AUSTRALIAN 260 BIRD WATCHER Records of Freckled Duck in Victoria from December 1980 to July 1981 and of the number shot on opening day of the 1981 duck season By A. H. CORRICK* Introduction Little information has been published on the biology or abundance of Freckled Duck Stictonetta naevosa; however, it appears to be one of Australia's least abundant waterfowl (e.g. Frith 1965, 1967, Cowling 1978). There are few breeding records from Victoria (Frith 1967, Cooper 1974, Lowe & Lowe 1974, Cowling 1978) so that the small numbers usually present in northern Victoria each year must originate from breeding areas in other States. In some years they become more abundant in Victoria (e.g. 1957, 1961 and 1970 Lowe & Lowe 1974; 1979- 80 Corrick 1980). The causes of such increases are unknown but could arise through dispersal of birds from inland sites following either wet years which have enabled the population to increase by more successful and widespread breeding or very dry years which force birds away from their normal habitat as it dries. Although protected throughout Australia small numbers are shot during most duck shooting seasons in south­ eastern Australia and greater numbers when influxes occur (Lowe & Lowe 1974, Braithwaite & Norman 1974, 1976, 1977 and 1981, Corrick 1980). In a previous paper (Corrick 1980) I reported increased numbers of Freckled Duck in parts of western Victoria up to November 1980 and suggested that the large numbers shot at sites elsewhere indicated that the increase in numbers had occurred throughout Victoria and south­ east South Australia. There were insufficient reports available either to estimate the State population or the significance of the numbers shot. In this paper I report further records of Freckled Duck, from December 1980 until July 1981 inclusive, which enable an assessment of both the State population and the number shot on the opening day (7 March) of the 1981 duck shooting season. Methods Records of Freckled Duck were obtained from the following five sources: (a) my own observations on wetlands between Geelong and Mount Emu Creek (22-23 December, 23-27 February, 11-12 and 23-29 March); in the Kerang district over opening weekend (7-8 March), and Lakes H ind­ marsh, Albacutya and Buloke (24-26 January). (b) the South Australian Branch of the Field and Game Association * Arthur Rylah Institute for Environmental Research, Fisheries and Wildlife Division, Ministry for Conservation, 123 Brown Street, Heidelberg, Victoria 3084. VOL. 9 (8) DECEMBER 1982 Freckled Duck in Victoria 261 (F&GA) who have conducted a mail survey by including a post paid card in their journal circulated to 7000 members throughout Australia. Respondents were contacted to confirm their reports when either the number reported was greatly above other rcords or where groups of 50 or more were reported for the first time. (c) results of pre-season surveys of wetlands by Field Management staff of the Fisheries and Wildlife Division (FWD) who also provided records reported to them, mainly by shooters. These pre-season surveys included use of a low flying aircraft in the area between Warrnambool, Edenhope and Lake Corangamite on the 24 and 26 February. (d) data collated by the Royal Australasian Ornithologists Union (RAOU) for the Atlas of Australian Birds. Contributors to the RAOU Atlas were contacted to obtain the number, exact date and location of their sightings. (e) records from other bird observers I contacted. Results Details of all reports from individual wetlands are summarized in the following list which also includes reports lacking a precise location which are identified by a major town in the region. The source of all reports, other than my own, are identified and where contributors to other surveys (F&GA, FWD or RAOU) have provided additional information they have been acknowledged. The 10' grid squares from which Victorian reports came are shown in Figure 1. Table 1 compares Victorian reports with reports from other States over the same time. 141° 145° 147° 149° Figure 1: The occurrence, plotted on a 10' grid, of records of Freckled Duck in Victoria from December 1980 until July 1981 inclusive. AUSTRALIAN 262 CORRICK BIRD WATCHER Lake Albacutya: 5800 ha (about half this by March) 35°45'S 141 °59'E. I have eleven records from December 1980 until 6 March 1981 ranging from 4 to 400 (F. Noelker, Rainbow, pers. comm., R . Jaensch, pers. comm., FWD and my own) although other unrecorded sightings were also made (F. Noelker, pers. comm.). T he dense stands of drowned Acacia sp. in both the southern and northern parts of the Lake made accurate counts impossible; however, observers (FWD, and F. Noelker) estimated that 300 to 400 birds were present before 7 March. Other records are of 4 on 6 March; 60-80, 100 and 100-200 on 7 March; and 50 on 10 March and 3 on 24 April (F&GA). F. Noelker saw none on 15 March and 5 on 8 April but saw 45 on 20 July. On 7 March 52 corpses were collected by FWD staff who reported others they did not collect and F. Noelker counted a further 16, 38 and 27 corpses on 15 March and 5 and 8 April respectively. Thus 133 bodies were counted although more would have been shot. After 7 March most corpses were found on islands suggesting that foxes were removing many from the shoreline. The southern part of the lake, where many were reported shot on opening day, was not checked thoroughly. I consider that at least 200-250 were killed. A psley: 36°58'S 141 °05'E. Quite a few in the district, 1981 duck season (F&GA). Lake Bael Bael: 510 ha, 35o42'S 143 °44'E. There were 40 and 180 on 17 December and at the end of January respectively (T. Lowe, Mystic Park, pers. comm.); 15 on 2 February (FWD), 1 on 7 March (F&GA) and 9 on 5 July (T. Lowe, pers. comm.). I found wings and feathers from 2 birds at the south end on 8 March and 6 bodies were reported to T. Lowe along 400 metres of the northern shore on 7 March. Lake Bookar: 500 ha, 38o07'S 143°07'E. Reports before opening were of 200 on 3 February (FWD) , 3 at the north end on 26 February and 19 on the entire lake on 27 February and 2 were seen, again on the whole lake, on 27 March. F&GA reports were of 100 (accumulative total) on 5 March, 4 on 7 March, 20 on 9 March and 2 during March. I found 1 corpse along a third of the shore on 12 March and 3 were seen on 7 March (F&GA). Booroopki Swamp: 420 ha, 36°44'S 141 o1 4'E 60 on 21 January 1981 (FWD). Lake Boort: 450 ha, 36°08'S 143 o44'E. 24 on 7 March (F&GA). Lake Buloke and Little Lake Buloke: 5600 ha, 36o18'S 142o56'E. Lake Buloke was dry by 7 March. I saw 250 on Lake Buloke on 26 January, 5-10 were reported (FWD) on 28 January and 1 on 9 February (F&GA). T here was one on Little Lake Buloke and 5 on the Lower Avon River nearby on 4 February (FWD). Five were reported at Donald, presumably on Little Lake Buloke, on 7 March (F&GA) . Lake Buninjon: 270 ha, 37"28'S 142°47'E. 3 on 23 February (FWD) . Lake Burn: 63 ha, 38°17'S 143°43'E. 50 on 24 February (FWD). Lake Burrumbeet: 2320 ha, 37°30'S 143 o38'E. 3 in March (F&GA). Lough Calvert: 560 ha, 38o 10'S 143°41'E. 30 on 23 December. Cardross Lake: 140 ha, 34o18'S 142o06'E. 1 corpse on 7 March (FWD). Chi/tern: birds reported within the 10' grid square centred on 36°05'S 146°35'E between 1 December and 28 February (RAOU). Lake Colongulac: 1510 ha, 38°10'S 143 °10'E. 200 on 3 February (FWD) ; 1 on 13 February (F&GA); 100 (FWD aerial count) and 90 at the north end on 26 February; 100 on 7 March (F&GA); 10 on 25 March and 6 on 12 June. It is also possible birds were moving between Lake Colongulac and Lake Bookar (F&GA). Lake Connewarre: 900 ha, 38°14'S 144o26'E. 1 shot on 9 March (FWD). Lake Coradgi/l: 93 ha, 38o06'S 143 o21 'E. 60 on 3 February (FWD). Lake Corangamite: 23300 ha, 38o 10'S 143o25'E. 50 were identified but 250 were estimated to be present on 3 February (R. Priest, FWD pers. comm.) and six were reported on 1 March (F&GA). R . Priest also spoke to 3 local residents who had each seen large flocks on different parts of the Lake at about the same time in early February so up to 3000 may have been present. However, since none was reported during aerial inspection of the northern, north-eastern and south-eastern shires on the 26 February or during visits to parts of the south-western and north­ eastern shores on 25 and 26 February, 250 seems a reasonable estimate of the number present immediately before opening. Wings and feathers of 3 birds were VOL. 9 (8) DECEMBER 1982 F reckled Duck in Victoria 263 found on the Lake shore west of Cororooke and from 1 at Piuon Yallock on the 11 March. Cullens Lake: 615 ha, 35°38'S 143 °46'E. 450 about 31 January (C. Doughty, BOC, pers. comm.); at least 500 on 14 February (a local shooter reported by T.