The first recorded breeding of kelp gulls Larus dominicanus vetula on Robben Island, Western Cape, South Africa, took place in 2000, when five nests were recorded. In 2001, there were 15 nests and 29 fledglings. The initiation of breeding by kelp gulls on Robben Island is likely a response to the reduction of disturbance since the Robben Island Museum took control of the island. Afr. J. mar. Sci. 25: 391–39

CALF, K M

COOPER, J

UNDERHILL, L G

English

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Kriel et al. (1980), in their review of breeding seabirdson Robben Island, Western Cape, South Africa, between1949 and 1980, specifically noted that kelp gullsLarus dominicanus vetula had not been recordedbreeding on the island over this period. Brooke(1983) deduced from early records that, althoughkelp gulls were present on the island in the 17th century,there was no proof that they bred there. Crawfordand Dyer (2000) described the status of the specieson Robben Island as a “common nonbreeding resident”.Kelp gulls are invariably present at Robben Island;during seven surveys of the birds along the shorelineof the island, made between 1977 and 2001, the mediancount was 120 birds (range 39–336; Underhill et al.2001). Kelp gulls have bred at virtually all the otheroffshore islands of South Africa and Namibia, and atmany sites along the coastline; by 1997, a total of 79breeding localities had been recorded (Crawford etal. 1982, Crawford 1997d). The first nests of the kelp gull on Robben Islandwere found by JC on 30 November 2000. Four nestswere recorded in the quarry near the north-easterncorner of the island; three were empty and one con-tained three newly hatched young. One nest wasfound with three eggs on the western shoreline. Nofurther monitoring of these nests was undertaken. In 2001, the first kelp gull nest was found byKMC on 26 October, on a shell beach 100 m fromthe north-eastern quarry. It contained three eggs. By15 November there were an additional 14 nests, allinside the quarry (three with three eggs, 10 with twoand one with one). Two chicks from the first nest hadfledged by 2 January 2002. The last chick had fledgedby 15 February. The 15 nests containing 33 eggs pro-duced 29 fledglings.Kelp gulls scavenge at rubbish tips and take offaldiscarded by fishing trawlers (Crawford 1997d). Bothsources of food are available to kelp gulls breedingon Robben Island. The rubbish tips in the GreaterCape Town area are already exploited by the smallerHartlaub’s gull L. hartlaubii when it breeds on the is-land (LGU pers. obs.), and many fishing trawlerspass within a few kilometres of the island. Foodshortages are therefore an unlikely explanation of thelack of breeding by kelp gulls on Robben Island until2000.Crawford et al. (1982) noted that, at 33 of the 53kelp gull colonies known at the time, the gulls werein association with colonies of African penguinsSpheniscus demersus, cormorants or Cape gannetsMorus capensis. Although there were large coloniesof Cape cormorants Phalacrocorax capensis on RobbenIsland in the 17th century (Brooke 1983), there havebeen relatively small colonies of them on RobbenIsland since 1949, the start of the period reviewed byKriel et al. (1980). African penguins bred in large num-bers on Robben Island in the 17th century, but ceased tobreed before 1800 (Brooke 1983). African penguinsre-commenced breeding in 1984, and by 2000 thecolony had grown to be the third largest of thespecies (Crawford et al. 2000). Kelp gulls take penguineggs on Robben Island (pers. obs.). However, the peakof the penguin breeding season falls in midwinter,whereas kelp gulls breed in early to mid summer. Ittherefore seems unlikely that the penguin colonycould have played a major role in the initiation ofkelp gull breeding.Crawford et al. (1982) suggested that the reasonwhy kelp gulls had not bred on Robben Island wasthat “considerable human activity renders it unsuit-able for breeding.” Disturbance levels have decreasedsince the island was taken over by the Robben IslandAfr. J. mar. Sci. 25: 391–3932003391FIRST BREEDING RECORDS OF KELP GULLS LARUS DOMINICANUS VETULAAT ROBBEN ISLAND, WESTERN CAPE, SOUTH AFRICAK. M. CALF*, J. COOPER* and L. G. UNDERHILL*The first recorded breeding of kelp gulls Larus dominicanus vetula on Robben Island, Western Cape, SouthAfrica, took place in 2000, when five nests were recorded. In 2001, there were 15 nests and 29 fledglings. Theinitiation of breeding by kelp gulls on Robben Island is likely a response to the reduction of disturbance sincethe Robben Island Museum took control of the island.Key words: First breeding, Larus dominicanus, Robben Island, South Africa*Avian Demography Unit, University of Cape Town, Rondebosch 7701, South Africa. E-mail: kathy@adu.uct.ac.zaManuscript received June 2002; accepted January 2003Museum in 1996. Fewer people are now resident onthe island than throughout the 19th and 20th cen-turies; in the prison era (1958–1996), a large staff andtheir families lived on the island, and in 1920, whileit was a leper hospital, there were 2 000 people livingon the island (Fish 1924, de Villiers 1971, Smith1997). For many of the prison staff, angling and theassociated collection of bait formed a major recre-ational activity (LGU pers. obs.). The operation ofrunning a prison of necessity involved having staffcontinuously on duty; a by-product of this was thatsome staff were always off-duty. As a result, therewere often people present on the coastline throughoutthe day, weekdays included. The reduction in distur-bance is likely to be the key factor that has resultedin the initiation of breeding by kelp gulls on RobbenIsland.It seems likely that numbers of breeding kelp gullson Robben Island will increase rapidly. Trends ingull numbers, as well as the impact of their predationon other seabird species, should be carefully moni-tored, using current levels as a baseline. Kelp gulls areknown predators of the eggs and small young of fiveRed Data Book species which breed on Robben Island:African penguin, bank cormorant Phalacrocorax neg-lectus, Cape cormorant, crowned cormorant P. coro-natus and African black oystercatcher Haematopusmoquini (Crawford 1997a, b, c, Crawford and Whit-tington 1997, Martin 1997, Barnes 2000, BirdLifeInternational 2000, Calf and Underhill 2002). It was onaccount of the presence of precisely these five speciesthat Robben Island was designated an Important BirdArea (Barnes 1998). In addition, in some years theisland supports the largest breeding colonies of two taxaendemic to southern Africa: Hartlaub’s gull and swifttern Sterna bergii bergii. Although there is currently noneed to implement control measures for kelp gulls onRobben Island, this is an option that might soon needto be considered, noting the problems associatedwith increases in numbers of the same species offNew Zealand and Australia (Fordham 1967, Coulsonand Coulson 1998).ACKNOWLEDGEMENTSWe acknowledge support from the National ResearchFoundation, Pretoria, the University of Cape TownResearch Committee, the Earthwatch Institute, theDarwin Initiative of the United Kingdom Government,and the Skye Foundation. We especially acknowledgelogistical support from the Robben Island Museumand from Marine & Coastal Management (MCM),Department of Environmental Affairs and Tourism.Dr R. J. M. Crawford (MCM) commented on an earlierdraft.LITERATURE CITEDBARNES, K. N. (Ed.) 1998 — The Important Bird Areas of SouthernAfrica. Johannesburg; BirdLife South Africa: 394 pp.BARNES, K. N. (Ed.) 2000 — The Eskom Red Data Book ofBirds of South Africa, Lesotho and Swaziland. Johannesburg;BirdLife South Africa: 169 pp.BIRDLIFE INTERNATIONAL 2000 — Threatened Birds of theWorld. Barcelona and Cambridge; Lynx Editions andBirdLife International: 852 pp.BROOKE, R. K. 1983 — On the 17th century avifauna of RobbenIsland, South Africa. Cormorant 11: 15–20.CALF, K. M. and L. G. UNDERHILL 2002 — Productivity ofAfrican black oystercatchers Haematopus moquini onRobben Island in the 2001/02 breeding season. Wader StudyGroup Bull. 99: 45–49.COULSON, R. and G. COULSON 1998 — Population changeamong Pacific, kelp and silver gulls using natural and artifi-cial feeding sites in south-eastern Tasmania. Wildl. Res. 25:183–198.CRAWFORD, R. J. M. 1997a — Cape cormorant Phalacrocoraxcapensis. In The Atlas of Southern African Birds. Harrison,J. A., Allan, D. G., Underhill, L. G., Herremans, M., Tree,A. J., Parker, V. and C. J. Brown (Eds). Johannesburg;BirdLife South Africa: 32–33.CRAWFORD, R. J. M. 1997b — Bank cormorant Phalacrocoraxneglectus. In The Atlas of Southern African Birds. Harrison,J. A., Allan, D. G., Underhill, L. G., Herremans, M., Tree,A. J., Parker, V. and C. J. Brown (Eds). Johannesburg; BirdLifeSouth Africa: 34–35.CRAWFORD, R. J. M. 1997c — Crowned cormorant Phalacrocoraxcoronatus. In The Atlas of Southern African Birds. Harrison,J. A., Allan, D. G., Underhill, L. G., Herremans, M., Tree,A. J., Parker, V. and C. J. Brown (Eds). Johannesburg;BirdLife South Africa: 38–39.CRAWFORD, R. J. M. 1997d — Kelp gull Larus dominicanus. InThe Atlas of Southern African Birds. Harrison, J. A., Allan,D. G., Underhill, L. G., Herremans, M., Tree, A. J., Parker,V. and C. J. Brown (Eds). Johannesburg; BirdLife SouthAfrica: 462–463.CRAWFORD, R. J. M., COOPER, J. and P. A. SHELTON 1982— Distribution, population size, breeding and conservationof the kelp gull in southern Africa. Ostrich 53: 164–177.CRAWFORD, R. J. M., DAVIS, S. A., HARDING, R. T., JACKSON,L. F., LESHORO, T. M., MEYER, M. A., RANDALL, R. M.,UNDERHILL, L. G., UPFOLD, L., VAN DALSEN, A. P.,VAN DER MERWE, E., WHITTINGTON, P. A., WIL-LIAMS, A. J. and A. C. WOLFAARDT 2000 — Initialimpact of the Treasure oil spill on seabirds off westernSouth Africa. S. Afr. J. mar. Sci. 22: 157–176. CRAWFORD, R. J. M. and B. M. DYER 2000 — Wildlife ofRobben Island. Bright Continent Guide 1. Cape Town; AvianDemography Unit, University of Cape Town: 28 pp.CRAWFORD, R. J. M. and P. A. WHITTINGTON 1997 — Jackasspenguin Spheniscus demersus. In The Atlas of SouthernAfrican Birds. Harrison, J. A., Allan, D. G., Underhill, L. G.,Herremans, M., Tree, A. J., Parker, V. and C. J. Brown(Eds). Johannesburg; BirdLife South Africa: 462–463.DE VILLIERS, S. A. 1971 — Robben Island: Out of Reach, Out of392 African Journal of Marine Science 25 2003Mind. Cape Town; Struik: xv + 169 pp.FISH, J. W. 1924 — Robben Island: an Account of Thirty-fourYear’s Gospel Work Amongst Lepers of South Africa. Kil-marnock; John Ritchie: 210 pp.FORDHAM, R. A. 1967 — History and status of the Dominicangull in Wellington. Notornis 14: 144–153.KRIEL, F., CRAWFORD, R. J. M. and P. A. SHELTON 1980 —Seabirds breeding at Robben Island between 1949 and 1980.Cormorant 8(2): 87–96.MARTIN, A. P. 1997 — African black oystercatcher Haematopusmoquini. In The Atlas of Southern African Birds. Harrison,J. A., Allan, D. G., Underhill, L. G., Herremans, M., Tree,A. J., Parker, V. and C. J. Brown (Eds). Johannesburg;BirdLife South Africa: 374–375.SMITH, C. 1997 — Robben Island. Cape Town; Struik: 160 pp.UNDERHILL, L. G., WHITTINGTON, P. A. and K. M. CALF2001 — Shoreline birds of Robben Island, Western Cape,South Africa. Wader Study Group Bull. 96: 37–39.Calf et al.: First Breeding of Kelp Gulls at Robben Island, S. Africa2003 393

FIRST BREEDING RECORDS OF KELP GULLS LARUS DOMINICANUS VETULA AT ROBBEN ISLAND, WESTERN CAPE, SOUTH AFRICA

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FIRST BREEDING RECORDS OF KELP GULLS LARUS DOMINICANUS VETULA AT ROBBEN ISLAND, WESTERN CAPE, SOUTH AFRICA

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