摘要:

SummaryBlaber, S.J.M. (1990). A checklist and notes on the current status of the birds of New Georgia, Western Province, Solomon Islands.Emu90, 205–214.A checklist of the birds of New Georgia was compiled over three years from December 1985 to August 1988. A total of 70 species were recorded. Seven habitat types were recognised: (1) primary forest, (2) secondary forest, (3) open areas, (4) villages, gardens and plantations, (5) mangroves, (6) shorelines, and (7) marine. Species observed in each of these habitats were rated as abundant, common or present. The majority of species occurred in primary forest (33 species) and secondary forest (29 species). The present species composition is compared with that recorded by the Whitney South Sea Expedition in the 1930s and by Sibley in 1945. Eight species found in the 1930s and three in 1945 were not observed in this survey but two species(Gallirallus philippensisandAceros plicatus) were recorded for the first time on New Georgia. Changes in the species structure of the avifauna is discussed in relation to loss of primary forest caused by logging and industrial development. It is concluded that while considerable species diversity may be maintained, a number of species confined to undisturbed forest are endangered.

ISSN:0158-4197    

DOI:10.1071/MU9900205

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryBrooker, M.G., Braithwaite, R.W.&Estbergs, J.A. (1990). Foraging ecology of some insectivorous and nectarivorous species of birds in forests and woodlands of the wet-dry tropics of Australia.Emu90, 215–230.The foraging ecology of 40 species of insectivorous and nectarivorous birds was studied in the monsoon forests, woodlands and open forests of the Kakadu National Park, Northern Territory. Most used a broad range of foraging heights, sites and behaviours. The more specialised species were usually terrestrial or aerial feeders. When taking invertebrates, honeyeaters used a narrower range of foraging strategies than did obligate insectivores. The degree of potential overlap in foraging ecology between species pairs was not related to abundances or morphological similarities. Food-related morphological characters of a species were not strongly related to its foraging ecology. The generalised foraging mode of most species and the apparent lack of interspecific competition are probably attributable to the climatic variability found in this region.

ISSN:0158-4197    

DOI:10.1071/MU9900215

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummarySmith, L.H. (1990). A method for determining the curvature of natural forms and its application to certain tail feathers of the Superb LyrebirdMenura novaehollandiae. Emu90, 231–240.A method for determining the curvature pattern of a two-dimensional curve is described and demonstrated by its application to three types of tail feathers of the Superb Lyrebird. Assuming that the curve is part of a circle, the straight line AB joining the ends A and B of the curve is a chord of that circle. The perpendicular bisector of the chord AB passes through the centre of the circle 0 and meets the curve (circle) at C, and at D, a distance of 2R from C, where R is the radius of the circle. Because DOC is a diameter of a circle, angle DAC (= angle DBC) equals 90 degrees (Euclidean theorem) and AC (= BC = L)/2R = Cosθ, whereθis the angle between AC and DOC. Thus, R = L/2 Cosθ. The paper describes how L andθare measured. Extension of the method to the shorter elements resulting from the first step enables a curvature pattern for the entire curve (feather) to be determined. The plain median rectrix of a Superb Lyrebird, and the median and lyrate rectrices of a mature male Superb Lyrebird, were all more highly curved at the distal end.

ISSN:0158-4197    

DOI:10.1071/MU9900231

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryCongdon, B.C. (1990). Brood enlargement and post-natal development in the Black NoddyAnous minutus. Emu90, 241–247.The ability of the Black Noddy to raise an artificially enlarged brood and the effect of brood enlargement on prefledging growth and mortality were examined on Heron Island during the 1983–84 breeding season. Where chicks from enlarged broods were the same age brood enlargement did not affect nestling growth or mortality. This suggests adults were able to compensate for the increased energy requirements of a second brood member. Reproductive output from enlarged broods was not limited by the total quantity of food available, or by the ability of adults to find and transport this food. Where chicks were different ages intra-brood competition reduced the amount of food obtained by younger chicks, causing a retardation of flight feather development. A slowing in wing development was not accompanied by a reduction in the rate of weight increase. Feather development slows before starvation is apparent; this suggests wing growth may be modified so fiat nutrients essential for body maintenance and the growth of soft tissue are available during periods of low food availability. In the Black Noddy maximum body weight is attained significantly earlier than full wing length. Differences in the rate of weight and wing length increase, the ability of adults to raise an enlarged brood and the further slowing of only feather development during food stress, suggest that‘normal’wing development in this species may be adjusted to some minimum level of a fluctuating food resource, rather than to consistently low levels of food availability. Such a mode of development can be interpreted as an adaptive response to large variations in the quantity of food obtained at any one feeding and/or the extended period of time between consecutive feeding bouts.

ISSN:0158-4197    

DOI:10.1071/MU9900241

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryKing, B.R. (1990). Distribution and status of the Torresian Imperial PigeonDucula spilorrhoain north-eastern Queensland: Cooktown to Cape York.Emu90, 248–253.The sizes of 95 Torresian Imperial Pigeon colonies were estimated on 139 islands between Cooktown and Cape York, Queensland. Six colonies exceeded 10 000 pairs, 29 contained between 1000 and 10 000 pairs, 60 colonies contained fewer than 1000 pairs, and 44 islands had no breeding. Mangroves are the preferred breeding habitat and coastal low wooded islands support most of the largest colonies and breeding population. The status of the study area population is compared with those in the rest of Queensland, the Northern Territory and Western Australia. The area between Cooktown and Cape York supports the largest population and colonies of Torresian Imperial Pigeons in tropical Australia, and has large areas of undisturbed mainland rainforest feeding habitat. Current levels of protection of the species are examined. Management procedures should include: protection of the major colony islands and feeding habitat north of Cooktown; prevention of hunting and human disturbance; and a joint approach with Paupa New Guinea and Indonesia to manage this migratory species.

ISSN:0158-4197    

DOI:10.1071/MU9900248

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryFrith, C.B.&Frith, D.W. (1990). Nidification of the Chestnut Forest-RailRallina rubra(Rallidae) in Papua New Guinea and a review ofRallinanesting biology.Emu90, 254–259.Nests, eggs and chicks of the Chestnut Forest-RailRallina rubraare described for the first time, from Tari Gap, Southern Highlands Province, Papua New Guinea. The nest is a large globular or domed structure of moss, leaves and ferns with a side entrance, typically placed some 2 m high in a pandanus palm crown (n= 20). The clutch is a single egg, unlike other rail clutches, and the egg is very large, being proportionately greater in mass to the bird than in any other rail so documented. Both sexes incubate but eggs are often left to become cold. Incubation in one nest was at least 34–37 days, being much longer than the incubation period of the only congener or of any other rail known. Nesting biology ofRallinaspp. is reviewed.

ISSN:0158-4197    

DOI:10.1071/MU9900254

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

SummaryBamford, A.R., Davies, S.J.J.F.&van Delft, R. (1990). The effects of model power boats on waterbirds at Herdsman Lake, Perth, Western Australia.Emu90, 260–265.The study shows that the use by waterbirds of those parts of Herdsman Lake used for racing model power boats remained at a level comparable with that of other parts of Herdsman Lake. We consider that the racing of model power boats, at its present levels of intensity and frequency, is not detrimental to waterbirds in the long term. On days when model boats

ISSN:0158-4197    

DOI:10.1071/MU9900260

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9900266

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9900269a

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU9900272

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor