摘要:

SUMMARY1 This paper describes a five‐year study in the pine plantations of Thetford Chase, East Anglia, to test the hypothesis that populations of tits (Paridae) and GoldcrestsRegulus regulusare controlled by food shortage; and secondarily to assess the impact of bird predation on populations of forest insects.2 In winter, tits spend most of the day feeding; each bird examines some 1100 trees daily, and must find about 5 mg. dry weight of food, or 24 average‐sized insects, every minute of the day to maintain itself. Coal TitsParus aterand Willow TitsP. montanusstored much food in spring and autumn; but stored foods formed a very small part of their diet. Interspecific segregation among the feeding birds was less marked than among the same species in broad‐leaved woods.3 The stock of invertebrate food in the pine foliage in winter ranged from 15–500 mg. dry weight per m2of forest. The stock declined steeply during the winter, but increased again slightly in early spring. The level to which it fell in late winter was closely correlated with the mean air temperature at the time.4 In winter, the birds sometimes ate a substantial proportion of the available stock of food; in particular, they regularly ate about 50% of the stock of the eucosmidErnarmonia conicolana(Heyl.), which was an important food of Blue Tits (Gibb 1958). The birds probably ate similar proportions of other suitable foods. Intraspecific competition for food was judged to be often severe.5 In winter, the birds' density was closely related to their stock of food. Coal Tits' survival from the end of the breeding season to the end of September was nearly constant from year to year, and was not correlated with the stock of food; but their survival from October to March was extremely variable and was closely correlated with the stock of food. This confirms that the population of tits was controlled by food shortage; nevertheless their territorial behaviour in autumn was probably also important.6 The paper ends with a discussion on the impact of bird predation on forest insects. It is concluded that as the birds eat a substantial proportion of the invertebrate stock in winter, they are at least a force to be reckoned with; also, if they help to stablise forest insect populations stepi should be taken to increase their numbers, perhaps most profitably by planting a variety of tree species to provide them with add

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07112.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

SUMMARY1. Bramhlings of both sexes, including young males, failed to show significant gonad enlargement or to develop springZugunruheduring the normal migratory period while artificially kept under winter day‐lengths.2. When the photoperiod was suddenly changed to 14 1/2 hours (equalling mid‐April day‐lengths) nocturnal unrest became apparent in all birds within three days, even though the normal migratory period was now past.3. This temperate‐zone, spring‐breeding migrant therefore does not come rhythmically into breeding condition as do the young of the xerophilous Budgerygah and Zebra Finch.4. Concurrently with light‐inducedZugunruhethere occurred a striking fat deposition and, in the adult males, a minor gonad enlargement. A separate experiment involving the photo‐stimulation of castrated adults tends to suggest thatZugunruhe(and therefore possibly migration) can occur in the absence of sex hormones but the regeneration of a single gonad in one of the castrates rendered the results

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07113.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

SUMMARYThe electrophcrctic profiles of the egg‐white proteins of 359 species of non‐passerines and at least 300 species of passerines have been studied. This paper is concerned primarily with the non‐passerines.Protein structure is genetically determined and tends to be phylogenetically more conservative than most other characters used in taxonomy. The electrophoretic profiles provide an index to some aspects of protein structure and hence to phylogenetic relationships. The present technique is described and his been found to be most informative at the generic, familial and ordinal levels. Individual variation, variation among morphological “breeds” of Domestic Fowl, and variation within species, genera, families and orders have been taken into account in the comparisons.The principal conclusions are as follows:1. The Struthioniformes and Casuariiformes arc probably related but the relationships of these to the Rheiformes are uncertain.2. The Tinamiformes do not seem to be related to the Rheiformes or to the Galliformes.3. The Pelecaniformes may be polyphyletic but this is uncertain.4. The three available species ofSulahave remarkably different egg‐white profiles. The significance of these differences is not known.5.AnhingaandPhalacrocoraxare closely related and may be included in the same subfamily.6. The Flamingos are related to the Ciconiiformes, not to the Anseriformes.7. The Gaviiformes seem to be more closely related to the Charadriiformes than to any other group.8. The Aramiclae are closer to the Rallidae than to the Gruidae.9. The Gruiformes are probably polyphyletic. There is no evidence thatEurypygaorPsophiaare closely related to the Gruidae, the Rallidae or each other.10. The Gallrormes (Opisthocomusnot studied) are a very close‐knit monophyletic group. The order is divided into three families, Megapodiidac, Phasianidae, Opisthocomidae. As subfamilies of tht Phasianidae: Phasianinae, Meleagridinae, Numidinae, Tetraoninae, Cracinae.11. The Anat dae are also monophyletic and closely related.Anseranasseems sufficiently distinctive to be placed in a monotypic tribe or possibly given subfamily status.12. The Falconiformes‐ may be polyphyletic, the Falconidae possibly being unrelated to the other diurnal birds of prey. The Cathartidae are related to the Accipitridae.13. The Strigiformes and Caprimulgiformes are related.14. Turacos (Musophagidae) are cuculiform, apparently related to the Cuculidae throughCentropus.15.Merops, Momotusand the Alcedinidae are related to one another but seem unrelated toEurystomus(Coraciidae). The Coraciiformes are therefore probably polyphyletic.16. The genusColumbais probably polyphyletic, the Old World species being distinct from the New World species.17. The Coliilormes and Trogoniformes are each distinctive and have no close relatives. Both may be related to the Passeriformes.18. The swifts and hummingbirds are related to one another and possibly to the Passeriformes.19. A request for help in obtaining additional material is made and instructions for collection and shi

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07114.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

摘要:

SUMMARY1. The African Fish EagleHaliaetus vociferis discussed, with especial reference to the Kavirondo Gulf area of Lake Victoria.2. Numbers in I his and adjacent areas are given, and reference is made to possible movements on Lake Victoria.3. Territories and home ranges of seven pairs breeding on a group of islands overlap somewhat, with a tendency towards mutual stimulation by adjacent pairs, and the possibility of breeding and hunting difficulties through overcrowding.4. Some pairs appear to be permanently resident in certain areas without breeding at all.5. The data on food indicate that the African Fish Kagle eats more birds than has generally been supposed, especially Hamingos; the diet may be summed up as fish when abundant, otherwise water‐birds and some carrion.6. The breeding cycle is discussed under the heads Display, Nests and Nest‐building, Eggs and Incubation, the Fledging period, and the Post‐Hedging period.7. Breeding seasons, and their possible relations to food supplies and climate are discussed.8. Three years' data on breeding success indicate a mean annual replacement rate in the Kavirondo Gulf of 0–6 young per pair per annum, with wide variations in the performance of individua

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07115.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07116.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07117.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07118.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07119.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07120.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1960.tb07121.x

出版商:Blackwell Publishing Ltd    

年代:1960

数据来源: WILEY