摘要:

SummaryA survey was carried out on the prevalence of blood parasites in birds in the Mascarene Islands. Smears from 357 birds of 25 species in 12 families were examined, of which 150 (42%) were found to harbour blood parasites. The most common parasites wereLeucocytozoon; a new species,L. zosteropis, is described from the Grey White‐eyeZosterops borbonica mauritiana.This parasite was observed in smears from 68 birds of three species:Z. borbonica, Z. chloronothosandZ. olivacea.Other species ofLeucocytozoonidentified wereL. fringillinarumfrom fodies, sparrows and a bulbul andL. marchouxifrom two doves.Haemoproteuswas found only in domestic pigeonsColumba liviaand identified asH. columbae. Plasmodium relictum, P. vaughaniand an unidentified species with elongate gametocytes were found inZosterops, andPlasmodiumsp. of low infection observed in other hosts.Trypanosoma mayaeis redescribed from the House SparrowPasser domesticusand the Mauritius FodyFoudia rubra, and considered to be a valid species. A new species of trypanosome,Trypanosoma phedinae, is described from the Malagasy SwallowPhedina b. borbonica.Other birds were found to harbour low infections of unidentified species of trypanosomes. A small number of birds were infected withAtoxoplasma, haemogregarines and Rickettsia‐like organisms. An unidentified organism with a predilection for eosinophils was observed in several Mascarene SwiftletsCollocalia francica.The results are discussed in relation to the possible effects of the parasites on the birds of the Mascarene Islands and comparisons made with the results of similar surveys on other Indian Ocean Isla

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02053.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SummaryThe presence of 191 species, regarded as forest birds, was sought in ten forest reserves of south‐west Nigeria. One of these reserves, Gambari, some 25 miles south of Ibadan, was visited 60 times and the species encountered each visit were noted. From these two series of data estimates of the dispersal and commonness of each species have been made, though not all the 191 species were met during the study.A comparison has been made between the forest birds of southwest Nigeria with those of southeast Nigeria as recorded by Serle (1957).The occurrence ofApalis nigricepsat Sapoba in Mid‐western State and ofParmoptila woodhouseinear Lagos are noted as showing a considerable westward extension of their formerly known ran

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02054.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SummaryMixed‐species flocks of birds were observed between the end of July and late August, principally at Daksum, Kashmir, 2250 m. The species composition and the numbers of individuals in flocks changed during this period; these changes are attributed to resident territory holders and migrant birds joining the flocks. Within the flock different species showed some differences in foraging stations, but nevertheless often appeared to be taking the same type of food. Participant species had different roles in the flock organization. Behaviours involving the entire mixed‐flock acting as a unit included path reversal after encounters with avian predators and a tendency to follow set routes. The mixed‐ species flock exerted an attractive influence on aggregations of species not normally participant.Similarities between the flocks described in this study and those recorded by other workers are discussed. While different species may derive different benefits from joining these flocks, advantages that could benefit some or all participants include the receipt of information on good feeding areas in an unfamiliar locality, the avoidance of time wasted on feeding on substrates which have been very recently harvested, the beating effect to increase prey availability, and enhanced safety from predators, perhaps through differential alertness of different species and specialized anti‐predator be

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02055.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

摘要:

SummaryThe body‐weights of OystercatchersHaematopus ostraleguswintering in Morecambe Bay, north‐west England, showed marked seasonal changes between late summer and late winter, with considerable differences apparent between adult and immature birds. An attempt is made to relate these changes to recorded seasonal variations in prey biomass and to the annual cycles of breeding, moult and migration of the Oystercatcher.The mean weight of females invariably exceeded the mean weight of males in samples collected on the same dates, regardless of age. Adults returned from northern breeding areas in very lean condition, with mean weights ranging from 526 g in males to 540 g in females. Mean weight then increased progressively, due mainly to fat deposition, to a peak in March (up to 662 g in males and 675 g in females) around the time of their main departures for breeding. Heaviest birds then exceeded 800 g. Birds migrating to Iceland in spring would need to be of above average weight in March to make the shortest crossing (850 km, 13 h), via Scotland, while Oystercatchers of 700 g and over could probably make a direct flight (1500 km, 25 h) from Morecambe Bay in favourable weather. Breeding weights of British Oystercatchers were similar to those of post‐breeders returning to Morecambe Bay in late August.The mean weights of first‐year Oystercatchers arriving in August were very low, 449 g in males and 478 g in females. Their weights, and those of second‐ and third‐year immatures, then rose rapidly in autumn, with some fat deposition, and reached mean values ranging between 551 g (males) and 597 g (females) by November‐December. Mean weight then fell by 10–17% from December to March returning close to or below the September levels, whereas adults gained a further 6% during these winter months.Summer and autumn weight gains, and the major moult of adults and older immatures, occurred when the biomass of their two staple mollusc preys,Mytilus edulis(mussel) andCardium edule(cockle), was maximal. Winter loss in mean weight of immatures corresponded with declining prey biomass, suggesting either that they were less efficient than adults in coping with deteriorating winter food supplies, or that they had no need to accumulate further (premigratory) fat reserves. The autumnal increases in mean weight of immatures are interpreted as an adaptation for withstanding adverse feeding conditions in winter.The Oystercatcher appears to be the only wader species in Britain in which adults increase, rather than lose, weight during the winter. This may be a consequence of an early breeding season, but it may be regarded also as a measure of the success Oystercatchers have achieved by specializing on a difficult but plenti

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02056.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02057.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02058.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02059.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02060.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02061.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1977.tb02062.x

出版商:Blackwell Publishing Ltd    

年代:1977

数据来源: WILEY