摘要:

Summary1. Some aspects of Partridge behaviour (see Contents) are described, and, using defined criteria, activities are divided into: (a) those resulting primarily from intraspecific interaction (agonistic behaviour); (6) those occurring independently of interaction, mainly feeding and courting. Some activities, notably preening and resting, were found to occur under both heads, and were classified with group (a) because they were thought sometimes to be displacement activities. An index is described to measure the proportion of time spent feeding and courting, and hence, inversely, the amount of interaction, under different circumstances. The behaviour of birds in different environments is compared.2. It is possible to correlate the degree of interaction with population density and ground cover in different fields. There was less interaction when the birds were living at low density, or where the ground cover prevented them seeing each other. In good cover, and also in low–density areas, the size of home ranges was relatively small and they did not overlap; in areas where density was high and ground cover poor, home ranges were larger and overlapped. Birds in good cover interacted little with each other, even at a high population density; but others, living at similar population densities, interacted continuously if the cover was poor. Intermediate situations are also described.3. The possible importance of agonistic behaviour with regard to dispersion and population control is discussed briefly.4. A correlation was observed between chick mortality in two summers and the interaction observed among adults during the previous winter

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02431.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary1.Zugunruhe,a condition of nocturnal activity in caged migratory birds that is generally held to be identical to premigratory restlessness in the wild, developed in the spring in captive castrated male BramblingsFringilla montifringilla.2.Zugunruheoccurred in intact control birds about a week before it was recorded in castrates. Intact birds became restless each evening earlier than did the castrates.3. Nevertheless, the peaks of intensity in both castrate and intact birds occurred at the same time and coincided with the period during which the bulk of the wild population migrated to their northern breeding grounds.4. In intact birdsZugunruheoccurred during the initial period of seasonal gonad modification. It waned by the time of sperm‐production when, under wild conditions, the birds would have completed their journey to their distant breeding grounds.5. The data suggest that the seasonal phenomena of migratory unrest and gonad development occur independently of each other. The remote possibility that migration is influenced by extra‐testicular androgens is mentio

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02432.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary1. Migration was studied at the Bosphorus from 20 August to 8 September 1959 and observations made at the Dardanelles, on Lesbos, and in parts of Greece.2. Daily counts of soaring birds migrating over the Bosphorus are given. The species involved were principally White StorksCiconia ciconia,Honey BuzzardsPernis apivorus,and Black KitesMilvus migrans.Few eaglesAquilasp. were seen.3. The winds were mostly strong, northeasterly. Heavy migration occurred only when the wind was light. It is considered that migration of soaring birds over the Bosphorus is virtually inhibited by strong N.E. winds; but whether they cross the Sea of Marmara to the south is undecided.4. White Storks were observed migrating over the Sea of Marmara and the pattern of their migration through the area is discussed.5. Both nocturnal and diurnal migrant passerines were recorded in only moderate numbers.6. Large numbers of gulls and terns (Laridae), especially of Little GullsLarus minutus,were seen in the Bosphorus and elsewhere.

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02433.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02434.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

SummaryA strong tendency in non‐migratory Mallard to fly N.W. on release is described. This orientation is shown regardless of distance and direction of release, of season or of length of captivity. It is shown at any time of day by birds of both sexes and of all ages, and is unaffected by the topography of the release site. Head winds of moderate strength impart a wider scatter, otherwise winds have little effect. It appears to be a sun‐compass orientation.The orientation breaks down, probably quite quickly, and is replaced by random wandering. There are no indications of true navigational ability.It is suggested that the orientation may function to keep flocks together and be related to the northward post‐fledging movements of many birds.The existence of such a strong orientation and its presence in another non‐migratory bird, the pigeon, is considered to have caused confusion in experiments on navigation undertaken with the latter. Results obtained with pigeons in N. Carolina and Germany can no longer be considered conclusive. The conflict of their results with those obtained in England is r

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02435.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

SummaryThe sound spectrograph, s an indispensable tool for the fuller objective analysis of animal vocalisation. It is particularly valuable in study of bird song. The sound spectrograms themselves, as produced by the instrument, contain, however, an excess of information which is not always relevant to the comparative study of specific songs. Moreover, the scale and delicate shading of the originals render them needlessly difficult for the field student of bird song to interpret, and needlessly expensive for journals to reproduce. A simplified and graphic notation, consisting of a series of conventional symbols, has been worked out. This, it is believed, largely overcomes these difficulties without the loss of any information essential for the field student.

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02436.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary1. The songs of the Emberizidae are discussed. Recordings of at least one species of 18 of the 21 genera are analysed by means of the sonograph.2. The songs of this family are characteristically short, repetitive and simple, primarily for territorial proclamation and therefore with good specific differences.3. The similarities between the songs of the genera may be accounted for by convergence as many have similar reproductive and nesting habits.4. Many songs are stereotyped, but some show a great deal of variation, which in some cases may provide a means for individual recognition.5. Wheezing and buzzing, duration of song, and the tendency to deliver songs in bursts of one type are considered to be possible generic characters.6. A tendency for a lark‐like quality to be developed is found in those species with a song fligh

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02437.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

SummaryThe ringing of Giant Petrels by F.I.D.S. parties in 1957‐58 and 1958‐59 is reviewed and the presence of a newly discovered rookery below the Antarctic Circle noted.A comparative analysis is made of the numbers of recoveries received and the difference in their distribution amongst the southern continents during 1958 and 1959.Details of 112 recoveries are given in an Appen

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02438.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Summary1. A systematic list of the birds of Annobon Island in the Gulf of Guinea is presented with field notes obtained on a recent expedition, and the records are compared with those of previous ornithological visits.2. The land avifauna of Annobon has altered markedly in the last five or six decades. That the resident land‐birds provide severe competition for newly arrived immigrants is offered as the most plausible reason for the paucity of land‐birds species on the island.3. Brief ornithological notes from Sao Tom and Fernando Po are given as addenda to recent papers on the respective avifau

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02439.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

SummaryThe goslings of the Magpie GooseAnseranas semipalmatamake co‐ordinated pecks about 40 min. after hatching. The intensity of pecking is greater by day than by night and also increases with increasing age in unfed goslings. In a series of experiments goslings tended to orientate their pecks towards high, light, green and yellow objects rather than low, dark, blue or red ones, but did not discriminate between rough and smooth objects. It is suggested that these generalized orientation tendencies suffice to direct the goslings' pecks towards potential food, the seed heads of swamp plants. A more precise innate orientation, such as is found in some gull chicks, would not confer greater protection from predation than the shelter of the breeding swamp itself provides, and might prevent the goslings from exploiting some of the available foo

ISSN:0019-1019    

DOI:10.1111/j.1474-919X.1961.tb02440.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY