub

Dracophyllum scrub is a s t r i k i n g feature of the i s l a n d ' s vegetation. Dracophyllum scoparium (with erect , l inear , acute leaves) occurs with and dominates D. longifolium (with wider , curved leaves) . The scrub f lourishes between sea - l eve l and 600 feet. In protected va l l eys it forms inpenetrable s tands , movement through w h i c h is almost imposs ib le . U s u a l l y this scrub

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forms a c l o sed community wi th very l i t t l e undergrowth. Mosses and l ichens ex i s t as d i s t i n c t i v e s o c i e t i e s , carpet ing the ground or ep iphyt i c upon stems and branches.

On some s lopes dense patches of Coprosma - Myrsine scrub e x i s t . T h i s scrub was found to be part icular ly w e l l developed on the eastern s lopes of P u i s e u x Peak near South E a s t Harbour. Here , as in some other areas , it formed a t rans i t ion zone between Dracophyllum scrub in the val ley bottoms and tussock above. Myrsine divaricata and the two Coprosma s p e c i e s , C. cuneata and C . ciliata occur t y p i c a l l y as low compact bushes . The common fern, Polystrichum vestitum i s a l s o abundant. The green and brown of the scrub spec ies and the red brown fronds form a dense patchwork of f o l iage .

Bogs and related communities

Carex appressa communities are present in parts of the wetter lowland tussock areas. These Carex f lats are often assoc ia ted w i th underground streams and tend to be more common near the c o a s t . Blechnum procerum, the ubiquitous Helichrysum bellidioides and the prostrate, creeping Coprosma pumila occur w i th Carex as subordinate spec ies in this sedge community.

Peat moors are character ised by a th i ck , spongy, perpetually wet deposit of peat, and by cush ion plants s u c h as Oreobolus pectinates and Gaimardia ciliata. T h e white flowered Phyllache clavigera, s m a l l plants such as Drosera stenopetala, Epolobium confertifolium, Acaena sanqpiisor-bae and Coprosma pimula, w i th i t s orange drupes, are a l s o common moor s p e c i e s . Celmisia vemicosa f l our ishes on the lowland moor where s p e c i ­mens are larger than at higher a l t i tudes . The orchid Lyperanthus antarctica appears i n the summer and Gentiana antarctica is present throughout the i s land be ing part i cu lar ly evident on the moor.

Sphagnum bogs are conspicuous communities on wet tussock s l o p e s . Dominated by Sphagnum these deep moss beds are w e l l developed on the west of Tucker Cove va l l ey and the north of Camp Cove v a l l e y . Astelia subulata, Lycopodium fastigatum, Hymenophyllum multilidum, Blechnum pennamarina and the rush Juncus scheuchzeroides are minor const i tuents of the Sphagnum bog.

Subalpine rock communities

C r a c k s and crev ices in summit rocks and rocky outcrops contain suf f i c ient s o i l to support a number of d i s t i n c t i v e p lants . T h e s tate ly umbelliferous herb, Anisotome antipoda is perhaps the most impressive plant of th is habitat . The confinement of A, antipoda to these i n a c c e s ­s i b l e l o c a l i t i e s can almost cer ta in ly be attributed to sheep graz ing .

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Ranunculus pinguis, Celmisia vernicosa and Pleurophyllum speciosum accompany A. antipoda, e s p e c i a l l y in wind-protected c r e v i c e s . These large herbs require more s o i l than most crev ice p lants , often growing where deposi ts are over a foot deep. The ferns, Polypodium billardieri pumilum, Hymenophyllum and Asplenium obtusatum, can ex i s t in a few mil l imetres of s o i l held in very s m a l l c r a c k s . C u s h i o n formers such as Colobanthus and Phyllachne and numerous mosses and l i chens surv ive on l i t t l e more than bare rock. Some of the best examples of the sub-a lp ine dwel lers were found a long L y a l l r idge.

Aquatic plants in subalpine tarns

The aquatic moss Drepanoclaulus fluitens completely dominates a number of s m a l l tarns in the A z i m u t h - F a y e - F i z e a u region but has not been mentioned in previous l iterature on the i s l a n d .

Maritime vegetation

Of the herbs, Anisotome latifolia and Stilbocarpa polaris are the most important but have decreased in number s ince C o c k a y n e ' s v i s i t in 1903. A l o n g w i t h Pleurophyllum speciosum and P. criniferum they tend to be restr icted to i n a c c e s s i b l e rocky bluffs and c l i f f s .

Hebe elliptica is a t y p i c a l maritime shrub and unl ike Dracophyllum, i s confined to c o a s t a l l o c a l i t i e s .

Of creeping habit upon rocks are the red-tinted Tillaea moschata and the ye l low flowered Cotula lanata. Both these spec ies and a s m a l l sedge, Scirpus aucklandicus are very abundant. Ranunculus subcaposus is common in the wetter c o a s t a l tussock areas .

Of the ferns, Blechnum discolor occurs throughout the maritime zone and Asplenium obtusatum frequently festoons the steeper faces of rocky c l i f f s .

Several important c o a s t a l plants are assoc ia ted wi th a n i m a l s . Poa annua and Stellaria media are two introduced plants whose presence i s consequent upon destruct ion of the larger tussock , Poa litorosa, by elephant s e a l s . Herds of this large marine mammal f latten the vegetation and create large w a l l o w s . Abandoned wal lows become ponds and habitats for water plants such as Callitriche antarctica and Montia fontana. The destruct ion of native vegetation by elephant sea l s and the establ ishment of introduced plants , part i cu lar ly grasses , is evident at the head of Perseverance , North-east and Monument harbours. On the western shores of S ix Foot L a k e abandoned wal lows abound, and many are concealed by regenerating t u s s o c k s . Extreme care is necessary when w a l k i n g through this maze of hidden ponds. Poa ramosissima grows w e l l on the steep c l i f f s at Courre jo l l es P e n i n s u l a and elsewhere on the northern coast ,

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part i cu lar ly where the mollymawks nest. It i s l i k e l y that the growth of these plants is enhanced by the bird guano. Prasiola sp., a green l i c h e n resembling Viva, i s character i s t i c of the super l i t t ora l zone frequented as it i s by seab i rds . It covers much of the super l i t tora l rock near the mouth of Perseverance Harbour. T h i s l i chen has not previously been reported from C a m p b e l l I s land .

V E R T E B R A T E F A U N A

Marine Mammals

Mirounga leonina (elephant seal ) i s perhaps the conspicuous feature of the more protected shores of Campbe l l Is land . Its wa l l ows are t y p i c a l l y 12-15 ft . long x 4-5 ft . wide x 4 ft . deep, and abandoned wa l l ows are often f i l l e d w i th brown peaty water . These b u l k y , lumbering animals which can at ta in a length of 18 feet are gregarious and one frequently f inds a s o c i a l group compr is ing a b u l l and a harem of f ive or more c ows . They spend most of the day s l e e p i n g together in w a l l o w s . When approached by humans they do l i t t l e more than open their mouths and d i sp lay their teeth (which are commonly damaged) in a threatening att i tude. The male is d i s t i n c t i v e w i th i ts large proboscis w h i c h is distended when the beast is d is turbed . Inefficient on land, they move to the sea w i th gross lumbering and s l i d i n g movements. T h e i r habits of w a l l o w i n g , lumbering and l y i n g in the sun produce extensive open areas a long the tussock fr inges . T h i s may be seen c l ear ly a long the shores of Perseverance and North-east harbours.

Another marine carnivore , Neophoca hookeri (sea l ion) comes ashore on Campbel l I s land . L e s s common, and far more ac t ive and aggressive than the elephant s e a l , the sea l i on spends more time i n the sea than it does on land . T w o males and a female were d a i l y observed at the wharf between December 1969 and January 1970. They f ished regularly in the extensive sub l i t t o ra l Macrocystis pyrifera beds a long the inner shores of Perseverance Harbour. More s k i l l e d on land than the elephant s e a l , the powerfully constructed sea l i on can at ta in speeds of around 6 m.p.h. over tussock . Sexua l dimorphism is obvious in colour and b u i l d . The male has a dark brown coat of hair which is p a r t i ­cu lar ly th ick around the neck and shoulders . The female is l ight brown and smal ler . On severa l occas ions a large b u l l was seen to ra ise i ts head and shoulders from the Macrocystis zone and sni f f the air in search of the female. Once located, the female was v igorously pursued over tussock around the meteorological s tat ion and later across the harbour.

A s m a l l number of fur s e a l s (Aretocephalus forsteri) inhabit the i s l a n d . On December 31 1969 the author observed three of these s e a l s on

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rocks at the mouth of Perseverance Harbour. They were brown and approx­imately seven feet long. A s o l i t a r y animal was noticed at Penguin B a y on

January 6 1970.

The s lender sea leopard (Hydrurga leptonyx) v i s i t s Campbe l l Island ( B a i l e y , 1962) but the author did not observe any.

Birds

The general account and orders is based on that of Westerskov (1960) and generic and spec i f i c names fol low those of F a l l a (1966)- T h e author's observations are ind i ca ted .

SPHENISCIFORMES

Aptenodytes patagonicus ( k i n g penguin) . T h i s large penguin is a rare straggler to Campbe l l I s land , probably from Macquarie I s land . A so l i tary bird v i s i t e d the i s l a n d in mid January 1970. The bird came ashore br ie f ly near the wharf at Perseverance Harbour, then headed back to s e a .

Megadyptes antipodes ( ye l l ow-eyed penguin). A s m a l l number of birds breed on the i s l a n d , Westerskov estimates approx. 200 pairs in a few areas (Perseverance Harbour, North-east , South-east and Monument Harbours, and North-west B a y ) . U n l i k e the no isy rockhopper penguin, the yel low-eyed penguin is quiet . The author observed a so l i tary nest ing pair at South-east Harbour on January 13.

Eudyptes sclateri (erect-crested penguin). A s m a l l number of birds breed on the i s l a n d . S ingle pairs and s m a l l co lon ies are scattered amongst the huge rockhopper co l on ies . On January 6 three pairs were observed at Penguin B a y .

Eudyptes crestatus (rockhopper penguin). This small , noisy penguin i s the most abundant bird on the i s l a n d . (Two to three mi l l i on ind iv idua l s are present.) Large co l on ies , conta in ing thousands of b i rds , occur a long the exposed and i n a c c e s s i b l e western coast . The Penguin B a y colony was v i s i t ed on January 5 and 6. There were severa l thousand nest ing pairs in the co lony, many with large fluffy mouse-grey c h i c k s . Down covered c h i c k s two-thirds the s ize of the adult birds were s t i l l brooded by the parents. The loud braying cr ies of these birds were incessant throughout the day and night . Desp i te their c o l o n i a l habit , nest ing pairs occupy a s m a l l but aggress ive ly guarded territory. Straying c h i c k s are voca l l y threatened, then attacked if they f a i l to stay in their own territory. Parents seldom rest during the nest ing period. While one parent searches for food at sea , the other main^ ta ins a constant watch for the southern skua or sea hawk. T h i s large seabird of prey c ru ises overhead, descending to feed upon unguarded food scraps and attack stray penguin c h i c k s . On several occasions it was seen

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in " d i v e - b o m b e r " attacks on unwary c h i c k s . A d u l t s unite de fens ive ly during a t tacks , uttering aggressive c r i e s wi th beaks upturned, but once these are over they return to the task of keeping fellow penguins out of their territory. A group of 10 or 20 adults hopping in sequence from rock to rock along accepted pathways to the sea was a famil iar s ight in the co lony.

P R O C E L L A R I I F O R M E S

Diomedea exulans exulans (wandering a lbatross ) . T h i s bird i s rare , a few pairs breeding in the Moubray H i l l area.

Diomedea epomophora epomophora (southern royal a lbatross ) . T h i s i s undoubtedly the most outstanding bird on the i s l a n d . C a m p b e l l Is land is the main breeding ground in the world for th is spec i e s . In the late 1950's the to ta l breeding population was estimated to be 4,600 pairs (Westerskov), There i s no evidence of a dec l ine (Mr. D a v i d P a u l , Senior Meteoro log i ca l Observer on Campbel l Is land 1969-70 and Meteorological Observer 1965-66, 1967-68 and the author's observations. ) One egg measuring 126 x 78 mm. is la id per season . E g g mortality is l ow, 75 percent hatching and reaching the nest l eav ing stage . The high winds on the i s land ass i s t the royal albatross i n takeoff. A leg injury resul t ing from a misjudged takeoff i s perhaps the most ser ious and common problem of th is large b i r d . Once airborne the royal a lbatross , l i k e other members of the Diomedeidae, d i sp lays an almost perfect g l id ing f l ight . The strong winds are used to the f u l l ; the bird having the entire southern ocean in which to search for food. The cry i s p l a i n t i v e , reminiscent of a s m a l l c h i l d in d i s t r e s s .

Diomedea melanophris impavida (black-browed mollymawk) and Diomedea chrysostoma (grey-headed mollymawk). The mollymawks are smal ler than the albatrosses but just as spectacular . Both s p e c i e s nest together in their thousands on Courre jo l les P o i n t . Much of th is s teep , 800 ft . h igh , rocky peninsula is i n a c c e s s i b l e to man. It is here, on s l opes which are l i t t l e l ess than sheer c l i f f s , that the mollymawks bu i ld their cone-shaped flat-topped nests . The nest materials are peaty s o i l and plant remains. C h i c k s of the two-mollymawk spec i es cannot be d i s t i n ­guished . Both have a fluffy grey down and b lack beak. The adult b l a c k -browed mollymawk is pure white except for its b lack wings and mantle, dark grey t a i l , and a region of smokey grey about the eyes . T h e beak is ye l l ow , but pink d i s t a l l y , and the feet are pale b lue . ( F a l l a et. al.,1966). A dark grey head and neck and a spectacular beak with a dark central s t r ipe , edged above and below with deep ye l l ow , d i s t ingu ishes the grey­headed mollymawk (Fal la et.al . ) . The two spec ies nest c l o se together w i th 3 to 10 feet between nests at Courre jo l les and 2 to 3 feet in the North Cape co lony . F e w nests were seen to be unoccupied, which perhaps i n d i -

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cates low mortality. The different spec ies do not segregate with in tin-co lon ies . Although nests are c l o se together, each nest ing pair maintains: and protects a s m a l l territory around its nest .

Phoebtria palpebrata ( l ight-mantled sooty a lbatross ) . T h i s i s a beauti ful bird whose entire plumage is dark except for a smal l h a l f - c i r c l e of white feathers on the e y e - l i d . The main body plumage i s l ight pearly brown, shading to intense dark brown on the top and the s ides of the head, wings and t a i l . T h e beak i s b l a c k . (Fal la et.al.). It nests in s m a l l groups or s i n g l y on steep s lopes and c l i f f s . On December 29 1969 a so l i tary nest ing bird was found on the northern s ide of Beeman H i l l . It was s i t t i n g on a mound-shaped nest conta in ing one egg measuring 6 x 2.5 cm. A number of birds were nest ing around Perseverance Harbour.

Macronectes giganteus (giant petrel ) . T h i s large, mottled, grey-brown bird was observed regularly in Perseverance Harbour. Here 20-30 of these scavengers c leaned the meat off an elephant s e a l ' s ca r cass in one week. T w o d i s t i n c t i v e features of the giant petrel are i ts heavy beak wi th a s ing le elongate nasa l tube (Fal la et .al . ) , and i ts method of takeoff . T h e adult runs with wings f lapping a long the water surface for about 100 yards before becoming airborne. The resultant sound i s reminiscent of d istant machine gun f i re . On January 8 1970 about ten nest ing birds wi th c h i c k s were seen in the tussock near the western shore of Six Foot L a k e . Three young birds were examined. A l l were c l a d in a dark grey down and had several mature feathers on their w i n g s . The nests were rough low mounds of s t i c k s , peat and tussock .

Daption capensis (cape pigeon). T h i s was f irst seen in subantarct ic waters from the U . S . Burton Island, and was a l so commonly observed in Perseverance Harbour. It was a constant companion of H M N Z S Endeavour throughout the entire journey to the A n t a r c t i c .

Puffinus griseus (mutton bird) . T h i s spec ies was only seen in Perseverance Harbour where i t s occurrence was infrequent.

P E L E C A N I F O R M E S

Phalacrocorax campbelli campbelli (Campbel l Island shag). This is a common resident breeding bird (Westerskov). It i s very tame and frequents Perseverance Harbour. A previous ly unreported colony of f ive birds was observed nest ing near the top of a 600 ft . c l i f f on the northern coast between Courre jo l les Point and North Cape (January 2 1970). One adult w i th s i x c h i c k s was observed near Garden Cove on December 27 1969. The adult shag and a red-bi l led g u l l together prevented a skua from at tack ing the shag c h i c k s .

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P. carbo novaehollandiae (b lack shag) . T h i s is a rare straggler to C a m p b e l l Is land, poss ib ly from Stewart Is land or Tasmania (Westerskov). Both Mr. Dav id P a u l and the author saw a so l i tary B l a c k Shag near S ix Foot L a k e on severa l separate o c cas i ons .

AN ATI FORMES

Anas superciliosa (grey-duck). T h i s spec ies is a rare breeding b i r d . A n i n d i v i d u a l was s ighted in the Camp Cove stream on December 27 1969.

CHARADIIFORMES

Catharacta lonnbergi (southern skua) . T h i s is a conspicuous bird on Campbe l l I s land . A n aggressive scavenger and predator, it i s ex tens ive ly distr ibuted on the i s land and frequents both coast and r idge. N e s t i n g b irds with chestnut-brown c h i c k s were observed at Penguin B a y , on the northern s lopes of Mt. P a r i s , and on the F a y e ridge during January 1970. About 12 skuas searched cont inual ly for food scraps near the wharf at Perseverance Harbour.

Lams dominicanus ( b lack -backed gu l l ) . A sporadic co l on is t on the i s land of which no nests were s ighted though one or two birds were regu­lar ly noticed in Perseverance Harbour. Westerskov considers that the birds are l imited to a few s m a l l scattered co lonies by a lack of nest ing s i t e s .

Lams scopulinus ( red -b i l l ed gul l ) . The i s l a n d has a few nest ing b i r d s . F a l l a et .al . , 1966 d i s t i n g u i s h , but do not name, a subantarct ic race with a shorter stouter beak and s l i g h t l y darker plumage than other N . Z . populat ions . In nest ing habit the race is a l s o d i s t inc t ive us ing cav i t i e s rather than exposed s i t e s . Several R e d - b i l l e d gul ls were s ighted in Perseverance Harbour during January 1970. A s ing le pair was nest ing in a cav i ty overhung by Dracophyllum scrub on the seaward s lope of Beeman H i l l .

S tema vittata bethunei (Antarct ic tern). T h i s spec ies was commonly seen in Perseverance Harbour and, according to Westerskov, nest there and below Moubray H i l l .

PASSERIFORMES

Turdus ericetomm (song thrush), and T. memla (blackbird) are rarely met as breeding birds on C a m p b e l l I s l a n d , both probably being se l f - introduced from N . Z . On December 24 1969 the author saw a blackbird in Tucker V a l l e y .

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Prunella modularis occidentalis (hedge sparrow). T h i s b ird was frequently encountered in the Dracophyllum s crub .

Emberiza citrinella (yel low hammer), T h i s spec ies i s not known to occur on the i s l a n d . On December 24 a s i g h t i n g was made, but not c o n ­f irmed, in the Dracophyllum scrub of T u c k e r V a l l e y .

Stumus vulgaris ( s tar l ing) . T h i s bird is rare. T w o ind iv idua l s were seen near Venus B a y early in January 1970.

Exotic mammals: sheep, cattle and rats

Sheep have had a marked effect on the vegetation of Campbe l l I s land . They have grazed upon this natural tussock grassland for over seventy years . A s w e l l as modifying the vegetat ion, sheep have accelerated erosion and may be having a minor effect on the b i rds . Many spec ies have become very scarce s ince C o c k a y n e ' s day (1903) and are now restricted to p laces i n a c c e s s i b l e to sheep (Sorensen, 1951). Pleurophyllum speciosum, P. criniferum, P. hookeri, Stilbocarpa polaris, Anisotoma latifolia and the subalpine A. antipoda, are obvious examples of plants having th is now restr icted d i s t r ibut i on . Poa toliosa and Stilbocarpa polaris, once common components of the maritime vegetat ion, are rare today.

Other spec ies mentioned by Cockayne no longer ex i s t on the i s l a n d . Danthonia australis and Sonchus asper, the snow t h i s t l e , have been destroyed by sheep. They may occur on the s m a l l offshore i s l a n d s of Dent and Jacquemart.

P l a n t communities too have been a l tered . Poa toliosa has been replaced as the dominant tussock by P . litorosa and Danthonia flavescens i s no longer an important tussock s p e c i e s . Communities of Chrysobactron rossii, an unpalatable l i l y , w h i c h have spread at the expense of the tussock grasses , represent an induced formation (Sorensen).

Not a l l sheep-induced changes are decreases or l o s s e s , however. Some plants appear to be in equ i l i b r ium, whi le others are increas ing in numbers; Ranunculus pinguis and R. subscaposus (ranging from the coast to 1000 ft.) are eaten, but s u r v i v i n g . Sheep predation upon native spec i e s has fac i l i ta ted the spread of some introduced p lants , e s p e c i a l l y grasses such as Poa annua and Lolium perenne (rye-grass) . However, some introduced spec ies s u c h as Dactylis glomerata are prevented by sheep from spreading (Sorensen).

The low, compressed growth form of Myrsine divaricata can be attributed to attacks by sheep (Sorensen).

T h e increas ing s carc i ty of certain plant spec i e s , the disappearance of others, changes i n plant communities and the increase in introduced grasses can be attributed to sheep graz ing . The Wi ld l i f e Sect ion of the

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N . Z . Department of Internal Af fa i rs is currently s tudying the effects of sheep on Campbel l Is land vegetat ion. The i s land has been d iv ided into two halves by a fence between T u c k e r camp and St. C o l r idge. A l l sheep were shot in one half and al lowed to graze in the other.

Large patches of Campbel l I s land ' s h i l l y terrain show the scars of accelerated eros ion. Once exposed, the soft peaty top s o i l i s readi ly removed by strong moisture-laden w i n d s . E x t e n s i v e areas of eros ion were observed on the southern s lopes of Mt. Honey and a long L y a l l ridge towards South Water B a y . Widespread grazing on these wind swept s lopes and consequent further eros ion may make the s low natural regeneration d i f f i c u l t . Destruct ion of the sheep is c l e a r l y des irable now, but may already be too late to avert the continued erosion in certain areas .

Sheep are present along the eastern region of Courre jo l l es point. A s they walk through the co lony , they may contribute to c h i c k mortality in the mollymawk colony by c a u s i n g adults to leave their nests tempor­a r i l y . Unprotected eggs are thus exposed to attacks by the s e a hawk (skua) . T h i s factor, l i k e that of rats in the penguin co lon ies , is probably of minor s i g n i f i c a n c e .

One or two s m a l l herds of fera l catt le (Ayrshire breed?) roam on the i s l a n d . On January 6 1970, twenty were counted in the Menhir area . L e s s severe in mode of grazing and fewer in number, catt le are u n l i k e l y to adversely affect the vegetation. They are regarded as an emerging food supply (Mr. Peter J u l i u s O I C , Campbe l l Is land) .

The Norway rat (Rattus norvegicus) is regularly caught at the meteorological s ta t i on . It is a predator on birds eggs. Westerskov (1960) reports the rat in penguin c o l o n i e s , wi th some evidence o'f egg s u c k i n g . B a i l e y (1962) suggests that they are probably responsib le for the v i r t u a l e l iminat ion of Campbe l l Is land as a breeding place of smal l petrels and shearwaters .

R E S E A R C H P R O J E C T S

T h e main aim of Dr . Henry Imshaug's expedi t ion was to study the terrestr ia l cryptogams of the subantarct i c . D r . Imshaug was a s s i s t e d by Mr. R i c h a r d C . H a r r i s , in an extensive study of the l i chen f lora and eco logy. D r . R . Schuster co l l e c ted l iverworts and Mr. D a l e V i t t mosses . Mr. Gary H e v e l , an entomologist from the Smithsonian, s tudied the insect and other arthropod fauna.

My own work comprised:

(a) Water-sampling from various l o c a l i t i e s i n c l u d i n g seaward and landward ends of S ix Foot L a k e , a Carex appressa bog, lowland peat moor

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and upland bog, a Sphagnum bog, a stream, and a subalpine t a i n . Water temperature, p H , and vegetation were recorded and peat samples were taken. Water samples were preserved for chemica l a n a l y s i s at A u c k l a n d U n i v e r s i t y .

(b) Seashore ecology. Shore scapes were examined at the eastern and western ends of Perseverance Harbour, Northeast and Southeast Harbours and Penguin B a y . The absence of barnacles in Perseverance Harbour has been mentioned as a notable pecul iar i ty of the Campbe l l Island shore (Morton and M i l l e r , 1968). On January 16 the author found the barnacle , Balanus campbelli, near the Durvillia antarctica zone on the south shore, at the eastern end of Perseverance Harbour. T h i s large barnac le , approximately the s i z e of Elminius plicatus, was not abundant, and many were submerged even at low t ide . It was absent from the more protected inner harbour and may be a surf s p e c i e s . The barnacle was not found on the very exposed northern shore at Penguin B a y .

(c) Several s m a l l projects were a l s o carr ied out inc lud ing a search for Caepidium antarcticum, phytoplankton sampl ing in Perseverance Harbour and from severa l s tat ions between Chr i s t church and C a m p b e l l Island and co l l e c t i on of fungi and f lowering plant material (pressed, preserved and some l i v i n g endemics) .

Since 1946 Campbe l l Is land has been a weather stat ion administered by the N . Z . Aerodrome S e r v i c e s , Department of C i v i l A v i a t i o n , and today, the Min i s t ry of Transport . The Meteoro log ica l s tat ion is staffed by nine men: four of whom are meteorological observers, the others be ing an ionosphere observer, DSIR t e c h n i c i a n , cook, mechanic and OIC. T h e team is re l ieved annual ly . A s w e l l as making weather observations and reports a cons iderable number of c l i m a t o l o g i c a l , ionospheric and s e i s m o -l o g i c a l data are recorded by the staff . Several in the team are a l s o s k i l l e d amateur orn i tho log is ts . A government or university-supported b io log i s t would be des i rab le in this team.

P O S S I B I L I T I E S F O R F U R T H E R R E S E A R C H

Research which is yet to be done inc ludes-

(a) Sophist i cated e c o l o g i c a l s tudies of the vegetation.

(b) Marine a lga l ecology — e s p e c i a l l y of the sub l i t t o ra l communities in Perseverance Harbour.

(c) A study of the cat t le (e.g. physiology and genetics of the feral herd).

(d) Ornithology: further studies of the royal albatross and mo l ly ­mawks (behaviour, gut contents etc . ) .

(e) Marine mammalogy: sea l i o n s , elephant sea l s and fur s e a l .

(f) F i s h s t u d i e s .

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A C K N O W L E D G E M E N T S

The N a t i o n a l Science Foundat ion in Washington D . C . , U . S . A . and United States Antarc t i c Research Programme in Chr is tchurch for f inanc ing and equipping the expedi t ion .

US C o a s t Guard , R N Z Navy and US Navy for air and s e a transport .

The author wishes to thank, in part icular the f o l l owing : Pro fessor V . J . Chapman and Professor Henry Imshaug for the opportunity to p a r t i c i ­pate in the expedit ion .

Members of the expedit ion for a s s i s t a n c e general ly , and to D r . Imshaug and D r . Schuster (determination of Prasiola sp . ) , and D a l e V i t t (determination of Drepanoclaulus) in part i cu lar .

Mr . Peter J u l i u s and h is personnel on Campbe l l Is land for sp lend id a s s i s t a n c e and cooperation.

Professor J . Morton and D r . B . A . F o s t e r (Department of Zoo logy , Un ivers i ty of Auck land) for the ident i f i cat ion of Balanua campbelli.

T h e Commander of US Burton Island for ass i s tance w i th phyto-plankton sampl ing between Chr i s t church and Campbe l l I s land , and the Commander of H M N Z S Endeavour lot transporting the Campbel l Is land material to A u c k l a n d .

Mr. Donald Laurenson for the c r i t i c a l reading of the manuscript .

R E F E R E N C E S

B A I L E Y , A .M. , 1962 SORENSEN, J . H . C O C K A Y N E , L . 1903

F A L L A , R.A., 1966 SIBSON, R . B . , T U R B O T T , E . G . MORTON, J . E . , M I L L E R , M.C. SORENSEN, J . H . , 1951 O L I V E R , R . L . WESTERSKOV, K . J . 1960

Subantarctic Campbell Island. Proc. Denver Museum of Nat. Hist. 10.

A botanical Excursion during Midwinter to the Southern Islands of N . Z . Trans. N.Z. Inst. 36: 225-333. 'A Fie ld Guide to the Birds of New Zealand' . Collins, London.

1968 'The New Zealand Sea Shore'. Collins, London.

Botanical Investigations on Campbell Island. D.S.l.R... Wellington: Cape Expcd. Ser., Bull. 7.

Birds of Campbell Island. Dept. of Internal Affairs, Wildlife Publ. 61: 1-83.

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