摘要:

SUMMARYWINGHAM, E.J. 1984. Breeding biology of the Australasian GannetMorus senator(Gray) at Motu Karamarama, Hauraki Gulf, New Zealand I. The egg. Emu 84: 129–136.Breeding biology of the Australasian Gannet was studied over three breeding seasons (1978–80). The nest sites and density, first date and duration of egg-laying, median date of laying, clutch size and replacement laying, incubation period and egg dimensions, were measured. Similar information is available for the Atlantic Gannet and the Cape Gannet, allowing comparisons between the three Gannets to be made.The Australasian Gannet varies more in the first and median dates of laying than the Atlantic Gannet. This is thought to be related to weather and food supply. Most Australasian Gannet eggs that are lost are lost and replaced after three- quarters of the spread of laying has elapsed. In the Atlantic Gannet eggs are mostly lost and replaced before the mid-laying date. The Australasian Gannet has a proportionally larger egg than the Atlantic Gannet. These differences probably result from the Australasian Gannet experiencing a less seasonal and predictable environment than the Atlantic Gannet.

ISSN:0158-4197    

DOI:10.1071/MU9840129

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

摘要:

SUMMARYWOINARSKI, J.C.Z. 1984. Small birds, lerp-feeding and the problem of honeyeaters. Emu 84: 137–141.Honeyeaters often defend rich sources of carbohydrates such as nectar and lerps (exudates of psyllids). Lerps are also a major food item of pardalotes, and consequently these birds are attacked frequently by honeyeaters, especially in winter and spring. Up to 5% of daylight time and 9% of energy expended may be wasted by pardalotes escaping from honeyeaters. This susceptibility to attack may have been influential in the development of hole-nesting by pardalotes and may have deterred other small foliage-gleaning birds from eating lerps.

ISSN:0158-4197    

DOI:10.1071/MU9840137

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

摘要:

SUMMARYBELL, H.L. 1983. A bird community of lowland rainforest in New Guinea. 6. Foraging ecology and community structure of the avifauna. Emu 84: 142–158.The foraging ecology and community structure of 83 co-existing species at Brown River, Papua New Guinea, were analysed. Obligate carnivores, mostly insectivorous, are much more diverse in foraging behaviour than are facultative carnivores. Overlap between insectivorous species may be lower than in similar but depauperate communities in Australian rainforests. Herbivores are separated mostly by differences in weight. Carnivores do not conform to current theory on size-differences between co-existing congeners. It is suggested that the two opposing views, explaining the richness of tropical avifaunas, are both correct. For herbivores the abundance of resources permits wide overlaps between species. For carnivores the complex habitat permits many species to co-exist by finely dividing the habitat.

ISSN:0158-4197    

DOI:10.1071/MU9840142

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

摘要:

SUMMARYCOLLINS, B.G., P. BRIFFA and C. NEWLAND. 1984. Temporal changes in abundance and resource utilization by honeyeaters at Wongamine Nature Reserve. Emu 84: 159–166.White-cheeked and Brown Honeyeaters,Phylidonyris nigraandLichmera indistincta, were counted in the only section of the Wongamine Nature Reserve whereBanksia prionotesoccurs, between January and June, 1982. Abundances of both honeyeater species in a central patch of theB. prionoteswere correlated with the numbers of inflorescences or flowers present in the patch and elsewhere. In January, when fewB. prionotesinflorescences were open, birds were rare and generally foraged at flowers of other plant species in the surrounding vegetation. Numbers ofL. indistinctain the patch were still low in February, although the abundance ofP. nigrahad increased significantly. Honeyeaters were most numerous in the central patch in March and April, when open inflorescences and nectar were abundant on mostB. prionotesbushes. Despite the relatively large standing crops of nectar available per inflorescence at dawn in May, few honeyeaters visited the patch at this time. Birds switched their attention to other plant species that had more flowers and offered larger volumes of nectar than in previous months. Arthropod availability did not appear to directly influence the abundance or distribution of honeyeaters in this region.

ISSN:0158-4197    

DOI:10.1071/MU9840159

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

摘要:

SUMMARYS. MARCHANT. 1984. Nest-records of the Eastern Yellow RobinEopsaltria australis.Emu 84: 167–174.Seven hundred and seventy nest-record cards of the Eastern Yellow RobinEopsaltria australiswere available at the end of the 1980–1 breeding season, about one-quarter being from the Moruya district of New South Wales. They provided details but little new information on habitat, nests and nest sites, except that the birds probably nest high in forest trees more often than was supposed. Laying was at intervals of about 27 hours. Clutch size averaged 2.33 without any detectable differences between years, places or altitudes but increasing from 2.16 before to about 2.5 after October. The incubation period was just under 16 days and the nestling period 10–14 days. Breeding success was about 30%, apparently decreasing from 33% before October to about 20% in November and December; the most frequent clutch size (2) was most frequently successful but clutches of three raised more young per nest than did clutches of two. The breeding season started at the end of July or in early August and stopped quite abruptly at the end of December, with the main peak of laying from mid-September to mid-October. More nests were started before 31 August in Victoria than at Moruya. The analysis was dominated and distorted by the quantity and quality of records from Moruya and few useful comparisons could be made between the results from there and from elsewhere.

ISSN:0158-4197    

DOI:10.1071/MU9840167

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9840175

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9840178

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9840181

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9840183

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9840185

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor