ISSN:0158-4197    

DOI:10.1071/MU9800251s

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1080/01584197.1981.11799285

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

SUMMARYPruett-Jones, S. G., C. M. White and W. R. Devine. 1981. Breeding of the Peregrine Falcon in Victoria, Australia. Emu 80: 253–269.This study was conducted from September to December, in both 1976 and 1977, to investigate the demography and ecology of the Victorian Peregrine Falcon. At least 200 nesting areas were discovered and we report data on ninety-five sites throughout the State. The most common nest site (62 of 95) was a cliff (vertical escarpments, stone quarries and rocky knolls). Nest sites in trees were in hollows (17) and in stick nests of other birds (16). Extreme variation in selection of nest sites was observed. Exposure of cliff sites was significantly related to fledging success.Laying began in late August and the last young fledged in early December. The onset of breeding in 1977 was seven to ten days earlier than in 1976 in correlation with warmer drier conditions that spring. Clutch size averaged 2.81 and brood size, 2.24, for all sites hatching young. Over half (59.8%) of the occupied sites fledged young for a net productivity of 1.21 young per occupied site (2.02 young per successful site). Non-breeding adults occurred at 15.2 per cent of the occupied sites.Prey consisted of small to medium sized birds and a few mammals. Eighty-nine species of bird were identified as prey but three (Feral Pigeon 20%; Galah 15%; and Common Starling 16%) were the most important. Parrots as a group made up thirty-six per cent of the diet.Results are discussed in light of studies of Peregrines from northern temperate areas and comparisons made regarding breeding schedules, productivity and selection of nest sites. The Victorian Peregrine appears more adaptable to variation in habitat than most populations and, at least superficially, stability of the population is suggested by most aspects of its breeding ecology.

ISSN:0158-4197    

DOI:10.1071/MU9800253s

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

SUMMARYWhite, C. M., S. G. Pruett—Jones and W. B. Emison. 1981. The status and distribution of the Peregrine Falcon in Victoria, Australia. Emu 80:270–280.Between 1974 and 1979 two hundred and seventeen historical, active or probable nesting sites of Peregrine Falcons were documented in Victoria. A conservative estimate of the total population is 300 to 350 breeding pairs. Nests on cliffs predominate with stick nests in trees and nests in hollows in trees in about equal proportions. The tree nests usually occurred where cliffs were not present but may also occur with cliffs nearby. Some regions such as the Little Desert and Alpine area are poorly studied and may contain more eyries than at present known. The density of Peregrines in Victoria may be about one pair per 650 to 750 square kilometres based on known values for various parts of the State. Thus, Victoria may have a density similar to those of continental Europe before the late 1940s. Availability of food may be the overriding limiting factor but local lack of nest sites or suitable area on existing sites (cliffs) may also restrict breeding. Also locally abundant and easily caught food, mainly columbiformes and psittaciformes, may be the prime factor allowing nesting in Some seemingly otherwise unsuitable locations. In Victoria there is probably no competition for nesting on cliffs with other raptors but other tree-nesting congeners may compete for trees. Local traditions in nest site selection may also affect the population but this has yet to be tested. Factors in selecting nest sites should be studied further. The Peregrine generally seems to be holding its own in Victoria in the face of human encroachment.

ISSN:0158-4197    

DOI:10.1071/MU9800270s

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

SUMMARYPruett—Jones, S. G., C. M. White And W. B. Emison. 1981. Eggshell thinning and organochlorine residues in eggs and prey of Peregrine Falcons from Victoria, Australia. Emu 80:281–287.The Peregrine Falcon in Victoria is common for a raptor, breeds in most habitats and at a variety of sites and has moderate reproductive success. However, breakage of eggs, loss of clutches and abnormal behaviour of some adults are salient characteristics of the population. Between 1975 and 1977 we collected thirty—five eggs from twenty—six eyries and forty-three individuals of thirteen species of prey for analysis of chlorinated hydrocarbons. Eggshell index averaged 1.52, indicating a 20.4 per cent reduction in shell index from eggs collected before 1952. DDE content of eggs ranged from 2.30–82.00 ppm wet weight (mean 17.63). Polychlorinated Biphenyls and Dieldrin were present in most eggs but at low levels. Residues of DDE for prey were low (mean 0.11 ppm) but were highest for two of the most important species in the diet of the Peregrine: Feral Pigeon and Common Starling. Despite rather low use of DDT in Victoria, residues in important prey, specially the Pigeon, are sufficiently high to produce the reproductive failure observed. The significance of this failure to the population of Peregrines is unclear. Its apparent stability probably results from a large population in the past; a future population reduction may occur if eggs continue to be lost at the present rate.

ISSN:0158-4197    

DOI:10.1071/MU9800281s

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

摘要:

SUMMARYEmison, W. B., and W. M. Bren. 1981. Banding of Peregrine Falcon chicks in Victoria, Australia. Emu 80: 288–291. Of 212 Peregrine Falcon chicks banded in Victoria during eleven years, 1960–62 and 1972–79, sixty-nine per cent were from eyries on cliffs, the rest from eyries in trees. The distribution of chicks banded at the different types of eyrie is shown in relation to the study areas of the Land Conservation Council of Victoria. Fifty-five per cent of the chicks banded were from only fifteen of sixty eyries where chicks were banded. By March 1980, twelve bands had been recovered, all in Victoria. Most bands were from birds less than one year old. Identifiable causes of death or injury were shooting and being struck by vehicles; one banded Peregrine was seen to hit a wire during a stoop.

ISSN:0158-4197    

DOI:10.1071/MU9800288s

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1080/01584197.1981.11799290

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1080/01584197.1981.11799291

出版商:Taylor&Francis    

年代:1981

数据来源: Taylor