VOL. 11 (5) MARCH 1986 153

AUSTRALIAN BIRD WATCHER 1986, II, 153-166

Birds of Cherry , Altona, - Annotated Comments on Species and Seasonal Movements

By J.S. HUMPHREYS, 9 Pakenham Street, Blackburn, Victoria 3130

Summary Over a period of three years (July 1982 to July 1985 inclusive), 56 approximately three­ weekly surveys were made of the avifauna of Cherry Lake in metropolitan (coastal Victoria). A total of 112 species (11 introduced) was recorded, 28 (25%) of them breeding. There was little seasonal variation in the average number of species recorded, but the composition of the avifauna changed seasonally: palaearctic waders and other migrants predominated in spring-summer; waterbirds and seabirds predominated in summer (possibly partly drought-related during the study period); winter visitors included altitudinal migrants and nectar-feeding lorikeets and honeyeaters when eucalypts were flowering. It is concluded that Cherry Lake is an important metropolitan bird habitat, particularly for waterbirds and grassland birds.

Introduction The objective of this article is twofold- fir:st, to provide an annotated list of species sighted at Cherry Lake, Altona, Victoria, and second, to outline their seasonal patterns for the period July 1982-July 1985. These data will hopefully add to the already extensive, yet incomplete, information relating to the region's avifauna.

Location Cherry Lake (37° 52'S, 144° 50'E, 3.0 m elevation), is situated within metropolitan Melbourne, and located approximately 15 km by road from the Melbourne G. P.O. (see Figure 1). Cherry Lake is a freshwater lake located on the basalt plains to the west of Melbourne, and the local area is consequently very flat. Its situation, only I km from the of Bay, has a significant effect on the number and types of birds found there. Port Phillip Bay and its surrounds are both nationally and internationally significant for the rich variety of birdlife supported by their coastal and habitats (see Lane et al. 1984). Although Cherry Lake is located within the boundaries of the Local Government Authority of Altona, the Melbourne and Metropolitan Board of Works (MMBW) has jurisdiction over it, while the Altona City Council assumes responsibility for the upkeep of the adjacent recreation and resetve areas. As shown in Figure 2, the study area comprises Cherry Lake, the Cherry Creek inlet and the adjacent recreation areas.

Climate Figure 3 shows the monthly rainfall totals as recorded at the meteorological station at Altona Council Offices adjacent to Cherry Lake. The nearest climatic station for which temperature data are available is located some 7 km west of Altona at Laverton, and Table 1 provides the mean daily AUSTRALIAN 154 HUMPHREYS BIRD WATCHER

N 0 2 3 4 5 Kilometres

"0 0"' Westgate 0: '""·~

WILLIAMSTOWN

SALTWORKS PORT PHILLIP BAY

Figure 1. Location of Cherry Lake, Altona, Victoria.

N J .: :::~:::~~::•11 StoMn

t -- Fence Une

·oo 200 300 Met•es

Figure 2. Cherry Lake study area. VOL. II (5) MARCH 1986 Birds of Cherry Lake, Altona, Victoria 155

maximum and minimum temperatures recorded there. Temperatures range from a mean daily maximum of25.8°C in January to a mean daily minimum of 4.8°C in July (see Table 1). Meteorological records for the period 1967-1983 indicate that Altona experiences a mean annual rainfall of 605 mm distributed evenly over most months. As shown in Figure 2, the period of this study included the drought years of 1982-83 and 1984-85. The below average rainfall experienced at Altona for both these summers is apparent. In contrast, 1983 was a year of above average rainfall, and the extremely wet conditions experienced at Cherry Lake in the second half of 1983 most likely account for the absence of several species normally seen in the area during these months. In short, observations suggest that both numbers and types of species occurring at Cherry Lake have exhibited a close relationship to the general pattern of rainfall over the study period.

mm 120

100

80

60

40 Means 1967-1983 20

1982 1983 1984 1985

Figure 3. Monthly rainfall, Altona, January 1982-July 1985.

Vegetation Unlike Melbourne's undulating eastern suburbs, the flat basalt plains of its western suburbs are sparsely vegetated and consist essentially of grasslands. In this context, the immediate surrounds of Cherry Lake provide an excellent wetland area, combining grassy paddocks, native trees and shrubs, lakeside reed beds and areas of wetland weeds and grasses. The predominant dryland shrub vegetation of the lake surrounds comprises large areas of Tangled Lignum Muehlenbeckia cunninghamii and Thorny Plagianth Selanothamnus squamatus, and these species form favoured habitats for grassbirds, fairy­ wrens, chats and finches. The wetland areas of rushes and sedgeland (Carex spp., Gahnia spp., Juncus spp., Phragmites spp. and Typha spp.) are homes for V> Table 1 -0\

Maximum (upper) and minimum (lower) temperatures for Laverton (37° 52'S, 144° 45'E, elevation 6 m) July 1982-June 1985

Year Mean daily temperature ('C) J F M A M J J A s 0 N D Year 1982 13.1 17.8 16.7 19.8 25.2 23.6 20.7 1.9 4.9 4.5 7.1 9.9 12.0 8.9 1983 24.4 28.7 24.0 18.2 16.7 13.3 12.8 15.2 16.3 17.4 20.4 24.0 19.3 11.2 14.9 14.4 9.1 8.3 4.6 4.7 6.9 7.0 8.8 10.0 12.4 9.4 1984 23.9 26.0 22.5 19.5 18.0 15.1 12.9 15.5 15.3 19.6 22.4 22.6 19.4 :r: 12.6 13.0 10.7 8.5 5.4 4.7 3.6 6.1 5.9 7.6 10.2 10.7 8.3 c:::: ~ 1985 24.3 24.7 25.6 21.8 17.9 :r:'"0 12.4 12.6 14.5 11.0 6.5 :::0 1943-1984 av. 25.8 25.8 23.6 20.0 16.6 14.0 13.5 14.8 16.9 19.0 21.2 23.7 ~ 13.6 14.2 12.5 9.9 7.7 5.6 4.8 5.4 6.5 8.2 9.8 11.9 C/l

Table 2

Variation in number of species by season

Season No. trips Average no. species Standard deviation Spring 16 39.1 6.63 Summer 15 46.0 6.61 Autumn 13 46.2 6.05 Winter 12 44.8 7.32 VOL. 11 (5) MARCH 1986 Birds of Cherry Lake, Altona, Victoria 157 significant numbers of ibis, herons, spoonbills, egrets, waders, and other waterbirds. Even the areas heavily infested by weeds (especially Dumex crispus) contain concentrations of sandpipers and snipe in summer months. The existing trees have mostly been planted in the area by the Altona City Council, and comprise Melaleuca (especially M ericifolia, M nesophila and M styphelioides) and Eucalyptus species (especially E. leucoxylon, E. globulus, E. kitsoniana and E. cladocalyx). These trees provide habitats for parrots, honeyeaters, cuckoo-shrikes, magpies and introduced species.

Land use Cherry Lake is located in an area of heavy industry, being in the midst of several large petrochemical complexes. Cherry Lake is now predominantly a recreational area, combining sports facilities with walking and running circuits, and fishing in the lake. Picnic facilities are available, and the adjacent area is used for various fairs and events throughout the year. Residential land use on the west and south sides ensures that human usage of the area is heavy. During the period of this study, it has been apparent that this factor has contributed significantly to damage to the area, largely through illegal off-road vehicular intrusion, pollution through rubbish dumping and weed invasion, excessive trampling of lake edges, and deliberately lit fires. These problems exacerbate the loss of resulting from MMBW and Council drainage and reclamation activities, and the loss of native vegetation that has occurred due to horses and rabbits grazing in the area.

Methods The selection of Cherry Lake for this study originated from an entry in a Bird Observers Club publication that listed the area as a bird-watching region near Melbourne. On arrival in Melbourne in 1982, a reconnaissance of the area was made. I decided to make regular trips to the area despite its location some 40 km from my eastern suburbs home. Visits were made every month at approximately three-week intervals, although these were more frequent in spring and autumn in order to ascertain the approximate times of arrival and departure of migrant waders. A total of 56 trips was made from July 1982 to July 1985, eleven of which were in the company of fellow bird-watchers. A standard circuit of2-3 hours was traversed on each occasion, with observations commencing at dawn. The circuit commenced at the swampy areas and small lagoons of the south­ western corner of the lake (where waterbirds and some waders are usually prevalent but disappear or become less conspicuous once disturbed), continued around Cherry Lake, and concluded with a survey of the surrounding dryland environs. The trips were normally made on a Sunday morning, except when the weather was too bad for bird-watching or during the weeks of arrival and departure of waders, or when out-of-state visitors were interested to see the area. Because of the size of the study area itself (particularly Cherry Lake), and the many instances of human disturbance putting birds to flight, it was not possible to conduct an exact count of the numbers of all species and so only estimates were possible in some instances. AUSTRALIAN 158 HUMPHREYS BIRD WATCHER

Results The following list of species observed at Cherry Lake is not exhaustive. The adoption of early morning as observation time clearly precludes the sighting of some species known to occur in the general area, but which are normally sighted at other times of the day- for example, the Southern BoobookNinox novaeseelandiae and White-throated Needletail Hirundapus caudacutus. Nonetheless, the following data might provide a basis for a more intensive 'scientific' survey of the area conducted at different times of the day and over certain periods of the year.

Systematic list The numbers included in brackets for each species indicate the number of visits (total: 56) on which that particular species was sighted. Introduced species are indicated (I) in the annotated list. Dates of arrival and departure of waders are included in the discussion section.

Great Crested Grebe Podiceps cristatus Single adult bird seen in late August 1983 and March 1984, and immature in March 1985. (3) Hoary-headed Grebe Poliocephalus po/iocepha/us Commonly seen throughout year, often in quite large numbers. Absent in spring-summer 1983. Breeding. (43) Australasian Grebe Tachybaptus novaehollandiae Commonly seen throughout year, often in groups of 6-8 birds. Winter-dominant and largely absent in spring. Breeding. (30) Australian Pelican Pelecanus conspicil/atus Seen on almost every visit, sometimes in flocks of up to 20 or more birds. Normally 4-8 birds. (53) Great Cormorant Phalacrocorax carbo Seen regularly throughout year, though never more than a few birds at a time. (43) Pied Cormorant Phalacrocorax varius Single bird seen only on a few occasions, even though sizeable numbers can be regularly seen on the nearby coast of Port Phillip Bay at the Cheetham Saltworks. (5) Little Black Cormorant Phalacrocorax sulcirostris Seen regularly throughout year, at times in flocks of up to 100 birds. Normally fewer. Summer-dominant, and absent late winter-early spring. (35) Little Pied Cormorant Phalacrocorax melanoleucos Seen regularly though never in large numbers - up to 9 birds. Less commonly seen in spring. (41) Pacific Heron Ardea pacifica Single bird sighted once in winter 1985. (I) White-faced Heron Ardea novaehollandiae Single bird or pair regularly sighted all year round, although fewest sightings in spring. (39) Great Egret Egretta alba Sighted throughout year, although more common in drier seasons and absent in spring, summer and autumn in 1983-84. (20) Intermediate Egret Egretta intermedia Flock of 13 sighted in April 1984, and a single bird in September 1984. (2) Australasian Bittern Botaurus poiciloptilus Single bird sighted at dawn in May 1984. Possible sightings in June and July of same year not claimed due to inadequate early morning light (I) Glossy Ibis Plegadis falcinel/us Flock of 9 birds seen in summer 1985. (I) VOL. 11 (5) MARCH 1986 Birds of Cherry Lake, Altona, Victoria 159

Sacred Ibis Threskiornis aethiopica Regularly seen each year in flocks of up to 20 birds, although commonly fewer. Dominant in autumn, and largely absent in spring and summer. (41) Straw-necked Ibis Threskiornis spinicollis Visitor in winter 1984, summer 1984-85 and winter 1985. (6) Royal Spoonbill Platalea regia Seen regularly, sometimes in groups of up to 15 birds, though commonly fewer. Summer and autumn dominance. Breeding plumage in spring 1983. (32) Yellow-billed Spoonbill Platalea jlavipes Seen on most visits, except during prolonged absence July 1983- April 1984. Up to 20 birds, though commonly 2-8. (31) Black Swan Cygnus atratus Permanent resident regularly seen in numbers exceeding 200 birds. (53) Australian Shelduck Tadorna tadornoides Seen regularly, though summer-dominant. Commonly 10-12 birds but on occasions up to 30 birds. (30) Pacific Black Duck Anas superciliosa Permanent resident, often in large numbers of 50-100 birds. Breeding. (54) Mallard Anas platyrhynchos (I) Suspect permanent resident, but not always seen easily. Only 2-4 birds. Breeding. (38) Grey Teal Anas gibberi.frons Commonly seen throughout year, often in large numbers of 50-100. Absent summer and autumn 1983. (41) Chestnut Teal Anas castanea Seen irregularly until winter 1984, and thereafter Qn almost every visit Small numbers up to 6. Breeding. (25) Australasian Shoveler Anas rhynchotis Usually small numbers of 6-8, although in excess of 20 birds on a few occasions. Dominant in the two driest summers. Absent July 1983 - June 1984. (25) Pink-eared Duck Ma/acorhynchus membranaceus Irregular and uncommon visitor. Usually single bird, although in flocks of more than 100 birds in autumn 1985. (10) Hardhead Aythya australis Uncommon visitor, only seen regularly since winter 1984. Up to 8 birds seen, but usually only 2-3 birds. (12) Maned Duck Chenonetta jubata Uncommon visitor since 1984. Male seen on 4 occasions, but female only twice. (4) Musk Duck Biziura lobata Seen only since summer 1984-85, although often seen in Yarra River near Williamstown. (3) Black-shouldered Kite £/anus notatus Occasional visitor seen hunting over lake and surrounds. (5) Marsh Harrier Circus aeruginosus Occasional visitor seen hunting over lake area, and more commonly over the adjacent . (4) Black Falcon Falco subniger Rare bird seen only once in summer 1983-84. (I) Australian Hobby Falco longipennis Irregular visitor seen hunting over lake edges. (5) Australian Kestrel Falco cenchroides Occasional visitor seen since winter 1984. (5) Stubble Quail Cotumix novaezelandiae Single birds sighted in dry summer months 1982-83 and 1984-85. (3) Brown Quail Coturnix australis Pair sighted in dry summer months 1982-83 and 1984-85. (4) AUSTRALIAN 160 HUMPHREYS BIRD WATCHER

Buff-banded Rail Rallus philippensis Single bird sighted only since winter 1984. Possibly resident of surrounding reed area. (7) Lewin's Rail Ral/us pectoralis Single bird sighted in January 1984. (l) Baillon's Crake Porzana pusilla Seen every year, especially when water levels begin to fall. Up to 10 birds, though more commonly in pairs or singly. Suspect permanent resident. (19) Australian Crake Porzana jluminea One or two birds seen in 1982-83 drought-year summer, and flushed once in winter 1985. (6) Spotless Crake Porzana tabuensis Single bird seen most easily in dry summer months. (4) Black-tailed Native-hen Gallinula ventralis Several birds seen in spring 1982 and 1984-85 skulking around edges of reeds. (7) Dusky Moorhen Gallinula tenebrosa Permanent breeding resident easily seen. (54) Purple Swamphen Porphyria porphyria Permanent breeding resident. Numerous and easily seen. (56) Eurasian Coot Fu/ica atra Permanent breeding resident. Easily seen, often in very large numbers. (56) Masked Lapwing Vane/Ius miles · Permanent breeding resident of grassy areas. Easily seen, sometimes in groups of 20-50 birds. (51) Banded Lapwing Vanellus tricolor Up to 5 birds seen in grassy areas in spring months. (6)

Curlew Sandpiper Calidrisfe"uginea (left) and Red-necked Stint Calidris ruficollis (right), Werribee, Victoria, October 1981 Plate 40 Photo: Peter Klapste VOL. II (5) MARCH 1986 Birds of Cherry Lake, Altona, Victoria 161

Red-capped Plover Charadrius ruficapillus, Werribee, Victoria Plate 41 Photo: Peter Klapste

Red-kneed Dotterel Erythrogonys cinctus Seen in quite large numbers, 20-50 in spring and summer of 1982 and 1984-85. Mostly absent in winter and wetter times. (26) · Red-capped Plover Charadrius ruficapillus Single sighting of 2 males and 1 female in summer 1983-84, although quite common at nearby Cheetham Saltworks. (1) Black-fronted Plover Charadrius melanops Dominant in winter and spring along main drainage inlet. (9) Black-winged Stilt Himantopus himantopus Summer vi-sitor absent in winter. Often numerous with 50-100 birds. Breeding. (36) Red-necked Avocet Recurvirostra novaehollandiae Visitor in summer 1982-83 and 1984-85, easily seen in numbers up to 50 birds. Entirely absent in wetter year. (24) Wood Sandpiper Tringa glareola Single bird sighted in early autumn 1985. (1) Greenshank Tringa nebularia Summer migrant seen 1982-83 and 1984-85. (6) Latham's Snipe Gallinago hardwickii Spring and summer migrant. Not easily seen unless flushed, and numbers never exceed 8-1 0 and possibly dwindling. (32) Sharp-tailed Sandpiper Calidris acuminata Summer migrant often in numbers of 100 or more. Easily seen at lake edges. (23) Pectoral Sandpiper Calidris melanotos Migrant Single bird sighted among Sharp-tailed Sandpipers in sumrrier 1982-83. (2) · Red-necked Stint Calidris ruficollis Summer migrant 1982-83 and 1984-85 associating with Curlew Sandpipers. On occasions up to 20 birds. (6) Curlew Sandpiper Calidris ferruginea Summer migrant 1982-83 and 1984-85. Seen in numbers up to 100, and with early breeding plumage just prior to departure for northern hemisphere. (12) Silver Gull Larus novaehollandiae Permanent breeding resident in the area. Seen in large numbers. (56) AUSTRALIAN 162 HUMPHREYS BIRD WATCHER

Black Swan Cygnus atratus, Royal Botanical Gardens, Melbourne, Victoria Plate 42 Photo: Peter Klapste

Pacific Gull Larus pacijicus A few birds seen in winter months. Adult and immature. (15) Whiskered Tern Chlidonias hybrida Several birds commonly seen in spring and early summer months. Breeding and non­ breeding plumage. (19) Gull-billed Tern Gelochelidon nilotica Two birds sighted in spring 1985. (I) Caspian Tern Hydroprogne caspia One or two birds seen in each spring. (3) Common Tern Sterna hirundo Single bird seen in spring 1985. (2) Feral Pigeon Columba Iivia (I) Permanent resident in local area, frequently seen in flocks overhead. (48) Spotted Turtle-Dove Streptopelia chinensis (I) Common resident of local area. (39) Galah Cacatua roseicapilla Flock seen in late winter-early spring 1984, and winter 1985. (3) Sulphur-crested Cockatoo Cacatua galerita Two birds seen flying overhead in spring 1983. (I) Purple-crowned Lorikeet Glossopsitta porphyrocephala Up to 50 birds seen feeding on flowering eucalypts in the area in autumn-winter months 1983 and 1985. (6) Blue-winged Parrot Neophema chrysostoma Single birds seen feeding in winter 1984. (I) Pallid Cuckoo Cuculus pallidus Several birds seen in spring 1982. (2) Horsfield's Bronze-Cuckoo Chrysococcyx basalis Commonly seen in spring months. (14) Singing Bushlark Mirafra javanica Two sightings in spring and summer 1983. (2) VOL. 11 (5) MARCH 1986 Birds of Cherry Lake, Altona, Victoria 163

Skylark Alauda arvensis (I) Permanent breeding resident. Numerous throughout grassy areas. (55) Welcome Swallow Hirundo neoxena Permanent resident commonly seen in large numbers, although numbers present vary noticeably according to season. (56) Fairy Martin Cecropis ariel Several birds usually seen in spring months. (12) Richard's Pipit Anthus novaeseelandiae Visitor in late spring and summer months to grassy paddocks. (12) Black-faced Cuckoo-shrike Coracina novaeho/landiae Sightings of one or two birds each year. (4) White-winged Triller Lalage sueurii Passage migrant seen in spring months. (3) Blackbird Turdus merula (I) Permanent breeding resident. (51) Pink Robin Petroica rodinogaster Female bird seen in winter 1983. (I) Flame Robin Petroica phoenicea Often seen in autumn and winter months. (14) Scarlet Robin Petroica multicolor One female seen in autumn 1984. (I) Grey Fantail Rhipidura fuliginosa A few birds seen in spring months. (6) Willie Wagtail Rhipidura leucophrys Permanent resident of area, commonly seen. (43) Clamorous Reed-Warbler Acrocephalus stentoreus Spring and summer migrant commonly seen in cumbungi Typha domingensis. Breeding. (28) Little Grassbird Megalurus gramineus Suspect a permanent resident, although difficult to see at times and more commonly heard. (34) Golden-headed Cisticola Cisticola exilis Permanent breeding resident. Numerous and easily seen. (49) Brown Songlark Cinclorhamphus crura/is Seen in grassy area in summer 1982-1983 and spring 1983. (2) Superb Fairy-wren Malurus cyaneus Permanent breeding resident. Numerous. (56) Calamanthus Sericornis fuliginosus Permanent resident of area. (50) Yellow-rumped Thornbill Acanthiza chrysorrhoa Visitor in summer 1983-84 and 1984-85. (3) Red Wattlebird Anthochaera carunculata Permanent resident of area. (37) Spiny-cheeked Honeyeater Acanthagenys rufogularis Single bird seen feeding on blossom in winter 1984. (I) Singing Honeyeater Lichenostomus virescens Three birds seen feeding on eucalypt blossom in spring 1983. (I) White-plumed Honeyeater Lichenostomus penicillatus Permanent breeding resident of area. (54) Crescent Honeyeater Phylidonyris pyrrhoptera Single bird seen feeding on blossom in winter 1983. (I) New Holland Honeyeater Phy lidonyris novaehol/andiae Several birds seen in winter and spring 1984, and winter 1985. (6) Tawny-crowned Honeyeater Phylidonyris melanops Single bird seen feeding on blossom in winter 1983. (1) AUSTRALIAN 164 HUMPHREYS BIRD WATCHER

White-fronted Chat Ephthianura albifrons Permanent breeding resident Numerous. (56) Silvereye Zosterops latera/is Spring and summer visitor in small parties. (7) European Goldfinch Carduelis carduelis (I) Seen in all months, although summer-dominant. Breeding. (23) European Greenfinch Carduelis chloris (I) Regularly seen, although summer-dominant Breeding. (20) House Sparrow Passer domesticus (I) Permanent breeding resident Numerous. (54) Tree Sparrow Passer montanus (I) Permanent breeding resident of area. Numerous. (44) Common Starling Sturnus vulgaris (I) Permanent breeding resident. Numerous. (55) Common Mynah Acridotheres tristis (I) Permanent breeding resident Numerous. (55) Australian Magpie-lark Grallina cyanoleuca Permanent breeding resident. (54) Australian Magpie Gymnorhina tibicen Permanent breeding resident. (34) Australian Raven Corvus coronoides Permanent resident of area. (30) Little Raven Corvus mellori Permanent resident of area. (30)

Discussion One hundred and twelve species were positively identified, of which 11 are introduced species. Twenty-five species (22.3%) were seen on more than 75% of the visits, and forty-four species (39.2%) were seen on more than 50% of the visits. Sixteen species were seen on only one occasion. On the basis of sighting recently fledged or downy young twenty-eight (25.0%) were classified as breeding. (It is acknowledged that in some cases the actual breeding may have occurred elsewhere). The maximum number of species seen on any one trip was 60 (late summer, 1985) and the minimum number was 29 (spring, 1983). (Results of the reconnaissance trip have been excluded). The average number of species seen was 43, with relatively little variation in the number of species from season to season (see Table 2). However, one significant aspect of the avifauna of this area is the seasonal variation apparent in the type of species. In this study, some notable patterns are evident from the data that were collected. (Obviously these comments must be regarded as preliminary to some extent since single or few sightings of some species require more regular visits to the area or an extended study period in order to confirm a definite seasonal calendar). Probably the most significant variation is the seasonal influx of several northern hemisphere waders which remain resident over the summer months around the Port Phillip Bay littoral areas. Cherry Lake records of these waders, with dates of earliest and latest sightings, are as follows: Wood Sandpiper (11 March - only sighting), Latham's Snipe (2 September- 12 March), Sharp-tailed Sandpiper (2 September-17 March), Pectoral Sandpiper (19 September-19 December), Red-necked Stint (19 December-17 March), and Curlew Sandpiper (19 September-17 March). VOL. 11 (5) MARCH 1986 Birds of Cherry Lake, Altona, Victoria 165

The springtime arrival of waders is complemented by the arrival or passage through the area of other northern migrants. These include the Pallid Cuckoo, Horsfield's Bronze-Cuckoo, Fairy Martin, White-winged Triller, Grey Fantail and Clamorous Reed-Warbler. As spring merges into summer, Whiskered Terns are regularly seen, while Gull-billed, Caspian and Common Terns are occasionally sighted. Summer-dominant species normally include the Little Black Cormorant, a variety of ducks (Australian Shelduck, Australasian Shoveler and Pink-eared Duck) and crakes (Baillon's, Australian, Spotless), the Red-necked Avocet, Greenshank, Yellow-rumped Thornhill, European Goldfinch and European Greenfinch. In addition, abnormally high numbers of such species as crakes, Black-tailed Native-hens, Banded Lapwings, and certain raptors in the early months of summer in 1982-83 and 1984-85 may well be associated with the occurrence of major drought at these times, particularly in inland Victoria. Even though the water level at Cherry Lake fell dramatically, and the surrounds were quite dry during these periods, some water remained throughout, even during the peak of summer. Moreover, proximity of Cherry Lake to the coastal areas of the Werribee Sanctuary and Cheetham Saltworks ensures sufficient suitable habitat within a reasonable distance. During the winter months various species, not normally seen at other times of the year, regularly visit the area. These include the Pacific Gull, Blue­ winged Parrot and robins (Pink, Flame and Scarlet). The regular sighting of other species in winter seems to parallel closely the eucalypt-flowering calendar. Notable amongst this group are the Purple-crowned Lorikeet and several honeyeaters (Spiny-cheeked, Singing, Crescent, New Holland and Tawny-crowned). During the period of the study, it has been evident that both the local and statewide pattern of rainfall has been a critical factor in not only maintaining the physical environment of Cherry Lake and its surrounds, but also in determining the likely occurrence of certain bird species in the area. At times when rainfall totals were extremely low in inland areas of Victoria (as in summer 1982-83 and 1984-85), there occurred significant movement of some inland species to suitable wetter environments on the coast, such as Cherry Lake.

Conclusions In line with the findings of Lane et al. (1984), it is apparent that Cherry Lake represents a significant habitat for large numbers of a wide range of species. This is particularly true fo r waterbirds and birds which live in or depend on grass. In addition, the seasonal variation experienced over the period of a calendar year ensures that the area provides an exciting year-long venue for both amateur and professional ornithologists. Unfortunately, the rather fragile wetland environment is being rapidly despoiled, particularly as the result of thoughtless human interference. For example, over the study period the number of snipe visiting the area has declined noticeably, and the reduction of suitable habitat through irresponsible human activity would seem to be a contributing factor. It is hoped that increasing information about the numbers, species and seasonal variation found in this area will promote a greater realisation of the need to ensure the maintenance and preservation of this wetland area as a matter of urgency. VELLENGA: AUSTRALIAN 166 Immature Bowerbirds, bower-building behaviour BIRD WATCHER

Acknowledgements I wish to acknowledge the assistance of Graham Barwell, Peter Valentine, Anthea and Jim Whitelaw in confirming and/or identifying both bird and vegetation species, and for comments on an earlier draft of this paper.

Reference Lane, B.A, Schulz, M. & Wood, KL. (1984), Birds ofPort Phillip Bay, Coastal Unit Technical Report No. 1, Ministry for Planning and Environment, Government Printer, Melbourne•.

Short Notes-

Bower-building Behaviour of Immature Satin Bowerbirds Ptilonorhynchus violaceus

The importance of the bower in the life history of the Satin Bowerbird Ptilonorhynchus violaceus is well known: it is the focal point of the reproductive cycle, whereby mature males attract and mate with females (e.g. Schodde 1976). My husband Sidney Vellenga and I studied the biology and behaviour of Satin Bowerbirds between 1960 and 1971 at Leura, New South Wales (Vellenga 1970; 1980a, b; Vellenga & Vellenga 1985). In our study of the beh aviour of males at their bowers we recorded that adult (blue) males dominated immature (green) males, and that the latter appeared to learn the art of bower building from the adult males (Vellenga 1970). Here we provtde additional notes on the rudimentary bowers built by immature males. Observations on learning behaviour commenced in September 1967 when immature males built two rudimentary display areas, one with a rough bower, in our garden; this was repeated in the following year. The study area and methods have been described previously (Vellenga 1980b) . We colour-banded some hundreds of Satin Bowerbirds, and observations on known individuals were conducted in our suburban garden which was within the territory of a dominant adult male. The general shape and structure of bowers and size of sticks used by immature birds have been previously recorded (Vellenga 1970). Whereas the adult (blue) male used long, thin twigs of teatree Leptospermum sp., two- and three-year-old birds brought thick twigs of unsuitable shape and tried unsuccessfully to place them. Bowers built by immatures were not as well constructed as those of mature males, and not as well decorated. Only the older green birds placed sticks upright for an avenue wall, and even four-year­ old birds were not very proficient builders. Needles from pines Pinus radiata, though not usually found at bowers, were placed on a platform built and tended by immature birds in August to October 1967. This was decorated each morning with fresh flowers and other objects. Young birds up to three years old brought display objects of inappropri ate colours to their bowers. Although the colours were usually blue. fawn a nd yellow, they were always paler than shades used by mature birds. However. young birds did not bring completely wrong colours such as