bluuebunny/crossref_metadata_2025_split huggingface dataset:
TEMPERATURE RHYTHMS IN AFRICAN MONTANE SUNBIRDS
Authors: Cheke R. A. 
Published: April 2008

SUMMARYThe thermoregulation of Nectarinia tacazze, N. famosa, N. mediocris and Anthreptes collaris was studied at three localities in the Cherangani mountains, Kenya. Most of the experiments were conducted at an altitude of 3,350 m.These sunbirds were found to have a diel temperature rhythm with ranges of 5o‐17oC, an adaptation for survival in the severe temperature regimes characteristic of high altitudes in Africa. The only other passerine birds in which regular temperature changes of this magnitude have been recorded are three members of the Hirundinidae.For Zosterops senegalensis and male N. mediocris a significant difference was found between the weights of birds caught at 2,690 m and those from 3,350 m.
CLUTCH CHARACTERISTICS AND EGG DISCRIMINATIVE ABILITY OF THE AFRICAN VILLAGE WEAVERBIRD PLOCEUS CUCULLATUS
Authors: Victoria J. K. 
Published: April 2008

SummaryOver a three‐year period, 917 eggs from 27 females were collected from a captive colony of African Village Weaverbirds Ploceus c. cucullatus. A study was made of egg‐laying and incubation behaviour, clutch characteristics and egg recognition.Fifteen yearling females laid their first clutches at a mean age of 348 days after hatching. The mean clutch‐size was 2.26 in adults and 1.68 in yearlings. The mean clutch replacement interval was 6.6 days in adults and 7.4 days in yearlings with an absolute minimum of 4 days. Eggs were laid at intervals of from 24 to 26 hours beginning usually 2–3 hours after dawn.The eggs laid by this species vary in ground colour and pattern of spotting between different females, but egg pigmentation is constant for each individual bird. The results of 322 egg‐replacement tests showed that an individual female could recognise her own egg type and would eject from the nest eggs differing markedly from her own. The incidence of rejection was proportional the degree of difference between the eggs. The possible implications for parasitism by the Didric Cuckoo Chrysococcyx cuprius are discussed.
THE EGG WHITE PROTEIN EVIDENCE FOR RATITE AFFINITIES
Authors: Sibley Charles G. , Frelin Christian 
Published: April 2008

SummaryThe egg white proteins of the large ratites (Struthio, Casuarius, Dromaius, Rhea), the kiwis (Apteryx) and several tinamous (Tinamidae) were compared with one another and representatives of several other groups of birds using the technique of isoelectric focusing in acrylamide gel. The tryptic peptides of the ovalbumins of the same groups were compared by thin‐layer electrophoresis. The results indicate that the large ratites are more closely related to one another than any one of them is to any other living bird; that the kiwis are not closely related to any of the other groups with which they were compared; and that the tinamous are not closely related to any of the large ratites but may be distantly related to the Galliformes.
COMPARATIVE ETHOLOGY OF THE CICONIIDAE. THE WOOD‐STORKS (GENERA MYCTERIA AND IBIS)*
Authors: Kahl M. P. 
Published: April 2008

SummaryThis paper reports on an 11‐year study of the comparative behaviour of the four species of wood‐storks. All species were studied under natural conditions at breeding colonies in the U.S.A., East Africa, India, and Indonesia. In addition, observations were made on hand‐reared young of two species (Mycteria americana and Ibis ibis).Various aspects of signal (display) and non‐signal behaviour are described. The most common ritualised display away from the nest is the Forward Threat. At the neBt, the following displays are seen, mainly during courtship and pair‐formation: Aerial Clattering Threat, Forward Clattering Threat, Snap Display, Anxiety Stretch, Flying Around, Gaping, Balancing Posture, Swaying Twig‐Grasping, Display Preening, Up‐Down, and Copulation Clattering. Each of these patterns is described in the text and many of them are illustrated.The four species treated here are similar to each other in most behaviour patterns. They do show some quantitative differences in courtship displays, particularly in the Up‐Down, a common “greeting” display shown to the mate at the nest.The behavioural and morphological evidence now available does not justify the separation of M. americana into a monotypic genus, and I suggest that all four wood‐storks be combined in the genus Mycteria. Thus, the wood‐storks include: M. americana, M. cinerea, M. ibis, and M. leucocephala.
THE IMPORTANCE OF CERTAIN ASSEMBLAGES OF BIRDS AS “INFORMATION‐CENTRES” FOR FOOD‐FINDING
Authors: Ward P. , Zahavi A. 
Published: April 2008

SummaryEvidence is presented to support the hypothesis that communal roosts, breeding colonies and certain other bird assemblages have been evolved primarily for the efficient exploitation of unevenly‐distributed food sources by serving as “information‐centres”.Predation‐pressure is regarded as being the most important factor “shaping” the assemblages. The shaping involves the choice of inaccessible or otherwise safe sites, optimum dispersal, mutual awareness of attack and joint defensive tactics, and serves to minimise the vulnerability to predation which would otherwise result when birds mass together in conspicuous, and often predictable centres.
SEA‐BIRDS AT LAGOS AND IN THE GULF OF GUINEA
Authors: Wallace D. I. M. 
Published: April 2008

SummaryRegular observations of sea‐birds were made in the vicinity of Lagos, southwest Nigeria, between October 1967 and June 1971. Records in the Gulf of Guinea were obtained in April 1969 and, together with others from Ghana and Sierra Leone, were used to complement this study. While few large populations of sea‐birds are supported, the diversity of species occurring at Lagos and over offshore deep water was great. The occurrence of nine species of sea‐bird new to Nigeria was established or confirmed; most of these were also new to West Africa southeast of Gambia. Details are given of fluctuations in numbers these and a further 16 species.All coastal habitats at Lagos supported a large population of immature Black Terns, and groups of immatures made up a high proportion of observations of other Palaearctic terns and of Royal Terns, which breed only in northwest Africa. In contrast, the Lesser Black‐backed Gulls and Damara Terns reaching Lagos (from breeding grounds almost two continents apart) were mainly adults; both these species are amongst those showing a current increase in numbers. A pronounced spring passage was observed among species including Royal and Sandwich Terns, but adult movements in autumn were not elucidated. The occurrence of the European race of the Little Tern in southwest Nigeria was confirmed, it is at least a regular spring migrant. The frequency of vagrants in January and February was linked to local climate as much to general distribution. Brief comment is also given on immature plumages, and the growing exploitation and pollution of coastal waters.
THE GIANT HUMMINGBIRD PATAGONA GIGAS IN ECUADOR
Authors: Ortiz‐Crespo Fernando I. 
Published: April 2008

SummaryThe Giant Hummingbird Patagona gigas was studied in highland Ecuador in 1968–70. The northern and southern limits of its known distribution were extended, but east‐west range and altitudinal limits were as restricted as noted by other authors. Its distribution elsewhere in South America is also reviewed, as are the taxonomy of various populations and breeding records. It is concluded that northern Ecuador is not reached by migrants from central Chile.Locally, Agave americana was the principal source of nectar, and the Ecuadorian range of the bird corresponds with the distribution of this plant. Further south, where the birds occur over a wider range of elevations, other plants are visited. It is suggested that the availability of nectar and the presence of competitors in combination determine the distribution of the Giant Hummingbird. The Ecuadorian population is probably prevented from northward extension by conditions unsuitable for Agave americana. There is evidence that this plant is exotic to Ecuador; its introduction may have permitted the Giant Hummingbird to expand its range from Peru.
THE FIORDLAND CRESTED PENGUIN EUDYPTES PACHYRHYNCHUS
Authors: Warham John 
Published: April 2008

SummaryAspects of the biology of Eudyptes paclzyrhynchus nesting on the west coast of the South Island of New Zealand were studied over six seasons. Nests occur in small scattered groups on steep slopes covered with heavy rainforest, beneath which the birds are protected from temperature extremes.After about four months at sea, the breeding birds return to land at the height of the southern winter. They aggregate in small, loosely organized groups, breed annually and tend to retain the same nest‐site and mate from year to year. They are ashore to breed for about 20 weeks before their chick departs. Incubation lasts for 31–36 days, and is undertaken in long shifts by both sexes in turn. It does not begin until the second and larger of the two eggs has been laid. The hatchling is guarded by the male for about three weeks, during which time it is fed almost daily by the female parent. The chick then joins a crèche and from then is fed by both parents until, at about 75 days old, it leaves for the sea. The parents also leave thereafter.Details are given of egg dimensions and weights, of egg loss, rates of chick‐growth, the fate of twins and of the food brought to the chicks. Egg and chick losses are high. The heavy rainfall and frequent storms seem major causes of loss. The birds seem incapable of rearing more than one chick, and when two are hatched a size disparity soon appears leading to the death of the smaller, apparently through starvation.The adults moult annually in the forest, often on their nests, after some 60 to 80 days spent at sea fattening up for this event. They fast for about 25 days before their new plumage is sufficiently well grown to permit their return to feed. Their whereabouts out of the breeding season are unknown.Display and associated behaviour are complex. They involve many dramatic attitudes in which the flippers and crests feature prominently accompanied by loud vocalizations.In an Appendix figures are given for dimensions of breeding pairs and details of other morphological differences between the sexes and between members of the present species and its closely related congener E. robustus.
SYNCHRONOUS FLUCTUATIONS IN POPULATIONS OF SOME RAPTORS AND THEIR PREY
Authors: Galushin Vladimir M. 
Published: April 2008

SummaryRaptorial birds which depend on a small number of prey species, especially those living in open habitats in the tundra, semi‐desert and desert belts of the Palaearctic, undergo local fluctuations in numbers which are synchronous with the fluctuations in numbers of their main prey species. In this they contrast with the asynchronous or lagging type of predator‐prey oscillation which has received wider attention in the literature.Evidence from ringing recoveries shows that the species which fluctuate locally in synchrony with their prey tend to move greater distances from their birth‐place or previous breeding place than those with more stable populations. The former species also tend to be split into fewer sub‐specifically distinct forms than the latter. It is argued that the species which are subject to a fluctuating food supply have evolved, as an important adaptation, the ability to undertake more or less extensive ‘searching migrations’, which enable them to find and settle in areas of adequate food supply, often far removed from the previous breeding area. In the longer evolutionary aspect, this ability may be a factor promoting food specialization.The synchronous population fluctuations of raptorial birds with their prey are compared with the asynchronous or lagging oscillations of carnivorous mammals.
SPRING MIGRATION OVER PUERTO RICO AND THE WESTERN ATLANTIC, A RADAR STUDY
Authors: Richardson W. John 
Published: April 2008

SummaryMigration over Puerto Rico was recorded by time‐lapse filming of the display of a long‐range surveillance radar on 40 days and 37 nights in the period 2 March‐29 May 1971. Moderate density movements occurred every night; low density movements occurred on most days. Many birds, primarily passerines, took off from Puerto Rico each evening at 20–45 minutes after sunset.Almost all birds flew to the west, NW or north. Birds were seen approaching from the direction of the Windward Islands and Venezuela, over Puerto Rico, and departing towards the Bahamas and eastern coast of the U.S. Uni‐ and multivariate analyses showed that the number of birds departing W‐N each evening was positively correlated with following winds.There is less night‐to‐night variation in the amount of migration at Puerto Rico than in eastern North America. However, this is apparently the result of less variable weather in the tropics, not the result of any lesser degree of meteorological selectivity by the migrants.The tracks of the birds were correlated with wind direction. Birds moved WNW‐NW with NE side winds but NW‐NNW with SE following winds. The tracks were rarely exactly downwind. The variance amongst the directions of individual birds at any given time was usually small and not correlated with cloud cover or magnetic disturbances. The estimated headings of the birds varied from day to day in a pattern suggesting adjustment of headings to compensate at least partially for lateral wind drift.In autumn many birds approach Puerto Rico from the north or even east of north; in spring few birds moved in the opposite directions. This difference in routes takes advantage of prevailing wind patterns.
THE ENDOCRINE BASIS OF PAIR‐FORMATION BEHAVIOUR IN THE MALE EIDER SOMATERIA MOLLISSIMA
Authors: Gorman Martyn L. 
Published: April 2008

SUMMARYPair‐formation behaviour among the Eiders began after the annual moult, in late September. There was a small peak of display in October and November and a large one in the following April and May. As a result, the female population became paired in two phases, up to 50% in the autumn and the remainder in the following spring.The seasonal cycle of the abundance of Leydig cells was bimodal, with a peak in October and a large one in April‐May. That the peaks represent increased androgen production was supported by the cycles of Leydig cell enzyme activity and lipid content and of penis weight. The monthly means of Leydig cell abundance and of the rate of display were statistically correlated. Experiments with sexually quiescent males in eclipse plumage demonstrated that testosterone was capable of inducing pair‐formation behaviour.Relatively advanced stages of spermatogenesis were found in autumn, and were maintained through the winter, complete development occurring in the spring. Seasonal changes in the production of pituitary gonadotropin followed a bimodal pattern with peaks in autumn and in the spring. Field evidence is presented which suggests that Follicle Stimulating Hormone and Luteinizing Hormone were produced at different phases of a circadian rhythm of photosensitivity.
ORDINAL AFFINITIES OF THE AEGIALORNITHIDAE
Authors: Harrison C. J. O. 
Published: April 2008

SummaryThe Aegialornithidae of the Eocene‐Oligocene, previously regarded as swifts, have been transferred by Brodkorb (1971) to the nightjar order Caprimulgiformes. The fossil forelimb bones representing this early family have now been compared with those of recent species of the true swifts and tree swifts (Apodi in Apodiformes) and with nightjars, Oilbirds and frogmouths (Caprimulgiformes). The corresponding bones in swifts differ consistently from those of nightjars in the greater development of various prominences for muscle attachment. In all critical characters the fossil bones resemble those of swifts, and it is concluded that the Aegialornithidae should be reinstated as a family of the Apodiformes.
THE THERMAL SIGNIFICANCE OF THE NEST OF THE SOCIABLE WEAVER PHILETAIRUS SOCIUS: WINTER OBSERVATIONS
Authors: White Fred N. , Bartholomew George A. , Howell Thomas R. 
Published: April 2008

SummaryThe Sociable Weaver of southern Africa builds the largest of all birds' nests. Individual nests contain many chambers and may be occupied by a colony of a hundred or more pairs. Most aspects of the biology of this species are linked, either directly or indirectly, to the nest and its construction. One readily demonstrable function served by this enormous nest is the amelioration of the impact of low environmental temperatures.
ECOLOGY AND BEHAVIOUR OF THE SOUTH GEORGIA PINTAIL ANAS G. GEORGICA
Authors: Weller Milton W. 
Published: April 2008

SummaryA study of the feeding ecology and breeding biology of the South Georgia Pintail was conducted in East Cumberland Bay during November and December 1971. Of a variety of water areas available, pintails fed and reared their broods in tussock‐trimmed ponds. The second most important feeding areas were sheltered fjords and seashores. Food included freshwater invertebrates such as fairy shrimp, marine amphipods and snails, and small amounts of marine algae. Considering the climatic conditions, the breeding season spans a long season from late October to early March. Courtship and social behaviour are very similar to that of the pintail, and displays and calls could not be differentiated from those of A. g. spinicauda.There is now one other species of duck on South Georgia, the Speckled Teal, but, because it occurs sympatrically with A. g. spinicauda throughout temperate South America and tends to use different food resources, no serious competition is expected.It is concluded that these species have successfully adapted to South Georgia because of the availability of protected, food‐rich ponds for rearing young and because of the semimarine adaptations that have developed in Tierra del Fuego and the Falkland Islands.
BIOLOGY AND BEHAVIOUR OF FRIGATEBIRDS FREGATA SPP. ON ALDABRA ATOLL
Authors: Diamond A. W. 
Published: April 2008

SummaryBoth species nested in mixed colonies in mangrove trees. The tops of trees were usually occupied exclusively by minor and the lower parts by ariel, but most nests of both species were in the intermediate parts of the canopy. The main laying season for both species was July to January. A census showed about 27 000 individuals present at the height of the season (1500 breeding pairs of minor, 5350 of ariel). Seasonal variation in numbers could be accounted for almost entirely by the changes in breeding activity of a resident population. Young of both species were fed at or near the nest‐site for at least four months after fledging. A recovery near Bombay of a wing‐tagged immature ariel shows that this species, at least, undergoes a post‐fledging dispersal; it is suggested that young minor either do not disperse, or do so later than ariel.Food samples collected from chicks showed no overall difference between the species, but a seasonal analysis showed that ariel took more squid than minor in the wet season, and in the dry season the two species took different proportions of the two commonest species of flying‐fish. Chicks of ariel received smaller meals than minor chicks in the wet season, but similar‐sized meals in the dry season; ariel chicks grew more slowly than minor chicks. It is suggested that the timing of the breeding season is related to the need for adults to build up fat reserves to carry them through the courtship, nest‐building and laying periods, when they are tied to the colony and so have little opportunity to feed.The evidence for non‐annual breeding in frigatebirds is discussed. It is concluded that while successful breeders must breed at intervals of more than 12 months, they could theoretically nest in two successive seasons and that, since breeding success is low, most individuals probably do so.Existing knowledge of the biology of four of the five recognized species of frigatebirds is summarized, and shows that the family is at least as uniform as the tropicbirds and much more so than other Pelicaniformes.
SUMMER SEABIRD DISTRIBUTIONS IN DRAKE PASSAGE, THE CHILEAN FJORDS AND OFF SOUTHERN SOUTH AMERICA
Authors: Brown R. G. B. , Cooke Fred , Kinnear P. K. , Mills Eric L. 
Published: April 2008

SummaryThe paper summarizes observations on the pelagic distributions of sea‐birds in Drake Passage and off southern South America, collected by ship‐borne observers between December 1969 and April 1970, and in March and April 1972. The birds' distributions have been related to sea surface temperatures and, in the case of the Chilean fjords, to water types defined in terms of temperature and salinity; a partial attempt has been made to relate them to the distribution of the macroplankton.The boundary between the ranges of Phalacrocorax albiventer and P. atriceps in the Chilean fjords is much farther west than previously reported, and there is some evidence that it has moved westwards within the last 20 years. It is suggested that its position is determined by oceanographic rather than climatic factors.A sighting of Pterodroma macroptera in Cockburn Channel is the first record of this species for Chile. Exceptionally southerly records of Lobipes lobatus in Magellan Strait, and Pterodroma mollis south of the Antarctic Convergence are also described. An apparent decline in the numbers of Pterodroma neglecta at Masatierra, Juan Fernandez, is noted.
THE OCCURRENCE AND SIGNIFICANCE OF ANOMALOUS REPRODUCTIVE ACTIVITIES IN TWO NORTH AMERICAN NON‐PARASITIC CUCKOOS COCCYZUS SPP.
Authors: Jr Val Nolan , Thompson Charles F. 
Published: April 2008

SummaryAmong the unusual breeding habits of the non‐parasitic Yellow‐billed and Black‐billed Cuckoos of North America are great variability in clutch size and rate of laying, initiation of incubation long before the clutch is complete, occasional laying in nests of other species, annual irregularity in the timing of the breeding season, and semi‐nomadic post‐migratory movements into breeding areas where food is abundant. These facts, in addition to their peculiar diet and the very large size of their eggs, suggest that cuckoos have extraordinary problems in obtaining adequate energy for reproduction.At Bloomington, Indiana (U.S.A.), during a 15‐year period, anomalies in the reproductive activities of cuckoos were concentrated into two years in which food was abundant. This was particularly true of one of these years, when there was a vast emergence of periodical cicadas: the Yellow‐billed Cuckoo advanced its normal schedule and bred during peak cicada abundance, laid unusually large clutches, and parasitized Black‐billed Cuckoo nests. Some females may have resumed laying in nests in which, having already deposited clutches of normal size, they had been incubating for long periods; the alternative possibility is that there was intraspecific brood parasitism.The erratic egg‐laying behaviour of these cuckoos is attributed to the evolution of mechanisms permitting very quick exploitation of a favourable feeding situation. It is suggested that reproductive behaviour has become so responsive to an abundance of food that normal ordering and integration of the stages of breeding have been lost in some females. Such a loss could be responsible for the laying of eggs in alien nests, and it may have been the antecedent of obligate brood parasitism in parasitic cuckoo species.