Corella4 {4) SEABIRDISLANDS No.96

Shellback Island, Wilsons Promontoryo

Location:38"58'S.. 146"14'E.t the most north- erly island on the western side of Wilsons SHELLBACKISLAND, VICTORIA Promontory;2.2 km to nearestmainland.

Status: Part of National Park; accessis controlled by the National Parks Service,Victoria.

Description: 37 ha:, a steep-sidedgranite island about1.0 km long,0.6 km wideand of maximum height 109 m. The dominant vegetationis Poa poilormis tussocksand a few scatteredbushes including Melaleuca ericilolia, Correa alba and one plant of the genusCesuorina. The island has much exposedsmooth granite, and some areasof overlyingtussock grass are beingeroded. "?r-= Landing: Onto the rocky coastline of northem crnE rn4 ^ L-/ry FEE sideof island. Eilt

Ornithological History: Apart from passing re- mShon.tailed Shea.water 1!, ference to Cape Barren Geese formerly the a island was unknown ornithologically.We visited the island for about 45 minutesin torrential rain on 13 December1978. S. G. Lane andH. Battam m (pers. comm.) spent about two hours ashoreon 10 November1979 while B. Robertsonand P. i*.eh nlpr Thomas made a further visit of 2.5 hours on 20 December1979. ing birds. The island's population may possibly be severalhundred pairs. Breeding Seabirdsand Status Pachyptilq turtur Fairy Prion - Two dead Eudyptula minor Little Penguin - Their num- birds were found in December 1978. In No- bers were not countedbut we iound manv breed- vember 1979, Lane and Battam found a num- November,1980 M. P. Haftls ef a/.. Shellback lsland 99

Other SeabirdsRecorded

Leutocarbo luscescens Black-faced Shag Larus noraehollandiae Silver Gull

Banding "runners" C. novaehollandiae- 3 (10 Nov. 79). L. pacificus..._ "runners";(20 ' 2l Dec. 79)l Shellback Island. (looking west)- one was found dead on nearby Norman Beach on 3 Feb. 80.

Bibliography ber of cavities and remains of an egg on the 1. Ports and Harbours (1959), Sailing Directions Vic- north-easternend (Lane pers. comm.). toria including . Dept. of Public Works, Melbourne. 6th edition:433. 'The Pufrinus tenubostrls Short-tailed Shearwater- 2. Dorward, D. F. (1967), statusof Cape Barren On the slopingsides (estimated area 24.5 ha), Goose Cereopsis novae-hollandiae', Bull. int. Comm. Bird Presert'. 10:56-71. where there is much exposed granite, we de- termined mean burrow density in twenty-one 20 m2 quadratsas 0.21 burrbws/m:; on the flatter top (12.3 ha), the mean burrow density in 30 quadrats was 0.48/m:. The total numbei of burrows on the island was estimatedas lO9 5OO(95% confidenceinterval 87400-131 600).

Pelecanoides urinetrix Common Diving-Petrel - We found one dead bird and a few remains were.found by Lane and Battam. The species possiblybreeds on the island.

Cereopsisnoyaehollandiqe Cape Barren Goose - Possiblybreeding. We recorded15-18 birds includingflying young.On 10 November1979, some 50 were counted including three groups of non-flyingyoung (Lane pers. comm.)-.

Haematopusluliginosus Sooty Oystercatcher- A nest with two eggswas found on 10 Novem- ber 1979 (Lane pers. comm.).

Larus pacificusPacific Gull - About 100 pairs were presentin December1978, most ol thich were probably breeding.In November 1979, almost th€ same number was presentand 3l nests were counted. Most nests contained eggs but some were still being constructed (Line Date compiled:January 1980. pers. comm.) . M. P. Harris*, D. M. Deeryont and R. S. Brownl. 4Institule ol Terrestrial Ecology, Banchory Research Factors Affecting Status Station, Hilt of Rrulhens, Banclrcr)), Kintardineshire, AB3 4RY, U.K. Erosion of Poa areaswas causing slight loss i Artllur R))lah Institute lor Enyironmental Research, Fisheries and l4rildlile Di)ision, 123 Brown Street, of shearwaterbreeding habitat. Heidelbery,Yic.,3084.