摘要:

SummaryAn examination of specimens revealed that the blue wrens,Malurusspp., emu wrensStipiturusspp., grass-wrens,Amytornisspp., and species of the New Guinea generaTodopsis, Chenorhamphus, andClytomyias, have the common morphological character of a gap in the interscapular zone of the spinal feather tract, this area being covered by longer feathers of the cervical and humeral tracts. This character provides a common link between genera which had been tentatively grouped together in an earlier paper, but excludesLamproliawhich had been provisionally placed with this group.Amytornis striatusandA. textilisshow an extremely close resemblance to some species of babblers of the generaGarrulax, Babax, andArgyain morphology and plumage pattern, and it is considered that this is an indication of relationship ofAmytornisto the Timaliidae. The behaviour ofAmytornisspp., in so far as it is known, resembles that ofMalurusspp. In the earlier paper it had been shown that the behaviour ofMalurusspp. was like that of babblers and did not resemble that of the thrushes, flycatchers, and warblers. In view of the additional evidence it is suggested that the six generaMalurus, Stipiturus, Amytornis, Todopsis, Chenorhamphus, andClytomyiasshould be regarded as an Australasian subfamily or tribe of the babblers, Timaliidae.

ISSN:0158-4197    

DOI:10.1071/MU969001

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

SummaryThe Papuan and Little Cuckoo-Shrikes have always been regarded as distinct species,Coracina papuensisandC. robusta, because the latter is supposed to have a distinctive melanic plumage when immature, and more recently because of a supposed overlap in range. However, it can be shown that the melanism is not confined to a particular plumage, and does not sharply distinguish between populations, while there is no evidence of an overlap in breeding ranges. The slight differences between neighbouring populations of the two forms distinguish them only as geographical races ofCoracina papuensis.This species, centred on New Guinea, is represented in Australia by three races, of whichrobustais much less distinct thanhypoleuca, the White-breasted Cuckoo-Shrike. The melanism, which is virtually confined to the southern populations ofrobusta, is exceptionally variable in extent.

ISSN:0158-4197    

DOI:10.1071/MU969009

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

摘要:

SummaryRecords of birds additional to the pair helping at single nests in Australian passerine species are summarized. This behaviour is known to occur in the Ground Cuckoo-Shrike, the Yellow-tailed Thornbill, the blue wrens, the Sittella, four species of honeyeater, the White-winged Chough and Apostlebird, the woodswallows, and the Pied Butcher-bird; and there is a likelihood of its occurrence in the babblers. The proportion of birds showing the behaviour is high in comparison with other avifaunas and it is probably due to some common factor, the likeliest being climate. In species such as the blue wrens, which are rather sedentary, this behaviour can help to maintain the population at a high level in a poor habitat by ensuring nesting success. In other species small nomadic parties are more likely to discover suitable areas, and to contain a breeding pair, while additional birds help in nesting and the rearing of young and can also act as replacements for lost members of the dominant pair.In the Australian species the helpers are often adults apparently capable of breeding and it seems possible that the behaviour could have been evolved in adults, and not from immature individuals assisting at the nest, as suggested by Skutch for other regions. Selection for such behaviour could occur if it is assumed that the dominant pair pass on to their offspring the dual capacity to act as a member of a dominant pair or as a helper in different situations. The reduction or loss of male breeding plumage in subordinate males in the blue wrens might help to prevent the arousal of aggressive reactions associated with such plumages. There appears to be no information available concerning possible factors which inhibit breeding behaviour in subordinate birds or determine the selection of dominant individuals.

ISSN:0158-4197    

DOI:10.1071/MU969030

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU969041

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU969044

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU969047b

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU969047c

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU969047e

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU969047f

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor

ISSN:0158-4197    

DOI:10.1071/MU969054

出版商:Taylor&Francis    

年代:1969

数据来源: Taylor