Ornithological observations at Gough Island in 1979, 1980 and 1981

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40 S. Afr. T. Antarkt. Nav., Deel 12, 1982

Ornithological observations at Gough Island in 1979, 1980 and 1981

A.J. Williams*

Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7700 and M.J. Imber Wildlife Service, Dept. of Internal Affairs,

Private Bag, Wellington, New Zealand

A bibliography of ornithological visits and a checklist of the birds of Gough island are followed by a ~ystematic account of incidental observations made on birds during expeditions to Gough Island during November 1979, October-November 1980, and September 1981. During these expeditions 33 species were observed of which six were recorded at Gough Island for the first time. The populations of Eudyptes chrysocome and Diomcdea cxulans were censused. Incidental notes include weight and mensura/ data and observations on prey consumed.

'n Bibliografie oor ornitologiese besoeke en 'n oorsiglys van voels van Gough-eiland word gevolg deur sistematiese versfag van toevallige observasies van voels tydens ek~pedisies na Gough-eiland gedurende November 1979, Oktober-November 1980, en September 1981. Tydens hierdie ekspedisies is 33 spesies waargeneem waarvan ses vir die eerste keer vir Gough- eiland aangeteken is. Populasies Eudyptes chrysocome en Diomedea exulans is gesensus. Toevallige observasies sluit in mates en gewigte en observasies met betrekking tot prooi inname.

Introduction

Gough Island (40°S, i0°W) is situated in the South Atlantic Ocean s0me 2 800 km from southern Africa and 3 200 km from South America and lies in sub-Antarctic waters about 350 km south of the subtropical convergence. Ornithologists have visited the island during some 22 expeditions and their findings have been documented in 37 publications (Table I). In all ~4 species of birds have been recorded at the island (Table 2). By ecological grouping these are: sea birds -36 species of which 17 are known to, and four may, breed and 13 are visitors or vagrants; waterside birds - five species. all vagrants; and landbirds (sensu faro)- four species of which two breed and two are vagrants.

This paper reports ornithological observations made during brief expeditions to the island from 30 October to 12 November 1979.21 October to 19 November 1980, and 6 to 26 September 1981 by members and guests of the Percy Fitz- Patrick Institute of African Ornithology. These accounts are

Table I

Ornithological visits to Gough Island.

Name of e":pedition/

observer Year of visit Period ashore Publications

'Telegraph' Een 1869 31 May La yard (1869), Brooke (1979)

Corner 1888-1889 Aug22-Jan23 Allen (1892), Verrill (1895)

'Scotia' 1904 April22 Clarke (1905), Clarke (1913), Bruce ( 1905)

'Quest' 1922 May27-June1 Lowe (1923), Wilkins (1922), Wilkins ( 1923)

'Thorshaven' 1928

-

Christensen (1935)

'EUiott, H.F.I. Pequena' 1948 1952 Sept, Oct, Dec February 27-30 Broekhuysen & M Elliott ( 1957) acnae (1949)

1952 Sept, Oct, Dec Ripley (1954)

Gough Island Sci. Survey 1955-1956 Novl3-May13 Holdgate (1958), Swales (1965). Wilson & Swailes (1958)

'Brittania' 1957 January Edinburgh (1962)

Scheer 1960 February Voous (1961 ), Voous (1962)

La Grange 1961

-

La Grange (1961)

Fitzpatick Institute 1968 May1-19 Elliott (1969), Elliott (1970a), Elliott ( 1970b)

Richardson 1972 October Ms. (inpossessionofW.R.P. Boume)

Curtis 1973 Oct13- Ms. (in possession ofW.R.P. Bourne)

Shaughnessy & Fairall 1973 Oct 13-Nov 11 Johnstone et al. (J 976), Shaughnessy & Fairall (1976)

Richardson 1974

-

Ms. (in possessionofW.R.P. Bourne)

Curtis 1974 November12 Curtis (1977)

Voisin 1977 Oct25- Nov1 Voisin (1979a), Voisin (J979b), Voisin & Bester(in press)

FitzPatrick Institute 1978 - · Ms. (FitzPatrick Institute)

FitzPatrick Institute 1979 Oct30-Novll Bourne Ms. (FitzPatrick Institute), Brooke et al. ( 1980) FitzPatrick Institute 1979 Oct30-Nov 11 Bourne (1981). Bourne Ms. (at FitzPatrick Institute).

Bourne&Imber(1982),Brookeeta/. (1980), WiUiams

& Laycock (1981), this paper.

FitzPatrick Institute 1980 Oct 21-Nov 19 Clancey(198I), Clancey eta/. (1981)

FitzPatrick Institute 1981 Sept6-26 This paper

- - - -

*(Present address: Nature Conservation, Private Bag 13306, Windhoek, South West Africa/Namibia.)

S. Afr. J. Antarct. Res., Vol. 12, 1982 ₄₁

supplemented by observations made by members of the 1980- 1981 meteorological team stationed at Gough Island.

whereas Swales ( 1965) reported populations of I 000 and 10 000 pairs at the same localities. Whether Swaks grossly overestimated the population or there has been a major

tlcclinc is not known.

Sea birds

EudJ ptes chry.'>Otome rockbopper penguin

l'hc breeding population in 1979 was estimated to be 90 000

± 25 000 pairs ( Williams IW>Oa) compared with Swale ·s ( 1965) estimate of "two million"(') individuals). In September 19!\1 the populations in The Glen and Sophora Glen were ~00 and 800 individuals respectively ( R. Anderson pers. comm.)

First eggs were recorded on 22 September 1981. 1 he stomach~ of five chicks contained mainly crustaceans. particu- larly Tlrysanoessa spp .. and some fi~h and squid remains (Williams & Laycock 19RO).

Diomedea e:.:ul:ms wandering albatross

Sw;tlcs ( 1965) reported a population of 2 000 pairs. In 1979.

fable 2

Checklist of the birds of Gough Island.

Species

Aptenodytes paragoniws Pygoscelis papua Eudypres chrysocome Diomedea exulans Diomedea melanophris Diomedea cawa Diomedea chrysostoma Diomedea Chlororhynchos Phoebetria fusca

l'hoebetria palpebraw Macronectes halli Macronectes giganteus Fulmarus glacialoides Daption capense Pterodroma macroptera Pterodroma incerta Pterodroma lessoni Prerodroma brevirostris Pterodroma mol/is Pachyptila vilfatta Proce/laria aequinuctialis Procellaria cinerea Calonecrris diomeclea Puffin us grm>is Puffin us grLreus Puffin us assimilis Oceanites oceanicus Garrodia nereis Pelagodroma marina Fregarra tropica/grallaria Pe/ecanoides exsul Ardeacocoi Egretta alba Egretta tlmla Bubulcus ibis Anasspp.

Catharacta antarctica Stercorarius longicaudus Larus dominicanus Sterna virtata Sterna paradisaea Anous stolid us Gallinula comeri Hirundo rustica Phylloscopus troclrilus Rowettia gouglrensis

Prc 1979 observations

Br.

V V

Br.

V V Br.

June 1961 (1) Autumn 1977 (2)

V (4,7.5) V

Br.

V (6) Br.

Br.

Br.? Br.

V I Feb. 1973 (5) Br.

V Br.

Br.'?

Br.?

Br.

V 1May1968(5&7) V I'?May 1974 V 1,22 Apr-2 May 1974 V I May 1968, 1 May 1974

3 Apr-May 1975 (5) V 1 May 1968 Br.

V occasional in winter Br.

V Oct. 1977 (2) Br.

.Br.

Br.

Notes: Br.

=

Breeding species, V= visitor or vagrant

Statusandobservationsin 1979.1980,1981

Br. c. 90 000 pairs (3) Br. At least660pairs

V Upto10inTransvaaiBayl979

V I immature D.c.cautaon 30 October 1979

V Adult and immature birds seen at sea within sight ofGough island t979

Br.

V

Br. 49 nests found 1979 V 3 on 31 October 1980

V Maximum 40 in Transvaal Bayon31 October 1980 Br.

Br.

V I flewoverplateauon210ctober 1980 Br.

Br.

V I in Transvaal Bay 1979, None seen 1980, 1981 Br.

Br.

V Br.

V 2 in Transvaal Bay 1979, 9on 31 October 1980 Br.

Br.? Flying inland at night

Br.? Birds calling at night in Gonydale, 1979 Br.

Br.

V I off east coast on 30 October 1979 V I immatureon6-26September 1981 Br.

Br.

V 2on 3 November 1979 V t on3November 1979 Br.

References: (I) La Grange (1961); (2) Voisin (1979a); (3) Williams (l980a); (4) Ripley (1954); (5) Richardson (in litt. to Bourne);

(6) Verrill (1895) who lists Pterodroma lessoni but this is based on a specimen from Kerguelen and the "muttonbirds" which Comer recorded at Gough Island were almost certainly birds belonging to other Pterodroma spp.; (7) Holdgate (in litt. to Bourne).

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Ornithological observations at Gough Island in 1979, 1980 and 1981

A.J. Williams*

Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7700 and M.J. Imber Wildlife Service, Dept. of Internal Affairs,

Private Bag, Wellington, New Zealand

A bibliography of ornithological visits and a checklist of the birds of Gough island are followed by a ~ystematic account of incidental observations made on birds during expeditions to Gough Island during November 1979, October-November 1980, and September 1981. During these expeditions 33 species were observed of which six were recorded at Gough Island for the first time. The populations of Eudyptes chrysocome and Diomcdea cxulans were censused. Incidental notes include weight and mensura/ data and observations on prey consumed.

'n Bibliografie oor ornitologiese besoeke en 'n oorsiglys van voels van Gough-eiland word gevolg deur sistematiese versfag van toevallige observasies van voels tydens ek~pedisies na Gough-eiland gedurende November 1979, Oktober-November 1980, en September 1981. Tydens hierdie ekspedisies is 33 spesies waargeneem waarvan ses vir die eerste keer vir Gough- eiland aangeteken is. Populasies Eudyptes chrysocome en Diomedea exulans is gesensus. Toevallige observasies sluit in mates en gewigte en observasies met betrekking tot prooi inname.

Introduction

Gough Island (40°S, i0°W) is situated in the South Atlantic Ocean s0me 2 800 km from southern Africa and 3 200 km from South America and lies in sub-Antarctic waters about 350 km south of the subtropical convergence. Ornithologists have visited the island during some 22 expeditions and their findings have been documented in 37 publications (Table I). In all ~4 species of birds have been recorded at the island (Table 2). By ecological grouping these are: sea birds -36 species of which 17 are known to, and four may, breed and 13 are visitors or vagrants; waterside birds - five species. all vagrants; and landbirds (sensu faro)- four species of which two breed and two are vagrants.

This paper reports ornithological observations made during brief expeditions to the island from 30 October to 12 November 1979.21 October to 19 November 1980, and 6 to 26 September 1981 by members and guests of the Percy Fitz- Patrick Institute of African Ornithology. These accounts are

Table I

Ornithological visits to Gough Island.

Name of e":pedition/

observer Year of visit Period ashore Publications

'Telegraph' Een 1869 31 May La yard (1869), Brooke (1979)

Corner 1888-1889 Aug22-Jan23 Allen (1892), Verrill (1895)

'Scotia' 1904 April22 Clarke (1905), Clarke (1913), Bruce ( 1905)

'Quest' 1922 May27-June1 Lowe (1923), Wilkins (1922), Wilkins ( 1923)

'Thorshaven' 1928

-

Christensen (1935)

'EUiott, H.F.I. Pequena' 1948 1952 Sept, Oct, Dec February 27-30 Broekhuysen & M Elliott ( 1957) acnae (1949)

1952 Sept, Oct, Dec Ripley (1954)

Gough Island Sci. Survey 1955-1956 Novl3-May13 Holdgate (1958), Swales (1965). Wilson & Swailes (1958)

'Brittania' 1957 January Edinburgh (1962)

Scheer 1960 February Voous (1961 ), Voous (1962)

La Grange 1961

-

La Grange (1961)

Fitzpatick Institute 1968 May1-19 Elliott (1969), Elliott (1970a), Elliott ( 1970b)

Richardson 1972 October Ms. (inpossessionofW.R.P. Boume)

Curtis 1973 Oct13- Ms. (in possession ofW.R.P. Bourne)

Shaughnessy & Fairall 1973 Oct 13-Nov 11 Johnstone et al. (J 976), Shaughnessy & Fairall (1976)

Richardson 1974

-

Ms. (in possessionofW.R.P. Bourne)

Curtis 1974 November12 Curtis (1977)

Voisin 1977 Oct25- Nov1 Voisin (1979a), Voisin (J979b), Voisin & Bester(in press)

FitzPatrick Institute 1978 - · Ms. (FitzPatrick Institute)

FitzPatrick Institute 1979 Oct30-Novll Bourne Ms. (FitzPatrick Institute), Brooke et al. ( 1980) FitzPatrick Institute 1979 Oct30-Nov 11 Bourne (1981). Bourne Ms. (at FitzPatrick Institute).

Bourne&Imber(1982),Brookeeta/. (1980), WiUiams

& Laycock (1981), this paper.

FitzPatrick Institute 1980 Oct 21-Nov 19 Clancey(198I), Clancey eta/. (1981)

FitzPatrick Institute 1981 Sept6-26 This paper

- - - -

*(Present address: Nature Conservation, Private Bag 13306, Windhoek, South West Africa/Namibia.)

supplemented by observations made by members of the 1980- 1981 meteorological team stationed at Gough Island.

whereas Swales ( 1965) reported populations of I 000 and 10 000 pairs at the same localities. Whether Swaks grossly overestimated the population or there has been a major

tlcclinc is not known.

Sea birds

EudJ ptes chry.'>Otome rockbopper penguin

l'hc breeding population in 1979 was estimated to be 90 000

± 25 000 pairs ( Williams IW>Oa) compared with Swale ·s ( 1965) estimate of "two million"(') individuals). In September 19!\1 the populations in The Glen and Sophora Glen were ~00 and 800 individuals respectively ( R. Anderson pers. comm.)

First eggs were recorded on 22 September 1981. 1 he stomach~ of five chicks contained mainly crustaceans. particu- larly Tlrysanoessa spp .. and some fi~h and squid remains (Williams & Laycock 19RO).

Diomedea e:.:ul:ms wandering albatross

Sw;tlcs ( 1965) reported a population of 2 000 pairs. In 1979.

fable 2

Checklist of the birds of Gough Island.

Species

Aptenodytes paragoniws Pygoscelis papua Eudypres chrysocome Diomedea exulans Diomedea melanophris Diomedea cawa Diomedea chrysostoma Diomedea Chlororhynchos Phoebetria fusca

l'hoebetria palpebraw Macronectes halli Macronectes giganteus Fulmarus glacialoides Daption capense Pterodroma macroptera Pterodroma incerta Pterodroma lessoni Prerodroma brevirostris Pterodroma mol/is Pachyptila vilfatta Proce/laria aequinuctialis Procellaria cinerea Calonecrris diomeclea Puffin us grm>is Puffin us grLreus Puffin us assimilis Oceanites oceanicus Garrodia nereis Pelagodroma marina Fregarra tropica/grallaria Pe/ecanoides exsul Ardeacocoi Egretta alba Egretta tlmla Bubulcus ibis Anasspp.

Catharacta antarctica Stercorarius longicaudus Larus dominicanus Sterna virtata Sterna paradisaea Anous stolid us Gallinula comeri Hirundo rustica Phylloscopus troclrilus Rowettia gouglrensis

Prc 1979 observations

Br.

V V

Br.

V V Br.

June 1961 (1) Autumn 1977 (2)

V (4,7.5) V

Br.

V (6) Br.

Br.

Br.? Br.

V I Feb. 1973 (5) Br.

V Br.

Br.'?

Br.?

Br.

V 1May1968(5&7) V I'?May 1974 V 1,22 Apr-2 May 1974 V I May 1968, 1 May 1974

3 Apr-May 1975 (5) V 1 May 1968 Br.

V occasional in winter Br.

V Oct. 1977 (2) Br.

.Br.

Br.

Notes: Br.

=

Breeding species, V= visitor or vagrant

Statusandobservationsin 1979.1980,1981

Br. c. 90 000 pairs (3) Br. At least660pairs

V Upto10inTransvaaiBayl979

V I immature D.c.cautaon 30 October 1979

V Adult and immature birds seen at sea within sight ofGough island t979

Br.

V

Br. 49 nests found 1979 V 3 on 31 October 1980

V Maximum 40 in Transvaal Bayon31 October 1980 Br.

Br.

V I flewoverplateauon210ctober 1980 Br.

Br.

V I in Transvaal Bay 1979, None seen 1980, 1981 Br.

Br.

V Br.

V 2 in Transvaal Bay 1979, 9on 31 October 1980 Br.

Br.? Flying inland at night

Br.? Birds calling at night in Gonydale, 1979 Br.

Br.

V I off east coast on 30 October 1979 V I immatureon6-26September 1981 Br.

Br.

V 2on 3 November 1979 V t on3November 1979 Br.

References: (I) La Grange (1961); (2) Voisin (1979a); (3) Williams (l980a); (4) Ripley (1954); (5) Richardson (in litt. to Bourne);

(6) Verrill (1895) who lists Pterodroma lessoni but this is based on a specimen from Kerguelen and the "muttonbirds" which Comer recorded at Gough Island were almost certainly birds belonging to other Pterodroma spp.; (7) Holdgate (in litt. to Bourne).

(3)

42

792 chicks were counted in an almost complete survey during fine weather (Fig. 1). In 1980. 661 chicks were found in the same areas and in 19gJ 431 chicks wen! counted in a smaller area in poor weather. The number of chicks in Gonydale was 63 in 1979, 53 in 1980 (R. Cassidy pers. comm.). and 66 in 1981. In I 981 chicks survived to September at 59 of an original 80 nests at which eggs were laid, a breeding success (to September) of74 per cent (I. Martin pers comm. ). In the three years I 979-1981 ten adults and 195 chicks were ringed.

Food samples were obtained from 17 individuals. Some of these were cast pellets but most were forced regurgitations from chicks. These samples contained 570 squid beaks and the remains of four fish. About 60 per cent of the squid belonged to the Histioteurhidae.

Diomedea chlororhynchos yellownosed albatross

In 1981 the first egg was recorded on 21 September. Chicks hatched at 11 of 13 studied nests (85% hatching success) and fledged at 7 nests (64% fledging success) in 1980-1981, an overall breeding success of 54 per cent (1. Martin pers.

comm.). The mean weight of 32 unsexed adults was 2 242

±231 g. Mensura! data (mm) were: culmen 114,4 ±4, I (n 26);

tarsus 83,2 ±3,0 (n 26); and wing 472,8 ±87.4 (n 11). Two pellets contained the remains of five squid.

Phoebetria fusca sooty albatross

In 1981 the first egg was recorded on 22 September. In the 1981 winter this species left Gough Island later but returned earlier than D. chlororhynchos (1. Martin pers. comm.).

The mean weight of 15 unsexed adults was 2 454 ±301 g (1980-3 010). Mensura! data (mm) were: culmen 111,0 ±4,6 (102,3-120,3 n 15); tarsus 84,1 ±2,1 (81,0-87,9, n 15); and wing 518,4 ±13,0 (503-533, n 5). Four pellets contained primarily squid beaks. Squid of the family Cranchiidae formed 60 per cent of all beaks but only Onychoteuthid squid would have been important by weight.

Macronectes halli northern giant petrel

This species was seen only offshore in attendance at the expedition ship. In 1979, 5 of 18 and, in 1981, 9 of 32 Macronectes petrels swimming behind the ship were halli.

1l1acronectus giganteus southern giant petrel

1 wo breeding colonies were discovered in November 1979.

All adults at these colonies had green ungues typical of M. [ iganieus. We therefore follow Voisin and Bester (in press) in treating the birds breeding at Gough Island as M. giganteus.

One colony comprised five nests (one empty. four with chicks) and was situated in an unnamed interior valley between Battle Bay and Sea Hen Crags (Fig. 1). The second colony contained 44 nests (5 empty, 3 with eggs, 36 with chicks) and was situated on the slopes below West Rowett at what may be the locality reported by Swales (1965). Both colonies were situated close

S. Afr. T. Antarkt. Nav., Deel 12, 1982

A single white-phase individual was seen on 5 and 20 September 1981.

Pterodroma macroptera grcatwinged petrel

A chick killed by skuas on 1 I November 1979 was within a few weeks of fledging.

Pterodroma incerta Atlantic petrel

Five chicks found in burrows during November l979were at various stages of feathering but all were less developed than the P. macroptera chick thus suggesting that this species breeds 4-6 weeks later than P. macroptera. An infertile egg measured 70.0 x 52,5 mm. A freshly dead adult female weighed -165 g. Food samples (regurgitations or stomach contents) were obtained from 13 adults and chicks. The diet by proportionate weight was: cephalopods 70 per cent; fish 17 per cent; and crustaceans 13 per cent. The cephalopods were mainly Histioteuthidae and Cranchiidae with Gonatidae of secondary importance. The fish were mainly Mystophidae and Scomberesox saunts. The crustaceans were mysids (Gnathopausia) and amphipods, mainly a large mesopelagic lysianassid.

Pterodroma mol/is softplumaged petrel

Many birds were displaying but no eggs or young were found on 9 November 1979. Two stomachs contained the beaks of 9 squid belonging to the Histioteuthidac. Cranchiidae and Mastigoteuthidae.

Procellaria aequinoctialis whitechinned petrel

A single bird flew near the ship at anchor off Gough Island on 30 October 1979. None was seen in 1981. If this species breeds at Gough Island, as Swales' (1965) report suggests, then this conspicuous species which returns to land well before dusk should have been evident in both September and November.

Procellaria cinerea grey petrel

A female which died after colliding with the meteorological station on 19 May 1979 (and kept frozen) had a distended cloaca indicating recent egglaying. Numerous corpses of chicks were found in November 1979 but no live chicks, suggesting that fledging occurred in October or earlier.

A single stomach contained the remains of nine squid, mainly Cranchiidae and Histioteuthidae, and a single isopod.

Pufflnus gravis greater sbearwater

In 1981, 10 were seen offshore on 10 September, numbers rose to c. 60 000 on 18 September, and many birds returned to their burrows by 26 September. A period of burrow cleaning and courtship follows this initial retum and then in late October there is a prelaying exodus. In 1979 few were seen before 5 November, a raft of c. 5 000 formed offshore on 6 November. the first birds returned to their burrows on 7th, and by 12th 7 of 12 burrows examined contained fresh eggs. One stomach sample contained the remains of22 squid of which 70 per cent were juvenile Ommastrephidae, probably Todarodes sp .. and the remainder were mainly Histioteuthidae.

to the upper limit of the treefern Blechnum palmiforme and most nests were placed against the bole of a treefern. Both colonies contained chicks still being guarded and some that were unguarded. Three addled eggs measured 94,4 X 61.7, 99.8 x 64,1 and 111,9 x 65,0 mm. Sixteen adults were caught.

Sexed on the basis of comparative culmen and tarsus lengths they were nine males and seven females. Mensura! data (mm) were: culmen length, males 95,6 ±2.3, females 81,8 ±2,3;

culmen depth, males 34,3 ±0,8, females 29.9 ±0.6; tarsus length, males 93,7 ±3,2, females 85,6 ±2.8. Four of these adults, one at the small and three at the large colony, bore rings. All had been caught feeding at seal carcasses on the east coast of Gough Island during 1977-1978.

PuffiiJUS griseus sooty shearwater

Several birds were seen among tlocks of greater shearwaters in 1979. Tn 1980 regular seawatches between 24 October and 5 November again revealed small numbers of this species among greater shearwater flocks. However, none was seen to come ashore with the greater shearwaters and all had gone by 5 November.

S. Afr. J. Antarct. Res., Vol. 12, 1982

Battle Bay

*A

'-.

"'• Sea Hen Crag

•

^\

._

... \

...

^_.- ^/

8

*

Macronectes colonies

.i. Peaks and survey points

r "'

Wandering albatross census areas

\.

..

⁾

E

• N. Rowett

\

• Rowetts \-'

I •

....

/

* / \ J\

^F

\ /

·--

43

Fig. 1. Map of Gough Island showing some topographical features, the position of colonies of Macronectes petrels and the wandering albatross survey areas. The albatross survey areas are as follows: A Sea-Hen Crags Valley; B West Point slopes; C False Peak slopes;

D Tarn Moss; E Spire-Crag to Albatross Plain; F Gonydale; G Tafelkop.

Pufflnus assimilis little shearwater

Three eggs were found in 1979 one of which pipped on 9-10 November indicating that this species is a summer breeder at Gough Island. A single stomach contained only the beaks of very small squid, juveniles mainly of Ommastrephidae.

Garrodia nereis grey backed storm petrel

In 1979 only two were seen. A female containing a soft- shelled egg collided with the meteorological station on 28 October 1980. In 1981 single birds were caught at the station on 18. 19 and 22 September.

Pelecanoides uri11atrix subantarctic diving petrel

A bird which landed on the relief ship Agulhas in September 1981 laid an egg measuring 35,5 x 28,2 mm and weighing 16 g.

The stomach of a single bird contained only crustaceans -13 euphausiids and an hyperid amphipod.

Catllaracta BIJtarctica subantarctic skua

In 1981 the first eggs were found on 18 September. ln November 1979 most nests on low ground near the meteor-

ological station had large chicks - although a presumably replacement egg was laid there on 9 November- whereas at about 50 per cent of the nests on the central plateau the birds were still incubating. Mensura! data (mm) from 18 eggs at Gough Island were: length 71,3 ±3,4 (66,3-76,7), breadth 50,6 ±1,3 (48,1-52,8). These data confirm that the eggs ofthe race hamiltoni, which breeds at Gough Island and other rela- tively warm sub-Antarctic islands, are similar in size to those of nominate antarctica from the Falkland Islands (14 eggs aver- age·d 69,8 x 51,9, Murphy 1936) but are substantially smaller than those of Ca. lonnbergi (136 eggs from Marion Island averaged 76.4 x 52,7, Williams 1980 b). Of 373 petrel carcasses at skua middens Pterodroma mol/is formed 44 per cent and Pachyptila vittata 34 per cent.

Larus dominicanus kelp gull

In 1981 a single dark immature bird, a juvenile or second year bird judging by its appearance, was at the beach in Trans- vaal Cove throughout the period 6 to 26 September (Griffiths 1981). Investigations of the intertidal invertebrates at Gough Island during 1981 revealed a marked absence of patelloid

~

(4)

42

792 chicks were counted in an almost complete survey during fine weather (Fig. 1). In 1980. 661 chicks were found in the same areas and in 19gJ 431 chicks wen! counted in a smaller area in poor weather. The number of chicks in Gonydale was 63 in 1979, 53 in 1980 (R. Cassidy pers. comm.). and 66 in 1981. In I 981 chicks survived to September at 59 of an original 80 nests at which eggs were laid, a breeding success (to September) of74 per cent (I. Martin pers comm. ). In the three years I 979-1981 ten adults and 195 chicks were ringed.

Food samples were obtained from 17 individuals. Some of these were cast pellets but most were forced regurgitations from chicks. These samples contained 570 squid beaks and the remains of four fish. About 60 per cent of the squid belonged to the Histioteurhidae.

Diomedea chlororhynchos yellownosed albatross

In 1981 the first egg was recorded on 21 September. Chicks hatched at 11 of 13 studied nests (85% hatching success) and fledged at 7 nests (64% fledging success) in 1980-1981, an overall breeding success of 54 per cent (1. Martin pers.

comm.). The mean weight of 32 unsexed adults was 2 242

±231 g. Mensura! data (mm) were: culmen 114,4 ±4, I (n 26);

tarsus 83,2 ±3,0 (n 26); and wing 472,8 ±87.4 (n 11). Two pellets contained the remains of five squid.

Phoebetria fusca sooty albatross

In 1981 the first egg was recorded on 22 September. In the 1981 winter this species left Gough Island later but returned earlier than D. chlororhynchos (1. Martin pers. comm.).

The mean weight of 15 unsexed adults was 2 454 ±301 g (1980-3 010). Mensura! data (mm) were: culmen 111,0 ±4,6 (102,3-120,3 n 15); tarsus 84,1 ±2,1 (81,0-87,9, n 15); and wing 518,4 ±13,0 (503-533, n 5). Four pellets contained primarily squid beaks. Squid of the family Cranchiidae formed 60 per cent of all beaks but only Onychoteuthid squid would have been important by weight.

Macronectes halli northern giant petrel

This species was seen only offshore in attendance at the expedition ship. In 1979, 5 of 18 and, in 1981, 9 of 32 Macronectes petrels swimming behind the ship were halli.

1l1acronectus giganteus southern giant petrel

1 wo breeding colonies were discovered in November 1979.

All adults at these colonies had green ungues typical of M. [ iganieus. We therefore follow Voisin and Bester (in press) in treating the birds breeding at Gough Island as M. giganteus.

One colony comprised five nests (one empty. four with chicks) and was situated in an unnamed interior valley between Battle Bay and Sea Hen Crags (Fig. 1). The second colony contained 44 nests (5 empty, 3 with eggs, 36 with chicks) and was situated on the slopes below West Rowett at what may be the locality reported by Swales (1965). Both colonies were situated close

A single white-phase individual was seen on 5 and 20 September 1981.

Pterodroma macroptera grcatwinged petrel

A chick killed by skuas on 1 I November 1979 was within a few weeks of fledging.

Pterodroma incerta Atlantic petrel

Five chicks found in burrows during November l979were at various stages of feathering but all were less developed than the P. macroptera chick thus suggesting that this species breeds 4-6 weeks later than P. macroptera. An infertile egg measured 70.0 x 52,5 mm. A freshly dead adult female weighed -165 g. Food samples (regurgitations or stomach contents) were obtained from 13 adults and chicks. The diet by proportionate weight was: cephalopods 70 per cent; fish 17 per cent; and crustaceans 13 per cent. The cephalopods were mainly Histioteuthidae and Cranchiidae with Gonatidae of secondary importance. The fish were mainly Mystophidae and Scomberesox saunts. The crustaceans were mysids (Gnathopausia) and amphipods, mainly a large mesopelagic lysianassid.

Pterodroma mol/is softplumaged petrel

Many birds were displaying but no eggs or young were found on 9 November 1979. Two stomachs contained the beaks of 9 squid belonging to the Histioteuthidac. Cranchiidae and Mastigoteuthidae.

Procellaria aequinoctialis whitechinned petrel

A single bird flew near the ship at anchor off Gough Island on 30 October 1979. None was seen in 1981. If this species breeds at Gough Island, as Swales' (1965) report suggests, then this conspicuous species which returns to land well before dusk should have been evident in both September and November.

Procellaria cinerea grey petrel

A female which died after colliding with the meteorological station on 19 May 1979 (and kept frozen) had a distended cloaca indicating recent egglaying. Numerous corpses of chicks were found in November 1979 but no live chicks, suggesting that fledging occurred in October or earlier.

A single stomach contained the remains of nine squid, mainly Cranchiidae and Histioteuthidae, and a single isopod.

Pufflnus gravis greater sbearwater

In 1981, 10 were seen offshore on 10 September, numbers rose to c. 60 000 on 18 September, and many birds returned to their burrows by 26 September. A period of burrow cleaning and courtship follows this initial retum and then in late October there is a prelaying exodus. In 1979 few were seen before 5 November, a raft of c. 5 000 formed offshore on 6 November. the first birds returned to their burrows on 7th, and by 12th 7 of 12 burrows examined contained fresh eggs. One stomach sample contained the remains of22 squid of which 70 per cent were juvenile Ommastrephidae, probably Todarodes sp .. and the remainder were mainly Histioteuthidae.

to the upper limit of the treefern Blechnum palmiforme and most nests were placed against the bole of a treefern. Both colonies contained chicks still being guarded and some that were unguarded. Three addled eggs measured 94,4 X 61.7, 99.8 x 64,1 and 111,9 x 65,0 mm. Sixteen adults were caught.

Sexed on the basis of comparative culmen and tarsus lengths they were nine males and seven females. Mensura! data (mm) were: culmen length, males 95,6 ±2.3, females 81,8 ±2,3;

culmen depth, males 34,3 ±0,8, females 29.9 ±0.6; tarsus length, males 93,7 ±3,2, females 85,6 ±2.8. Four of these adults, one at the small and three at the large colony, bore rings. All had been caught feeding at seal carcasses on the east coast of Gough Island during 1977-1978.

PuffiiJUS griseus sooty shearwater

Several birds were seen among tlocks of greater shearwaters in 1979. Tn 1980 regular seawatches between 24 October and 5 November again revealed small numbers of this species among greater shearwater flocks. However, none was seen to come ashore with the greater shearwaters and all had gone by 5 November.

Battle Bay

*A

'-.

"'• Sea Hen Crag

•

^\

._

... \

...

^_.- ^/

8

*

Macronectes colonies

.i. Peaks and survey points

r "'

Wandering albatross census areas

\.

..

⁾

E

• N. Rowett

\

• Rowetts \-'

I •

....

/

* / \ J\

^F

\ /

·--

43

Fig. 1. Map of Gough Island showing some topographical features, the position of colonies of Macronectes petrels and the wandering albatross survey areas. The albatross survey areas are as follows: A Sea-Hen Crags Valley; B West Point slopes; C False Peak slopes;

D Tarn Moss; E Spire-Crag to Albatross Plain; F Gonydale; G Tafelkop.

Pufflnus assimilis little shearwater

Three eggs were found in 1979 one of which pipped on 9-10 November indicating that this species is a summer breeder at Gough Island. A single stomach contained only the beaks of very small squid, juveniles mainly of Ommastrephidae.

Garrodia nereis grey backed storm petrel

In 1979 only two were seen. A female containing a soft- shelled egg collided with the meteorological station on 28 October 1980. In 1981 single birds were caught at the station on 18. 19 and 22 September.

Pelecanoides uri11atrix subantarctic diving petrel

A bird which landed on the relief ship Agulhas in September 1981 laid an egg measuring 35,5 x 28,2 mm and weighing 16 g.

The stomach of a single bird contained only crustaceans -13 euphausiids and an hyperid amphipod.

Catllaracta BIJtarctica subantarctic skua

In 1981 the first eggs were found on 18 September. ln November 1979 most nests on low ground near the meteor-

ological station had large chicks - although a presumably replacement egg was laid there on 9 November- whereas at about 50 per cent of the nests on the central plateau the birds were still incubating. Mensura! data (mm) from 18 eggs at Gough Island were: length 71,3 ±3,4 (66,3-76,7), breadth 50,6 ±1,3 (48,1-52,8). These data confirm that the eggs ofthe race hamiltoni, which breeds at Gough Island and other rela- tively warm sub-Antarctic islands, are similar in size to those of nominate antarctica from the Falkland Islands (14 eggs aver- age·d 69,8 x 51,9, Murphy 1936) but are substantially smaller than those of Ca. lonnbergi (136 eggs from Marion Island averaged 76.4 x 52,7, Williams 1980 b). Of 373 petrel carcasses at skua middens Pterodroma mol/is formed 44 per cent and Pachyptila vittata 34 per cent.

Larus dominicanus kelp gull

In 1981 a single dark immature bird, a juvenile or second year bird judging by its appearance, was at the beach in Trans- vaal Cove throughout the period 6 to 26 September (Griffiths 1981). Investigations of the intertidal invertebrates at Gough Island during 1981 revealed a marked absence of patelloid

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44

limpets (Dr. C. Hay pers. comm.). Since limpets are an, if not the, most important food source for kelp gulls at other sub- Antarctic localities (Ealey 1954, Downes et al. 1959, Simpson 1976. Jehl et al. 1.979. Blankley 1981) the absence of such limpets at Gough Island may be a major factor in the failure of kelp gulls to breed there.

Anous stolid us common noddy

None were seen in September 1981 but more than a hundred were present in the vicinity of the meteorological station in 1979 and some were paired but none had laid by 12 November.

Land and waterside birds

Egretta sp

A single egret, probably E. alba, flushed in The Glen on 9 November 1981 was repeatedly attacked by skuas whilst it flew.

Gallinula comeri Gough rail

A pair with two chicks were seen near the meteorological station on 5 November 1979.

Hirundo rustica European swallow Pbylloscopus trochilus willow warbler

Two European swallows and a single willow warbler were seen in the vicinity of the meteorological station on 3 November 1979 by 1. C. Sinclair. These are the first old world landbirds to be recorded at Gough Island.

Rowettia goughensis Gough bunting

In November 1981 chicks at most lowland nests had fledged.

Nine occupied nests were found in 1979, seven each with two chicks of various sizes, the younger ones with dark down, one from which a single chick "exploded", and one in Gonydale with two eggs. The two nests in the open upland area were sunk in scrapes beneath overhanging tufts of Cyperus sedge.

Two nests in lower gorges were six to ten feet above ground- one in a cleft in a bare rock face the other on a ledge in a fern- covered rock wall. Nests at low altitude were in clumps of fern Elaphoglossum sp. (2 nests), in a treefem Blechnum palniforme (1 nest), in the roots of a fallen Phylica tree (1), ana in tussock grass Spartina sp. (1). The eggs were blue with sparse grey-brown blotches at the larger end.

Acknowledgements

We are grateful to the South African Department of Trans- port who provided Jogistical support on the advice of the South African Scientific Committee for Antarctic Research. The following are thanked for making their observations available to the authors: R. Anderson, A. Berruti, R. Cassidy, S. Fugler, A. Griffiths, C. Hay, I. Martin, J. ^Nielsen,^J.C.

Sinclair and P. Steyn. We thank W.R.P. Boume for the use of his observations and for critical comment on an earlier draft.

References

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BLANKLEY, W.O. 1981. Marine foods of Kelp Gulls. Lesser Sheathbills and Imperial Cormorants at Marion Island (Sub- Antarctic). Cormoram9: 77-84.

BOURNE. W.R.P. 1981. Fur Seals return to Gough Island. Oryx 16:

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BOURNE, W.R.P. & 1MBER, M.J. 1982. Plastic pellets collected by

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BROOKE, R.K., SINCLAIR, J.C. & BERRUTI, A. 1980.

Geographical variation in Diomedea chlororhynchos (Aves:

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Exped. Rpts., Ser. B, 1: l-135.

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ELLIOIT, H.F.I. 1957. A contribution to the ornithology of the Tristan da Cunha group. Ibis 99: 545-586.

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ELL! OTI, C. C. H. 1970 b. Ecological considerations and the possible significance of weight variations in the chicks of the Great Shear- water on Gough Island. Ostrich, supplement 8: 385-396.

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LA GRANGE, J.J. 1961. News from the island stations. Newsletter, Weather Bureau, Pretoria 147: 92.

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45

WILKJNS. G.H. 1923. Report on the birds collected during the voyage ol the Quesr (Shackk:ton-Rowctt Expedition) to the South Atlimtic. Ibis. Scr. I!. 5: -17-1--195.

WILLIAMS. A.J. 1980 a. Hockltopper Penguins Eudypre.1 chry.wmme at Gnugh Island. Bull. Br. Om. Club lOO: 20il-212.

WILLIAMS. A.J. 19Rtl b. Aspcctsofthe breeding biology of the Sub- antarcticSkua at :'vlarion Island. Ostnch 51: 160-!67.

WILLIAMS. A.J. & LA YCOCK. P.A. 19~1. Euphausiids in the diet of some Sub-Antarctic Eudypres p<:nguins. S. A fr. J. A111arc1. Res.

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Mag. 6-1: 43--15.

Bird ringing at Marion and Prince Edward islands, 1977-1982

C.R. Brown Percy FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch , 7700 and T.B. Oatley South African Bir d Ringing Unit, University of Cape Town, Rondebosch, 7700

Bird ringing activities at Marion and Prince Edward islands are summarised for the period June 1977- May 1982. A total of 2 423 birds of 21 species was ringed during this period and 57 recoveries or recaptures were recorded at Marion Island. Only five birds have been recovered or recapwred elsewhere during the review period. Twenty-three foreign-ringed birds have been recorded on Marion Island and there is increasing evidence for movemem of birds. including king penguins, between the Prince Edward islands and the Crozet islands. it is noted that ringing of birds at Marion Island is chiefly of value in studies of their breeding behaviour but yields few data on post-breeding dispersal.

Voelberingings aktiwiteite op Marion- en Prins Edward- eilande, tl./SSen Junie 1977-Mei 1982, word opgesom. 'n Totaal van 2 423 voels van 21 soorte was gedurende die tydperk gering en 57 terugkrygings of herowerings was op Marion-eiland aangeteken. Net vy( voifls was gedurende die onderhawige tydvak op ander lokaliteite teruggekry of herower. Drie-en- twintig uitheemse-geringde voi:!ls was op die eiland aangeteken en daar is meer en meer bewys van beweging van voels, die koningpikkewyn ingesluit, tussen die Prins Edward-eilande en die Crozet-eilande. Dit word gemerk dat beringing van voels op Marion·eiland word van waarde, vera/ in studies van hul/e broeigedrag, maar /ewer min inligting op hulle na-broeise verspreiding.

Introduction

This paper covers bird-ringing activities at Marion ( 46°52'S, 37°51 'E) and Prince Edward (46°38'S, 37°57'E) islands for the period June 1977 to May 1982 inclusive and supplements previous reports by Bcrruti et al. (1975) and Burger and Morant (1977). The nomenclature followed is that of Clancey ( 1980). There have been two name changes since publication of the last report. The lesser broadbillcd or Salvin's prion, Pachyptila salvini, is here referred to as the mediumbilled prion to distinguish it from the broadbilled prion, P. vittata.

the great skua, Stercorarius skua longbergi, is now called the subantarctic skua. Catlzaracta antarctica.

Methods

Altogether 2 423 birds of 21 species were ringed during the period under consideration. Four species, the yellownosed albatross, Diomedea chlororhynchos, grcyheaded albatross, D. chrysos10ma, imperial cormorant, Phalacrocorax atriceps. and king penguin, Aptenodytes patagonicus, were ringed for the first time. This brings the total number of birds ringed at Marion and Prince Edward islands since October 1951 to 6 048 individuals of 26 species (Table 1). Of these, 57

have been recovered or recaptured at Marion Island since June 1977 (Table 1) and

a

further five have been recovered or

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