摘要:

SummaryEggshell thickness of 32 species of Australian raptors, relative to DDT use, was investigated. Nine species showed a significant reduction in shell thickness since DDT was introduced to agriculture in 1946: Whistling KiteHaliastur sphenurus; Brahminy KiteHaliastur indus; White-bellied Sea-EagleHaliaeetus leucogaster; Marsh HarrierCircus aeruginosas; Collared SparrowhawkAccipiter cirrhocephalus; Peregrine Falcon Falco peregrinus; Grey FalconFalco hypoleucos; Australian HobbyFalco longipennis; and Southern BoobookNinox novaeseelandiae.Average reductions in thickness ranged from 2% (Collared Sparrowhawk and Australian Hobby) to 10% (Peregrine Falcon). These levels are unlikely to be causing widespread population declines. However, several clutches from these species were so thin (maximum thinning ranged from 15% for the Grey Falcon to 45% for the Whistling Kite) that they were likely to break during incubation. Thus, localised breakage of eggs and reproductive failure has probably occurred. In general, bird-eating raptors and those living in areas of intensive agriculture were worst affected. Ostensibly, DDT consumption declined from a peak in 1973 to none in 1989. Reduction in shell-thickness occurred as early as 1947 and was greatest throughout the 1970s and 1980s. The uncontaminated eggs of owls were thinner than those of other raptors, perhaps partly reflecting the owls' lower absorption of dietary calcium (bone).

ISSN:0158-4197    

DOI:10.1071/MU9930001

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

SummaryThirteen active Ribbon-tailed AstrapiaAstrapia mayerinests were examined in forests of Tari Gap, Southern Highlands, Papua New Guinea. Most were in isolated small trees and often in secondary growth, possibly to reduce predation. A uniquely female-plumaged parent at one nest enabled us to confirm uniparental, assumed female, nest attendance. Nests and single egg clutches are decribed, and are typical of Paradisaeinae. One nestling first departed the nest at 26 days and finally at 30 days old, and its growth and development are described. Nesting was observed during October to February inclusive. Of identified nestling meals 67% were of fruit and 33% animal foods. Of identifiable nestling fruit meals 66% were ofSchefflerafruit pieces; 74% of nestling faecal samples included this fruit. Results of 19 h observation of incubation and 66 h of nestling care activity are presented. Nidification of congeneric species is reviewed.

ISSN:0158-4197    

DOI:10.1071/MU9930012

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

SummaryTwo active and three disused nests of the Crested Bird of ParadiseCnemophilus macgregoriiwere found in mixed montane beech forest in Papua New Guinea, and their situations and measurements are described. Fragments indicate that egg colour is pinkish-buff irregularly blotched with darker colours, similar to other paradisaeidine eggs. A nest and egg long ascribed to this species is considered wrongly identified. Hatchlings are typical of birds of paradise and unlike those of bowerbirds (Ptilonorhynchidae). Nestling care is by a single female-plumaged, presumed female, parent that feeds only regurgitated fruits. One nestling left the nest at 30+ days. Available data indicate a single egg clutch, a nesting season of September—February inclusive, and thatC. macgregoriiis a polygynously breeding bird of paradise.

ISSN:0158-4197    

DOI:10.1071/MU9930023

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

SummaryA comparison is made of breeding by Welcome SwallowsHirundo neoxenain eastern and western Australia and nestlings in recently colonised New Zealand. In all areas only the female incubated and brooded but the male helped feed the chicks and took away more faecal sacs than the female. Growth rates and pterylosis are described. Clutch sizes averaged 4.5 in New Zealand, 3.7 in eastern Australia and 3.2 in Western Australia and most hatched over a two day period. Average New Zealand incubation took 16.7 days and in eastern Australia took 16.0 days. Average nestling period in New Zealand of 21.5 days was significantly longer than the average Australian time of 18.9 days. The most productive clutch size produced: 5.0 fledglings (C/6) in New Zealand, 4.2 fledglings (C/6) in eastern Australia and 3.3 fledglings (C/4) in Western Australia. Although the species is new to New Zealand and has a larger clutch size there, total breeding success was not greater than that of Australian birds.

ISSN:0158-4197    

DOI:10.1071/MU9930034

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

SummaryThe logrunnersOrthonyxare a distinctive endemic Australo-Papuan group represented by two living species from eastern Australia and highland New Guinea, and two fossil species known from Quaternary deposits of southern Australia. The peculiar feeding method of logrunners gives their femora a distinctive appearance that is diagnostic for the genus. New material from Riversleigh, northwestern Queensland, extends the chronological range into the Miocene and increases the known geographical distribution of the genus. Living species inhabit rainforest and contiguous dense vegetation; structurally similar habitats have been interpreted for the fossil species. The presence ofOrthonyxat Riversleigh supports vegetation reconstructions for this area during the Tertiary.

ISSN:0158-4197    

DOI:10.1071/MU9930044

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9930050

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9930053

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9930059

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9930063

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor