摘要:

SummaryThe diets of sympatric Barn OwlsTyto albaand Australian KestrelsFalco cenchroideson islands off the coast of Western Australia were studied by pellet analysis. House MiceMus domesticuscomprised the bulk of the diet of the Barn Owl (83% by volume), with other species of small mammals and birds constituting most of the remainder of the diet. In contrast, reptiles and insects were the major prey categories in the diet of the Australian Kestrel (38% and 39%, respectively, by volume), with small mammals and birds constituting 23%. The dietary differences between the two species reflect the diurnal hunting activity of the Australian Kestrel and nocturnal hunting, especially for mice, in the Barn Owl.

ISSN:0158-4197    

DOI:10.1071/MU9910069

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

SummaryColour-banded populations of White-throatedCormobates leucophaea, Red-browedClimacteris erythropsand Brown TreecreepersCI. picumnuswere studied for up to six years in north-eastern New South Wales. All species are sexually dimorphic, insectivorous and nest in tree-holes. The White-throated and Red-browed are totally arboreal and nearly identical in size while the Brown spends half of its time on the ground and is about 50% larger than the other two species. The non-cooperative White-throated held small individual or pair territories which were vigorously defended but not stable over the study period. Offspring were evicted from the natal territory when independent and very few were seen again on the study sites. Cooperatively breeding Red-browed and Brown Treecreepers lived in pairs or groups which contained one breeding bird of each sex and up to three helpers. About one-quarter of the offspring of both species stayed on the study site for one year or more, and almost all were males. Helpers participated in nest construction, feeding of the incubating female, and feeding and defence of the young. Territories were larger, more static and less regularly defended than in the White-throated. Breeding success of the White-throated did not differ significantly from that of the Red-browed or Brown. However, within the latter two species, groups produced more young than pairs. Adult survivorship was higher in the Brown than in the White-throated where they co-existed. Survivorship of coexisting Red-browed and White-throated was similar, until the onset of a drought which had a greater negative effect on the latter. Group-living and cooperative breeding are probably related to specialised niche requirements and lack of suitable habitat in the patchily-distributed Red-browed, while in the widespread and semi-terrestrial Brown, predation appears to have played the major role. Roost-holes may be a limited resource for both cooperatively breeding species, favouring philopatry.

ISSN:0158-4197    

DOI:10.1071/MU9910073

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

SummaryThe contents of crops from 138Cacatua pastinatorcollected throughout Western Australia were examined. Abundances of the various food items reflected the land-use where the birds were collected. In the lower southwest,C. p. pastinatorate mainlyRomulea roseabulbs with moderate amounts ofAvena sativaandPoa annuaseeds whereas, in the wheatbelt the most frequent food for both C.p. pastinatorandC. p. gymnopsiswas wheatTriticum aestivumwithEmex australis, Hordeum vulgareandA. sativaas important items. The diets ofC. p. gymnopsisin the Murchison and Pilbara regions, andC. p. sanguineain the Kimberley region, were more diverse with native species predominating except for those specimens collected around towns and farms where mainly wheat, oatsA. sativaor sorghumSorghumsp. had been eaten. This and other studies, indicate that corellas have broad food preferences that enable them to exploit a wide variety of habitats including those altered by humans.

ISSN:0158-4197    

DOI:10.1071/MU9910087

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

SummaryThis five month study involved the daily observation of the contents of 83 occupied Fairy MartinHirundo arielnests under a large culvert near Murwillumbah N.S.W. Nest building occurred from July until 16 November. The average time taken to build nests was 30 days. Eggs were laid between 1 August and February. Clutch size varied from two to five and averaged 3.5 eggs. The range of egg sizes and colours are given. Incubation averaged 13.8 days (range = 11–17) and each pair successfully hatched an average of 3.3 nestlings early in the season and 3.0 nestlings later in the season. Clutch size, incubation period, hatching rate and the average number of hatchlings fledged from each brood, all declined in the last part of the season. The natal pterylosis, feather growth and growth rate of the chicks is described. Nestlings took an average of 22.5 days (range 14–30) to depart their nests. Predation and interspecific nest competition are recorded.

ISSN:0158-4197    

DOI:10.1071/MU9910093

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

SummaryIn an area severely burned by wildfire on 16 February 1983, a study, which had begun before the fire in spring 1982, was continued to determine recolonisation by birds. The study continued until spring 1988. Bird species were affected in different ways. Three patterns were apparent: no noticeable change; an initial decline followed by recovery after one or more years; and an increase following fire with a decrease coincident with plant regeneration. Of the 73 bird species recorded, 60% were present by the end of the first spring and 86% had been recorded by two years post-fire, which included all those present in the spring before the blaze. Population numbers took longer to recover. No control areas were available. The source of recolonisation was not evident. The danger of fire is most acute for birds restricted in habitat and distribution, such as the Rufous BristlebirdDasyornis broadbenti.

ISSN:0158-4197    

DOI:10.1071/MU9910100

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

SummaryIncubation was investigated in a wild population of Zebra FinchesTaeniopygia guttatain northern Victoria and comparisons made with wild-caught birds. A data logger recorded temperature readings from thermocouples inside eggs, nests, nesting bushes and exposed positions adjacent to nesting bushes. Both sexes incubate but only the female has a brood patch; this forms at the start of incubation and regresses soon after eggs hatch. Females incubated at night and both sexes shared incubation during the day. There were no consistent differences in the temperature of developing eggs heated by the two sexes nor did the sexes differ in their ability to rewarm cold eggs; fluctuations in incubation temperature also did not differ consistently between the sexes. Incubation began the day the fourth egg was laid for clutches≥5 or the day the last egg was laid for smaller clutches. Hatching was more synchronous in the wild than in captivity. The ability of the nest to maintain a temperature differential was limited: air temperatures in the roof of the nesting chamber of enclosed roosting and breeding nests followed ambient temperatures closely when conditions were mild but the nest provided an insulating effect that ameliorated low temperatures.

ISSN:0158-4197    

DOI:10.1071/MU9910107

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9910121

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9910122

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9910125

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9910126

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor