November,l980 SEABIRDISLANDS No.92

Citadel Island, Glennie Groupo

Lccation: 39"07'5.. 146"14'8.: 7.75 km south- CITADETIStAND. VI CTORIA west from Tidal River, , Victoria. Stalus:Controlled by the CommonwealthDepart- ment of Transport (Surface Transport, Vic. Region); accessrestricted.

Description: A domed granite island of about 18 ha, some675 m long by 415 m wide, rising to a flattenedsummit, 110 m abovem.s.l., where there is an automatic navigation light and a concrete helipad. The island is exposed, pri marily to west€rlies,with only some shelter be- ing provided by neighbouring to the north and McHueh Island to the east. Much of the island's suiface is bare rock, in sheets,blocks or boulders,and vegetationis re- stricted to three major communities: (a) Pod poilormis mainly on the more sheltered,eastern I Navigation Light side, (b) Disphyma austrqle, gro\tlingin sheets above the splash zone, again mostly on the I Hclip.d easternside and (c) Leptospermumlqeyigatum scrub, which ittcltded Correa alba and Albizia Fai.vPrio' lophanthat. Where soil occurs, i1 is generally N shallow, but tbe vegetationis currently more ex- tensive than that reported in 1959 by M. E. m "iz:E# n. Gillhamr,' Further botanical details are siven + PacificGull elsewherel,2,:r'5. o 1O0 2OOm The coastline is entirely rock, either massive boulders or sheetssloping or shelvinginto deep water surroundingthe island. Landing: Onto rocks, the location depending on wind and swell. The easternside is usuallv the island on 11 December1978 and about four the most accessible. hours on 13 February 1979. Lane and Battam (pers. comm.) again visited the island for a Ornithological Hislory: F. Wood Jonesdappar- short time with B. Robertson on 13 November ently visited the island but Gillhame'3seems to 1979. have been the first to discussthe avifauna. She noted breeding Little Penguins and saw Cape Bteeding Seabirdsand Status Barren Geese and Pacific Gulls. In November 1978, H. Battam and S. G. Lane found nests Eudypnla minor LiItle Penguin- This species of Pacific Gulls and Fairy Prions on the eastern was reportedto be numerousin 1959'but we side in the limited area coveredbv them durins found only 30 nests and a further 15 burrows their brief visit.aWe sDentabout one hour oi occupiedby moulting birds. Th€sewere scattered 90 F. l. Notman & R. S. Brown: Citadel lsland Corella 4 {4)

' CitadeL Island from the air (looking south- . Another aerial yiev, (looking north-east). west).

Faclors Alfecting Statr$ around the lower slooes. in Poa and under rocks. The scarcity ot soil of adequate depth for As this species also nests well under overhangs burrowing undoubtedly restricts the number of or in deep crevices,our count must be minimal. breeding shearwaters and possibly other species. Rabbits Oryctolagus cuniculus, formerly recorded Pachyptila turtur Fairy Prion - Lanea recorded as depressing the island's vegetation and increas- nesting burrows, presumed to be this species, in ing erosion ! r, are presumed to ber extinct;. The November 1978 and we counted about 50 bur- Peregrine Falcon Falco peregrinus takes rows, mostly wder Carpobrotu,r,' two burrows prions and this may modify the population size. examined each contained a bird on an ess. Illegal haryesting of shearwaters is unlikely on Neither Gillham3 nor Wood mentiorie-rl Joneso this island. the species. Other Seabirds Recorded Puffinus tenuirostris Short-tailed $he31vy11s1- Gillham found no shearwaters nestins on Citadel Leucocarbolux:escens Black-facedshag Haematopus fuliglnosus Sooty Oyslercatcher Istand in I959:, nor did Laner in lhe area Larus novaehollandiae Silver GUE covered during his visit. We recorde4.the species nesting in December 1978 and February 1979; Banding 111 burrows were counted and those examined - (13 in December generally contained a bird on egg. E. minor 2 nestlings Nov. 79). Most of the burrows were concentrated within Poa towards the southern end but others were Bibliography found throughout the community. i. Gillham, M. E. (1960), 'Destruction of indigenous heath vegetation in Victorian sea-bird colonies', Aust. J. Rot. 8:277-311. Pelecanoides urinatrix Common Diving-Petrel 2. Gillham. M. E. (1961), 'Plants and seabirds of - A dead bird was found in December 1978, granite islandsin south-eastVictoria', P/oc. R..toc. and the islandmay be a breedingstation. Vict.75i45-63. 3. Gillham, M. E. (1962), 'Granite islands of south- east Victoria as a seabird habitat', Proc. R. Soc. Cereopsis novaehollandiae Cape Barren Goose l/ict.75:45-63. 'A - In November 1979, Lane (pers. comm.) saw 4. Lane, S. G. (1979), visit to the islands of five birds on the island and found a recently- Wilsons Promontory, Victoria', Corc a 3:29-30. 5. Norman, F. I. and R. S. Brown (1979), 'A note on used nest built over an old Pacific Gull's nest. the vegetation of Citadel Island, Wilsons Promon- saw a pair of geese in December 1978, Victoria', yictorian Nat. 96:137-142. We tory, 'The and a non-flying young (which was flying in 6. Wood Jones, F. (1937), diving petrel of the February 1979). Bass Straits', Victorian Nat. 54.51-55. 1980. Larus pacificus Pacific Gull - Lanea reported Date compiled:24 January an old nest of this speciesnear the disusedderrick F. I. Norman and R. S. Brcwn, Arthur R))lah Inttllule platform in November 1978 and two nests, each lor Environmental Research, Fisheries and llildtile with an egg, in November 1979. Dirision, 123 Brcwn Street, Heidelberg, Vic., 3084.