ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07295.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYThe results of a three‐year study of the diet ofQuelea queleain the Lake Chad region of Nigeria indicate why this bird periodically does extensive damage to crops of dry‐season guinea‐corn.The normal food of the birds in the early dry‐season consists of small grass seeds collected off the ground. As the supply of these diminishes there is a gradual change‐over to larger seeds.In years when this change begins early, it is liable to coincide with the ripening of the cereal crop and severe damage may be caused.At the beginning of the rains the dry‐season food supply is lost owing to the simultaneous germination of the seeds over large areas.The birds lay down fat reserves in preparation for this lean period.After a short time the birds migrate south to regions where rain has been falling for some weeks.In the short period spent in these parts, Queleas feed on ripening grass seeds—including those of cultivated millet.There is evidence for considerable mortality during this time of food scarcity and it is suggested that the numbers of Queleas are limited by the food supply.The significance of communal roosting is discussed. It is proposed that the phenomenon is related to food finding, the roost being considered as an “information centre” for the large area prospected by the birds constituting the roosting community. A method is outlined by which information on food availability within the feeding area may feasibly be transmitted wit

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07296.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYBetween November 1955 and May 1956 continuous observations were made on the sea‐birds of Gough Island. These have been augmented by further occasional observations during seven subsequent years, and are compared with all previous published records for the island.A check‐list of 30 species of sea‐birds has been compiled and substantiated, as far as possible, by a series of skins of 20 species.Nearly 900 sea‐birds cf 20 species were caught and measured, considerably more than at any previous time there; in the case of eight species, these are analysed in detail and some are compared with those from other populations.The relative status of each species was estimated, together with total breeding populations where possible. In same cases the distribution of nests was mapped.A detailed sound and photographic record, of 14 and 16 species respectively, was made.Numbers of Wandering AlbatrossesDiomedea exulans dabbenenaand skuasCatharacta skua hamiltoniwere ringed and colour‐marked respectively to enable a more detailed study to be made of them.General observations were made on the nesting seasons, breeding behaviour and moult of various species which are treated syste

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07297.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

SUMMARYA collection of over 1, 900 skins made in Southern British Cameroons 1955–1957 is described. The range of many forms is extended.The field habits of many forms are described and there are observations on the nidification of the following:Francolinus bicalcaratus ogilvie‐grantiColumba arquatrix sjöstedtiCentropus monachus occidentalisApus affinis abessynicusMotacilla clara chapiniIxonotus g. guttatusAndropadus I. latirostrisAlseonax adjustus obscurusErranornis longicauda teresitaTerpsiphone r. rufocinereaTurdus libonyanus saturatusCossypha c. cyanocampterPetrochelidon preussiCinnyricinclus l. leucogasterChalcomitra r. rubescens Cyanomitra oritis bansoensis Gymnoris d. dentata Quelea erythrops Spermestes bicolor poensisThe stomach contents of several hundred specimens are noted and recorded in such general terms as fruit, seeds, or insects.Taxonomy. The following races are regarded as invalid:Streptopelia vinacea savannae, Gymnobucco calvus major, Bradypterus barratti youngi, Anthreptes fraseri cameroonensis.The following controversial races are upheld:Tympanistria tympanistria fraseri, Pedilorhynchus comitatus camerunensis.Megabyas flammulatusis regarded as a species without r

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07298.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07299.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07300.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07301.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07302.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07303.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1965.tb07304.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY