摘要:

A very distinctive perdicine bird was discovered in July 1991 during fieldwork in montane evergreen forests in parts of the Udzungwa Mountains in Tanzania which were so far ornithologically unexplored. The bird is described here as a new genus and species with affinities to the hill‐partridgesArborophilaof the Indo‐Malayan region. The relict occurrence in Africa of taxa with affinities to Oriental biota is discus

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08125.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The past decades have been exciting ones for ornithologists interested in avian macrosystematics with many new ideas being proposed for consideration and further study. But this excitement should not blind ornithologists to the important distinction between the provisional classifications proposed by specialists in macrosystematics, no matter how convincing they may appear at first glance, and the standard sequence needed to maintain optimal communication among all students of avian biologists. An excellent standard sequence for Recent birds exists in Peters'Check‐list. We urge that all ornithologists, authors and editors use this sequence until the time arrives, as it undoubtedly will, when enough is known about avian relationships to permit agreement on a new and better standard sequenc

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08126.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The diet composition of Emperor PenguinAptenodytes forsterichicks was examined at Auster and Taylor Glacier colonies, near Australia's Mawson station, Antarctica, between hatching in mid‐winter and fledging in mid‐summer by “water‐offloading” adults. Chicks at both colonies were fed a similar suite of prey species. Crustaceans occurred in 82% of stomach samples at Auster and 87% of stomachs at Taylor Glacier and were heavily digested: their contribution to food mass could not be quantified. Fish, primarily bentho‐pelagic species, accounted for 52% by number and 55% by mass of chick diet at Auster, and squid formed the remainder. At Taylor Glacier the corresponding values were 27% by number and 31% by mass of fish and 73% by number and 69% by mass of squid. Of the 33 species or taxa identified, the fishTrematomus eulepidotusand the squidPsychroteuthis glacialisandAllu‐roteuthis antarcticusaccounted for 64% and 74% of the diets by mass at Auster and Taylor Glacier, respectively. The sizes of fish varied temporally but not in a linear manner from winter to summer. Adult penguins captured fish ranging in length from 60 mm (Pfeura‐gramma antarcticum) to 250 mm (T. eulepidotus) and squid (P.glacialis) from 19 to 280 mm in mantle length. The length‐frequency distribution ofP. glacialisshowed seasonal variation, with the size of squid increasing from winter to summer. The energy density of chick diet mix increased significantly pr

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08127.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

In 1974–1975, 34 adult South Polar SkuasCatharacta maccormickiwere colour‐ringed on 18 nest territories at Bonaparte Point, Anvers Island, near Palmer Station along the Antarctic Peninsula. Subsequently, the area was searched for these birds during the austral summers of 1975–1976 to 1984–1985 and in 1987–1988 and 1989–1990. Fifty‐three percent were seen in 1984–1985, 32% in 1987–1988 and 21% in 1989–1990. Annual survival rate averaged 95% from 1974–1975 to 1984–1985; no sexual differences were detected (n = 28 of known sex). Strong territory and mate fidelity were apparent: 34 skuas averaged 1.1 nest territories and 1.7 mates each in 16 years. Only 4 of 34 individuals (all females) were known to change territories, and each territory change involved a change of mates. Although males showed higher territory fidelity than females (P<0.01), most females (four of five) retained their territories when previous mates failed to return. Seventeen of 34 birds changed mates a total of 24 times; at least 20 mate changes followed the death or disappearance of the former mate. Males showed slightly higher mate fidelity than females (P<0.04). Female South Polar and Brown SkuasCatharacta lonnbergidid not differ in territory or mate fidelity. From 1974–1975 to 1984–1985, 120 South Polar Skua chicks were ringed on 18 nest territories on Bonaparte Point: 17 were resighted in the Palmer area when they were 3–10 years old. All 15 returnecs were found within 3 km of their natal nest sites, and four of them occupied nest t

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08128.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Between‐season differences in habitat use by Black GrouseTetrao tetrixwere studied on four moors in the northern Pennines between 1989 and 1992. Heather moor and bogs were preferred at all times of the year, apart from during the breeding season. In spring, large quantities of Cotton‐grassEriophorum vaginatumflowers were consumed, whereas in autumn and winter HeatherCalluna vulgariswas more important. Enclosed fields on the edge of the moors were regularly used in autumn and winter by large flocks of cock birds, and hens were found in smaller groups. Where present, overgrazed grass moorland was generally avoided, apart from during the summer. Similarly, enclosed rough grazing allotments rich in rushes were favoured during the summer months by breeding hens and moulting co

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08129.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Samples of up to ten study skins for each of five species ofMicrohierax, two species ofPolihierax, one species ofSpiziapteryxand 23 species of smallFalcowere measured for 24 dimensions of the head, wings, tail and feet. The logarithmic (log10) valucs of the means of each mcasurcmcnt for each species, and for each sex where dimorphic, were compared using cluster and factor analyses.Microhieruxfalconets are most similar to the African Pygmy FalconPolihierax sernitorquatusbut are morphometrically distinct from all other falconets and smallFalcospecies. The five species of Microhierax falconets are morphometrically similar, sexually dimorphic and probably replace one another ecologically, since all are allopatric or differ in proportions and habitat where parapatric (two species). Prelim[nary observatioris on the hunting behaviour and social organization of the Rlack‐thighed FalconetMicrohierux fringillariusindicate that the genus has morphological and social specializations for aerial capture of large forest insect

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08130.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08131.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The timing of primary‐feather development in relation to growth in body‐mass varies considerably between altricial species. This variation relates, at least in part, to differences in nesting habits: species nesting in relatively well‐protected nest sites, such as holes, start primary‐feather development later than altricial species using open‐cup nests. For the latter ‘open‐nesting’ species, the timing of primary‐feather development also tends to show an allometric correlation with adult body‐size. Since primary‐feather development takes longer, rerative to growth in body‐mass, in small species than in large ones, these data suggest that, for small species, there will be an important selective advantage in using relat

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08132.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Ranges of individual males of three hornbill species were determined by radio telemetry during the breeding and non‐breeding seasons in Khao Yai National Park, Thailand. Two Great HornbillsBuceros bicornisand two Brown HornbillsPtilolaemus tickelliwere studied in both 1988 and 1989, and two Wreathed HornbillsRhyticeros undulatuswere studied in 1989, 1990 and 1991.In the breeding season, the home range of the Great Hornbill was 3.7 km2, similar to that of the Brown Hornbill (4.3 km2), while the Wreathed Hornbill occupied the largest home range (10.0 km2). In the non‐breeding season, the range size of the Wreathed Hornbill (28.0 km2) was greater than that of the Great Hornbill (14.7 km2). Differences in range sizes of different species may be related to differences in diet and breeding strategy. Ranges overlapped within and between the species, and this has implications for the estimation of the minimum area required for the conservation of hornbills within the Khao Yai National P

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08133.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

The breeding population of the Spanish Imperial EagleAquila adalbertiis reduced to 126 pairs located in the southwestern quadrant of the Iberian Peninsula. Protein electrophoresis was used to determine levels of genetic variation in the seven extant subpopulations of the species. Seventeen proteins encoded by 22 putative loci showed no variation among all the individuals which were analysed. The population crashed at the beginning of this century, but the long generation time of the species makes it improbable that a population bottleneck was the only cause of the lack of genetic variation. As an alternative explanation, a natural background of low variation cannot be discounted.

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1994.tb08134.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY