摘要:

Summary.Based on work during residence from January 1950 to October 1952, a revised check‐list is presented for the Tristan Group, together with field and taxonomic notes on the individual species. Only two subspecies of birds, other forms of which survive elsewhere in the group, are known to have become extinct during the century and a half of human settlemen

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb03049.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.1. The species‐composition, number of individuals and biomass per one‐hectare are given. The three groups of areas studied were: (1) bare pastures, with an intermediate number of bird species, few individuals and high biomass of mainly carnivorous and insectivorous birds; (2) conifer plantations 1 to 5 years old, with the smallest number of bird species and the smallest biomass, but an intermediate number of individuals; (3) plantations six to twenty years old, with the highest number of both species and individuals of birds, but only intermediate biomass.2. The change from pasture to forest occurs about six to ten years after planting. The last forest birds come in about 20 years after planting.3. Birds have an important role in establishing the shrub layer and mixing some tree‐species into the plantation, by dissemination.4. Throughout the entire successional series the bird population seems to have a kernel of species, while other species come or go and/or change in density with the s

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb03050.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.Field notes are given on birds living in a peculiar habitat of the Peruvian high plateaux, the Puya stands, studied in Southern Peru, near Azangaro, north of Lake Titicaca. These plants provide roost‐sites, feeding‐places and especially nest‐sites for the various species listed, but the sharp hooks on the leaves also cause the death of many birds, ranging from small passerines to Sparrow Hawks and Buzzards.A distraction display by the Black‐winged Spine‐tail is

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb03051.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.1. The Huleh swamp and lake, which are now under a draining scheme, are described in relation to their vegetation habitats and the birds breeding in them.2. Data are presented on the breeding birds, concerning their distribution within Israel, laying season, nest site and clutch size.3. The Common Heron, White‐tailed Eagle, Marsh Harrier, Mallard, Baillon's Crake, Yellow Wagtail, Moustached Warbler and the Great Reed Warbler are here first recorded as breeding in Israel.4. The relationship betweenAcrocephalus arundinaceusandA. stentoreusis discussed.5. Some remarks are made on habitat selection of the warblers breeding in the are

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb03052.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.The literature on the food ofGypohieraxis reviewed. First‐hand evidence of the bird's catching live fish in the Gambia is cited. Up‐to‐date information is given about the ecology of the bird in East Africa, with particular reference to its occurrence in the absence of oil‐palms and its eating Raffia fruit. On the basis of this and of the survival ofGypohieraxin zoos, it is concluded that the vitamin‐rich oil‐palm fruit is not essential to the bird; but one that had been in captivity for 11 years, when presented with the fruit, preferred that to its

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb03053.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.A reliable method is described for preparing a complete cast of the pulmonary system of birds in transparent synthetic resin. A cast of the bronchial tree can be isolated by trimming away the casts of the air sacs and parabronchi. Only simple and inexpensive apparatus is required.

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb03054.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.1. Of 17 adult males of nine species of southbound migrants that were accidentally killed at about the point of departure from Southern Britain in autumn, all possessed an interetitium in the process of post‐nuptial rehabilitation (involving cholesterol production) even though they were flying away from the traditional breeding ground. Varying amounts of cholesterol‐positive material still lingered in the tubules.2. Of 11 juvenile males of seven species similarly collected only six individuals possessed an interatitium in which had already developed cholesterol. One adult Redwing showed pronounced signs of autumnal sexuality in the production of a few primary spermatocytes.3. Cholesterol is almost certainly the precursor of the steroid hormones; and its early conversion into androgens in “stationary” species is probably responsible for the widespread autumnal sexual behaviour that occasionally culminates in “out‐of‐season” reproduction. Its presence in adult migrants probably explains the recrudescence in sexual behaviour that occurs in certain species just before their departure from the breeding grounds. In migrants, however, unlike “stationary” species, this capacity to display is extinguished by the more powerful (in them) inherent urge to migrate.4. Southbound, as well as northbound, migrants possess subcutaneous and subperitoneal fat‐deposits. The physiological basis for the production of this material is discussed briefly, and a possible additional function for

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1957.tb03055.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.tb03056.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.tb03058.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.tb03059.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY