ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02621.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.The land birds seen on St Vincent in 1971 are listed.Chaetura martinicais resident in the rain forest. Two‐fifths or more of the land birds occur in both lowland and highland woodlan

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02622.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.Resident and transient birds seen on Grenada in 1971 are listed.Leptotila wellsistill persists.Apus apusis new for the West Indies. Nearly half the resident land birds are regular in both lowlands and highlands.

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02623.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.The Barn Swallow is a non‐breeding winter visitor to West Malaysia (Malaya), abundant in season, by day feeding aerially over a wide range of habitats and by night normally roosting gregariously in trees, reed‐beds or on service wires in towns. Records of ringed birds have demonstrated that those reaching Malaya breed in the Palaearctic region from 108°E eastwards between 37° and 51°N. Recoveries south of the breeding range suggested that migrating birds may follow either a continental route or a more easterly track through the Philippines and Borneo. Counts at roost sites in a reed‐bed and in towns demonstrated a seasonal increase in numbers from late July to a peak in November, followed by a decline of about 20% to a level maintained until mid‐February when departure commenced. Most birds had left by early May, but a few lingered and possibly overlapped with the first returning migrants in June. There was no evidence that any individuals remained in Malaya through the nuptial period. Repeats during winter at three regularly sampled urban roosts indicated that many birds on passage were present until November and again in late March–early April; from December to February the winter population was relatively stable and comparatively sedentary. Although the distances between towns were small in relation to the demonstrated foraging range of Barn Swallows, only 17% of 1,955 repeats of ringed birds represented a shift in roost site. Most shifts were towards the centrally situated and most populous roost of the three; interchanges between the outer pair of towns were few.A complete moult occurred on the wintering grounds, during which young of the year acquired adult plumage. Replacement of the primaries extended virtually throughout the moulting period, at an average rate of 2.4 feathers per month in the proximal part of the tract and 1.3 feathers per month in the distal part. Adults on average moulted slightly earlier than juveniles, but there was a wide scatter in timing between individuals of both age groups. There was no evidence that the initiation of moult was related to the dates of post‐nuptial migration. The date of departure on prenuptial migration, however, was normally delayed until primary moult was complete. Large weight gains in March and April occurred only in swallows which had completed the moult. At this period the mean weight of birds in fresh plumage was about 30% above the lowest winter mean, and was significantly higher than that of contemporary samples of birds in which moult was continuing. In final samples in late April and early May mean weights showed a decline, indicating that late birds departed with reduced deposits of metabolic reserves.The gonads of adults of both sexes among passage and arriving birds in July and August had largely completed post‐nuptial regeneration, and subsequently remained quiescent. Preliminary stages of recrudescence were observed in females from February onwards, and in males from March. Recrudescence was most advance in specimens which had completed the moult, but did not approach breeding condition in any bird before departure.Returning birds tended to be conservative in their choice of winter roost. Among 1,276 records, 82% were recaptured in the town of original ringing. Again shifts towards the centrally situated roost were more numerous than between the peripheral pair. The frequency of returns varied significantly with the month of ringing, being higher for December‐March, lower for July‐November and April‐May. Survival rates, calculated from returns after one and two breeding seasons, indicated an annual mortality of 60–72%, higher among juveniles than adults. Comparison of results of successive years suggested that unfavourable conditions in 1967 resulted in lower survival of juveniles in particular than in 1966. There was no evidence of mortality at the roost sites, and it is argued that heavy losses probably occur durin

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02624.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.A survey of the frequency of the dark and light colour forms of the Arctic Skuas breeding in Iceland provided evidence of a south‐north cline, the light form being more frequent in the north than in the south. In one area there were significantly more dark birds in 1971 than 30 years earlier, but in two other areas there was no evidence of a change in frequency. In northeast Iceland, where the light form is common, there was a statistical tendency towards unlike matings. It is suggested that the adaptive significance of the forms is to be sought in terms of facilitating departures from random mating, the genetic consequences of which are understood in general terms, although the ecological significance remains obscur

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02625.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.Variables of nest architecture and construction behaviour of 62 species of ploceine finches studied by Crook (1963) were reanalysed using multivariate statistical techniques. Phenetic assessments were based on 38 two‐state characters for 48 OTUs. Product moment correlation coefficients and average distance coefficients were used as measures of similarity, and species were clustered using the unweighted pair‐group method with arithmetic averages. A three‐dimensional model was constructed of species plotted with respect to the first three principal components extracted from a matrix of correlations among characters. Principal component and factor analytic techniques were employed to determine trends in character variation.The phenetic affinities expressed in the 3‐D model and two phenograms show many similarities to the phenetic groupings deduced by Crook. However, there were also some differences in interpretation. Crook's Modes C and D were shown as distinct clusters in my analyses, but Modes A and B did not separate completely. In particular, the globular nest ofP. baglafechtof Mode A, Type IV, grouped with kidney‐shaped nests of species of Mode B, Type Va. The treatment ofP. pelzelni, P. madagascariensis, andP. philippinusin my analysis differed somewhat from Crook's. The resulting cluster ofF. sechellarumandM. malimbicusbrought out some effects of standardising data on resulting interpretations of similarity.Species within the subtypes of Crook usually remained close together, but the affinities between subtypes (and types) often differed between our studies. The results of factor and principal component analyses indicate that the main trends in character variation concern those traits found together in (a)M. rubriceps; (b)A. unicolorandPa. superciliosus; (c) forest birds; and (d) non‐forest birds. These groups also are the main clusters. Differences in Crook's and my results are discussed and some of the advantages of utilising numerical techniques to describe similarity ar

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02626.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.The behavioural interactions among breeding Western Sandpipers (Calidris mauri) are described, and interpreted in terms of their adaptive characteristics.Upon arrival in early spring, males disperse onto territories through mutual antagonism. Territorial advertisement and maintenance is accomplished through display flights low over the ground, which are accompanied by soft buzzy vocalisations. These characteristics of display are related to the fact that this species occurs in dense, localised breeding populations, where longdistance communication is unnecessary.Because densities are high and feeding often occurs in communal areas off territory, violations of territorial boundaries are frequent. The result is an extremely high intensity of interactions among individuals. Chasing and physical combat between males is frequent and generally un‐stereotyped. Birds nesting on territories away from the feeding sites often fly high above the other territories, and in doing so avoid being chased.Western Sandpipers form monogamous pair‐bonds which are maintained until the young are ready to fly. The initial association of the pair is facilitated by a strong tendency to return to the previous site and by the advertisement of the males in which a specific vocalisation is given. Once the female is present on a male's territory, she is courted persistently by him and gradually begins to participate in his scraping displays. Pair‐bonds are re‐enforced by the close association of the pair during the pre‐nesting period and through a simultaneous preening display.An hypothesis is developed that the participation of both sexes in incubation serves primarily as a means of pair‐bond maintenance, acting to keep both parents present until after the young hatch. At this time, their presence is needed to provide protection for the precocial young agains

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02627.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.An account is given of nest‐building by captive Quaker ParrotsMyiopsitta monachus.Nests were made by thatching movements, twigs being inserted into a base by a sideways movement of the head. A downward slanting sheaf was formed around an internal cavity. The lip of the nest‐hollow was formed by pulling up and inserting the ends of some twigs. The cavity was shaped by chewing off projecting ends, and floored with chewed and shredded tw

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02628.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02629.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1973.tb02630.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY