bluuebunny/crossref_metadata_2025_split huggingface dataset:
SOCIAL BEHAVIOUR IN THE PARTRIDGE PERDIX PERDIX
Authors: Jenkins David 
Published: April 2008

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 winters.
THE BLACK NODDYANOUS TENUIROSTRISON ASCENSION ISLAND PART 1. GENERAL BIOLOGY
Authors: Ashmole N. P. 
Published: April 2008

SUMMARYSeveral colonies of Black Noddies Anous tenuirostris on Boatswain Bird Island, off Ascension, were studied for almost a year, including the whole of one breeding period and the start of another. Between the breeding periods the noddies roosted on their ledges in the breeding colonies, so observations could be made throughout the year. The single eggs were laid on small ledges, usually on steep cliffs; nest material was scarce, and some eggs fell off the ledges during incubation, but many young were reared successfully in the first part of the breeding period. However, food shortage resulted in slow growth and eventual death of all the chicks hatched later in the season, and the weights of adults were also low at this time.It was shown that individual noddies sometimes bred at intervals of much less than a year, and that breeding occurs in different months in different years; however, the interval between the start of breeding in 1958 and 1959 was almost a year, and i, t is suggested that this was unusual, and a result of the food shortage late in 1958.The moult of the noddies was studied in detail; it was found that individuals were either involved in breeding activities, or were in process of moult, almost all the time, while a few birds started breeding well before they had finished their moult.The discussion concerns the reason for the rough synchrony in breeding among the Black Noddies on Ascension, and the relation between breeding and moult cycles in the population.
THE NEST‐BUILDING BEHAVIOUR OF THE MAGPIE GOOSE ANSERANAS SEMIPALMATA
Authors: Davies S. J. J. F. 
Published: April 2008

SUMMARYMagpie Geese Anseranas semipalmata build substantial nests of vegetation in the extensive Eleocharis/Oryza swamps of Northern Australia. Building activity begins some two months before the eggs are laid, and a large number of stages and preliminary nests are built before the true nest. It is thought that males generally initiate and take a large share in nest‐building. Experimental evidence suggests that building activity is greatly intensified in wet weather.Field observations show that the nests are always placed in swamps, the vegetation of which lies within a specific range of height and density. Experimental work with captive birds is described and analyzed, and suggests that such precise habitat selection results from the behavioural integration of two orientation components. One is an innate tendency to build with up‐and‐down elements in the environment. The other tendency, acquired only after experience, is to build with those elements of the environment that have certain characteristics of height and density. The learning process involved in the acquisition of the latter tendency is thought to be reinforced by the rapid completion of a satisfactory stage.
QUANTITATIVE STUDY OF MIGRATION WITH 23‐CENTIMETRE RADAR*
Authors: Nisbet I. C. T. 
Published: April 2008

SummaryA quantitative study was made of the displays of “angels” on the screen of a 23‐centimetre radar installation on Cape Cod, Massachusetts. The birds responsible for the displays were nocturnal migrants, mainly passerines.Other things being equal, the density of angels decreased roughly exponentially with distance from the centre of the radar screen, being halved about every eight miles. The rate of decrease varied only slightly with total migration density, and could be used to estimate the total number of bird targets in the air.Estimates obtained by this means were compared with estimates of migration density obtained from “moon‐watching” observations, which were reduced by a new method of calculation which incorporates radar measurements of the height of flight. Each angel was found to correspond to between two and twelve birds. After considering and rejecting other explanations, it is concluded that many birds migrate in groups at night. There is evidence that many species (including Parulidae, Turdidae and Emberizidae) migrate in small groups, rather than a few species in large groups. Groups of passerine night‐migrants are probably spread over a wide area, since it is rare to see two birds cross the moon together.Once the average group‐size has been determined in this way, radar can be used to measure the density of migration over a large area. Estimates of low migration density have a standard error about 25%, but estimates of high migration density are less accurate, and very high migration densities cannot be measured at all, although they can be accurately identified as such.The results in this paper cannot be applied directly to other radar stations, nor to other species of birds.
THE FOOD AND FEEDING HABITS OF TUFTED DUCK AYTHYA FULIGULA
Authors: Olney P. J. S. 
Published: April 2008

Summary.The food and feeding habits of Tufted Duck Aythya fuligula are described, based on field observations and on the analyses of the stomach contents of 95 birds, all but one of them having fed inland; 57 were collected from a gravel pit near London, 28 from Northern Ireland and 9 from a number of English inland waters, in the shooting seasons 1959‐60 and 1960‐61.The London birds in both seasons had fed primarily on molluscs, mainly Dreissena polymorpha. The Northern Ireland birds, where D. polymorpha does not occur, had a more variable diet, again mainly molluscs, but with some crustaceans, insects and plant seeds. The English birds had a similarly variable diet with the emphasis on crustaceans (Asellus spp.) and with some molluscs, insects and plant seeds. Brief information is given on the food of young birds.It is suggested that the spread of D. polymorpha may be one of the factors explaining the recent spread of the Tufted Duck in certain areas. It appears that where one particular food such as D. polymorpha is not plentiful a more variable diet is taken, though molluscs always figure prominently. The type of food taken depends on the type of habitat used, the availability and size of the food items and on the methods of feeding.
OBSERVATIONS ON WINTERING BIRDS AND SPRING MIGRANTS IN TRIPOLITANIA
Authors: WatersR.A.M.C. W. E. 
Published: April 2008

Summary.Between 30 November 1960 and 19 April 1961 observations were made on wintering birds and the spring migration in Tripolitania. The main additions and differences from Guichard's (1956‐57) observations are recorded here and a full systematic list is deposited at the Edward Grey Institute, Oxford.
FIELD NOTES ON THE BIRDS OF KOREA
Authors: Macfarlane A. M. 
Published: April 2008

Summary.Notes are given on 78 species of bird recorded in Korea between 7 July 1953 and 14 October 1954, including Temminck's Stint Calidris temminckii and Fantail Warbler Cisticola juncoides apparently recorded for the first time. A further 67 species were also seen.
LIFE HISTORY OF THE RUFOUS‐TAILED JACAMAR GALBULA RUFICAUDA IN COSTA RICA
Authors: Skutch Alexander F. 
Published: April 2008

Summary.In Costa Rica, the Rufous‐tailed Jacamar inhabits both humid second‐growth and primary rain forest, from sea level up to about 3,000 feet. It subsists upon insects, including many large butterflies and dragonflies as well as numerous glittering beetles, all of which it catches on the wing.The search for nest‐sites begins in the dry month of February; eggs are laid from late March until June; and the latest young fledge in July. Both sexes dig the nest burrow in a roadside bank, side of a gully, or the vertical wall of clay raised up by a great uprooted tree. At this time the male often feeds his mate. Burrows range from about 12 to 16 inches in length, are straight or curve more or less to the right, and dilate at the inner end to form a low, unlined nest chamber. The same burrow may be used in successive years.About ten days elapse between the completion of a burrow and the start of laying. The pure white eggs are deposited at intervals of two or more days. In Costa Rica sets of two or three are laid, but farther north in Guatemala two sets of four were found.The female incubates each night. The male replaces her before sunrise, and throughout the day they change places at intervals of 1 1/2 to 2 hours, sometimes more. The incubation period is 19–23 days.The nestlings hatch with abundant, long, white down. They are prognathous and have well‐developed heel pads. They are very loquacious, calling from an early age and soon delivering beautiful, long trills much like those of the adults. Both parents bring them insects, one at a time; no other food was noticed. The male parent fed feathered nestlings about 2 1/2 times as often as the female. In 25 hours, two nestlings were fed at the average rate of 2·4 times each per hour, but there were great hourly fluctuations. Two young who remained in the nest unusually long finally left spontaneously, without parental urging. The nestling period varies from 20 to 26 days and is longest for late broods.Jacamars wholly neglect the sanitation of their nests. They fail to give threat or distraction displays when a man or a small native mammal approaches their burrow.
THE FAIRY TERN GYGIS ALBA ON ASCENSION ISLAND
Authors: Dorward D. F. 
Published: April 2008

SUMMARYThe Fairy Tern was found to have an annual breeding season at Ascension, laying about January. Individual pairs laid on the same ledge in successive seasons with an interval of close to a year. The growth of the chick was variable and slow, a characteristic shared by other Ascension species. The breeding success was higher than in other species of the area, being about 30% in two seasons. The moult was found to be somewhat irregular and, on the available data, puzzling, an unusual feature by comparison with the other local terns. Food and feeding methods are described; pelagic fish of many species were taken. Some observations on behaviour, and some adaptations to cliff‐nesting (particularly anti‐predator responses, in spite of an absence of predators at Ascension), are discussed.
THE TROPICAL FOREST EDGE AVIFAUNA OF IBADAN, NIGERIA
Authors: Elgood J. H. , Sibley F. C. 
Published: April 2008

SummaryThe main types of habitat to be found in the Ibadan area are briefly described and their interrelationships considered. The relative degree of shade and cover afforded by each is discussed in relation to human influences.The avifauna, comprising 266 species so far identified in the area, is classified as comprising forest, savanna, widespread and aquatic forms. The status and frequency of each species is indicated.It is shown that the terrestrial element in the Ibadan avifauna is very evenly balanced between forest and savanna forms.The ability of forest forms to emerge from the forest and occupy less shaded habitats is contrasted with the converse ability of savanna forms to enter forested habitats.A number of species are separately noted in a supplement to Appendix 1 that show points of interest concerning their taxonomy, status or range.
BILL‐CLAPPERING DISPLAY IN THE COMMON HERON ARDEA CINEREA
Authors: Hudson M. J. 
Published: April 2008

SUMMARYBill‐clappering is shown to be a normal feature of the early phases of the breeding cycle in the Common Heron Ardea cinerea and the circumstances of its occurrence are described.Possible origins of this behaviour and its probable function are suggested.An attempt is made to show the development of Ciconiiform display from the integration of more simple patterns. The significance of bill‐clappering in the Common Heron appears to lie in the fact that it suggests an ancestral type of behaviour from which the complex display of the White Stork has evolved.
A BREEDING BIRD CENSUS AND NESTING SUCCESS IN CENTRAL AMERICA
Authors: Skutch Alexander F. 
Published: April 2008

SUMMARYIn a park‐like area of 3.75 acres adjoining primary forest in Costa Rica, at an altitude of 2,500 ft., 83 nests, made by about 49 pairs of birds and two single females, were found in one year. Over a period of 20 years, 64 species were recorded as nesting in this same area.The difficulties of learning the actual rate of success of nesting birds are discussed, and it is concluded that, in view of the impossibility of assessing the effects of visits of inspection to nests in natural habitats, statements of breeding success are at best rough approximations of what happens in the absence of an observer.In the area of the census, nest‐success (the proportion of nests in which at least one egg was laid that produced at least one living fledgling) was 38–53% in four different years. During the four years 41 % of 208 nests were successful.Of 756 nests of 23 species of altricial birds of the Central American lowlands that build open or roofed nests in clearings and second‐growth, 37% were successful. When the computation is restricted to nests found before the last egg was laid (class B nests), 35% of 434 nests were successful, and 30% of 883 eggs produced living fledglings.In the neighbouring forests, nesting success was much lower, only 23.5% of 136 open or roofed nests producing at least one fledgling. Many forest birds increase their chances of success by entering neighbouring clearings to breed, but few open‐country birds build their nests in the forest.In both forest and clearings, hole‐nesting birds in Central America are much more successful than open‐nesters, as has been found also in the North Temperate Zone.A comparison of the results of a single season's observations in each of six Central American localities shows an increase of nesting success with altitude. In lowland Panama, the nest‐success was only 21%, in the Subtropical Zone of Costa Rica 53%, and in the altitudinal Temperate Zone of Guatemala 55%. The effect of altitude is complicated by differences in the amount of forest in the localities chosen for study, as well as by other factors difficult to assess.In both the tropics and the North Temperate Zone, nest losses are substantially higher in woodland than in man‐made habitats, evidently because there are fewer predators in the latter; but, even in clearings in Central America, nesting success was considerably lower than it was found to be in numerous studies in the North Temperate Zone. The difference may, however, reflect the greater “wildness” of the localities where the writer's studies were made, rather than a true contrast between tropical and temperate zone conditions.Snakes appear to be of the greatest single cause of nest losses in tropical America, but mammals, a few predatory birds, ants, and possibly even bats, destroy many eggs and young.Since small broods and heavy predation permit only a small annual contribution to the adult population, it is evident that, in order to maintain the species, adults must enjoy fairly long lives. Recent statistical studies support this theoretical conclusion.
SEASONAL VARIATION IN THE FOOD OF THE PURPLE MARTIN PROGNE SUBIS IN KANSAS
Authors: Johnston Richard F. 
Published: April 2008

SummaryStomach contents of 34 Purple Martins Progne subis and 90 netted samples of flying insects were analysed taxonomically and quantitatively and compared with one another. Insect food sources tend to become more abundant, taxonomically variable, and larger in size late in the season (August). Maximal availability of food thus coincides with maximal energy requirements of Purple. Martins, which then are at peak numbers, initiating moult, accumulating fat and beginning migration.
NOTES ON SOME MARSH BIRDS OF CAPE SAN ANTONIO, ARGENTINA*
Authors: Weller Milton W. 
Published: April 2008

SummaryDuring an 11‐month study of the Black‐headed Duck in eastern Argentina, observations were made on the marsh birds of Cape San Antonio, Province of Buenos Aires. These observations supplement the distributional and life history obtained by Gibson (1879–1920), Wetmore (1926) and others.The deep, fresh‐water marshes characteristically are dominated by one of three plants: tules, cutgrass or cat‐tails. There were surprisingly few marshes with mixtures of these plants and few marshes which showed a gradual transition from marsh to uplands.Marsh birds showed considerable adaptation in chronology of nesting and nest‐site selection for the seasonal water cycle of wet springs and dry periods in the late summer and fall. Some marsh birds were involved in nesting over a longer period than is usual in Northern Hemisphere marshes. As seems characteristic of all marsh birds, cover‐water edges were usual sites for nests. There were only a few species with restricted nest‐site selection, and competition between closely related species was noted only among the three species of coots.A list of the marsh birds of the area is given, and comments are presented on the ecology and behaviour of selected species.
STUDIES OF THE DIEDERIK CUCKOO CHRYSOCOCCYX CAPRIUS IN THE TRANSVAAL
Authors: Reed R. A. 
Published: April 2008

SummaryThe migrant Diederik Cuckoo Chrysococcyx caprius was studied on a 72–acre area near the Klein Jukskei River near Johannesburg from 1955–1958. The birds first arrive in early October, after which the males take up territories and call continually until February; subsequent calls up to April are probably made by young birds.Courtship displays, which involve courtship feeding, and egg‐laying follow the birds' arrival by about a month. The Red Bishop Euplectes orix was the species most commonly parasitized, with smaller equal numbers of Cape Sparrows Passer melanurus and Masked Weavers Ploceus velatus. The cuckoos' eggs differ according to the host species and in two cases hatched between ten and 14 days after laying. The chicks normally evict their hosts' offspring on the second or third day after hatching. The fledging period appears to be roughly 19–20 days, and there is a period of post‐fledging care lasting between 17 and 38 days, during which the chicks are fed different foods by different host species (grass seeds by bishops; insects of different sizes by weavers and sparrows).The fact that the eggs and the calls of the chicks vary according to their host species suggest the existence of three separate host‐specific strains in this area. The incidence of brood parasitism in Red Bishops' nests varied from 7–50% and averaged 25%.
THE RECOGNITION AND TREATMENT OF VENOMOUS AND NON‐VENOMOUS INSECTS BY SMALL BEE‐EATERS
Authors: Fry C. H. 
Published: April 2008

SummaryThe manner in which bee‐eaters cope with the stinging honey‐bees which comprise their principal food was investigated by aviary studies of Merops bullocki. Worker Apis are de‐venomed by an innate sequence of beating the insect and rubbing its abdomen against the perch. Treatment improves with experience. Drone bees are distinguished by the birds from workers but are not instantly recognised as non‐venomous; they are subjected to low intensity rubbing combined with non‐venomous prey treatment concomitant with their size. Non‐Hymenoptera, including some insects which superficially resemble bees, are recognised as non‐venomous and are not rubbed, but are beaten until immobilized. Bee‐eaters appear to have partial immunity to venom.
FULMAR DISTRIBUTION: A CANADIAN PERSPECTIVE
Authors: Brown R. G. B. 
Published: April 2008

SummaryThe pelagic distribution of the FulmarFulmarus glacialisoff eastern Canada has been used to test Fisher's (1952, 1966) hypothesis that Fulmar numbers are controlled by the availability of offal from the fishing industry. Fulmars are abundant on the fishing Banks off Newfoundland but not on those off Nova Scotia; by contrast, they are fairly common in the unfished waters south of Greenland. The Newfoundland and Greenland waters are colder than those off Nova Scotia, and it seems likely that temperature and other oceanographic factors, not fish offal, control Fulmar distribution in the western Atlantic. Since the ringing returns show that many of these Canadian birds are from British colonies, it is possible that fish offal may not be the key factor in the eastern Atlantic either.Since there are no reliable quantitative data on the Fulmar's diet, it is difficult to suggest a specific alternative. However, the Fulmar is, over much of its range, a cold‐water species; it may eventually be possible to interpret Fulmar distribution in oceanographic terms, the key factor being its macroplanktonic food. However, the Fulmar population in the warmer waters of the eastern Atlantic remains an anomaly; it is not yet possible to explain the differences in ecology between the eastern and western Atlantic birds, either in oceanographic terms, or by the availability of fish offal.