ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01931.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.1 Bunting calls in general express the tendencies to fly, to behave sexually, to behave aggressively, or to give fear responses. (Close begging‐calls probably express a tendency to feed.)2 Bunting social calls express weak fear aroused by being alone, and as a result are often given by solitary males before they sing.3 A primitive “seeoo” call expressing fear has probably evolved into (a) a call easy to locate that expresses weak fear and serves as a social call, and (A) a call difficult to locate that expresses strong fear and serves as an alarm‐call.4 The “tit”‐type flight‐call, which both in its normal form and in its probable variant, the distant begging‐call, shares with social calls the function of keeping birds in touch with each other, is also easily located.5 When there are simultaneous tendencies to give two different calls, the form of one may be imposed on the other (e.g.a normally repeated flight‐call may be given singly, or an alarm‐call be rapidly repeated in

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01932.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.This paper consists of a catalogue of all species known to occur in Greece. Indications are given of the status, distribution and relative abundance of all these (except rare vagrants and accidentals), in the north, centre and south of the country, and of the habitat or habitats in which they are generally found. The notes on each species are based on the studies mentioned in the list of references and on personal knowledge of the country gained during three years' residence from 1952–195

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01933.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.A classification of the known methods of incubation of the birds of the world, on the basis of the division of labour between the sexes and the apportionment of time on the eggs, shows that practically every feasible pattern has been adopted by one species or another.A review of the evidence suggests that incubation by both sexes was the primitive method among birds.Among passerines, there appears to be little correlation between incubation by the male and his possession of a brood‐patch. Some males which regularly incubate lack it, whereas others which fail to incubate develop it.There is also poor correlation between the form of the nest (whether open or covered), the coloration of the two sexes, and their participation in incubation.Participation of the sexes is not generally correlated with the environment. The non‐incubation by the female Emperor Penguin and the sharing of incubation by the male Gould's Hummingbird, seem to be instances of response to rigorous climates.Except possibly in migratory birds whose breeding season is short, incubation by the male seems compatible with efficient territorial defence. Some males and even females sing loudly from the nest, apparently without betraying it to predators.When the sex‐ratio is strongly unbalanced, the failure of the less numerous sex to incubate makes it possible for a larger proportion of the adults to reproduce. But in a number of species in which polygamy or polyandry occurs, the sex‐ratio is not known to be unbalanced.Many modifications in the incubation pattern, especially those involving the participation of the sexes, appear to be non‐adaptive, and to persist because they do not decrease reproductive e

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01934.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.1 The Bermudas are a small group of oceanic islets 600 miles from land in the eastern North Atlantic. This paper is an attempt to define the unusual features of the ornithology based upon personal experience from 1940 to 1944 and a review of the literature.2 Many lost migrants visit the group, but the resident community is restricted to roughly twenty species, all of which were once abundant. A hawk and several sea‐and water‐birds were exterminated after the islands were colonized in the seventeenth century; the present community includes reduced numbers of aix sea‐, four water‐, and ten land‐birds, of which four at least were introduced by man and others may be recent arrivals. The Barn OwlTyto albaand the Common TernSterna hirundohave colonized the group since 1930. Several other introductions which were temporarily established have died out.3 The smaller land‐birds are unusually abundant and exploit an unusually wide range of habitats in the absence of competition for food from related species. The numbers of the BluebirdSialia sialisand possibly other species have fallen since the arrival of the House SparrowPasser domesticus.Most birds are unusually tame, and show peculiarities of voice and behaviour; they nest unusually high in trees, and build large exposed nests. There are two good endemic races,Vireo griseus bermudianusandPterodrom

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01935.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.Observations are given on the migrants observed in Tripolitania during the spring of 1955 and the duration of the passage of 35 species is tabulated. The migrants cross the whole of orthern Libya, from the Tunisian to the Egyptian border.

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01936.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01937.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01938.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01939.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb01940.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY