bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE FEEDING HABITS OF THE WOODPIGEON COLUMBA PALUMBUS, STOCK DOVE C. OENAS AND TURTLE DOVE STREPTOPELIA TURTUR
Authors: Murton R. K. , Westwood N. J. , Isaacson A. J. 
Published: April 2008

SummaryThe feeding‐sites of Woodpigeon, Stock Dove and Turtle Dove were examined in a study area in Cambridgeshire by making repeated standardized observations over five years. The crop contents of 614 Woodpigeons and 166 Stock Doves shot throughout the period were analysed to determine the birds' diet. Seasonal variations are detailed. The crop contents of 41 Turtle Doves, and the nestlings of 14 Stock Doves and 5 Turtle Doves were also analysed.During the winter, Woodpigeons fed primarily on clover leaves which they collected from leys and pastures, but also on weed leaves and, during periods of snow, those of various cultivated brassicae. Grain was taken from the spring cereal sowings, after which the birds reverted to clover feeding, supplementing this diet with tree leaf and flower buds. When cereals ripened these comprised the main food being collected from July to November, at first from standing crops and then from stubbles. Wheat was preferred to barley. In the autumn, beech nuts, acorns and other tree fruits were taken and when stocks of these and the cereals were exhausted the birds turned again to clover feeding. Weed seeds, especially pasture species, were collected especially in May and June but only in small amounts.Stock Doves fed primarily on weed seeds throughout the year, obtaining these from fallow ground, ploughed fields and cereal stubbles. Cereal seed was taken when available, but featured less in its diet than that of the Woodpigeon. The most important weed seeds were Sinapsis and Brassica species, Stellaria media capsules and Polygonum and Chenapodium species. Leaves or tree buds and fruits were not an important food item.Turtle Doves fed primarily on the seeds of Fumaria and grass species, but they also collected cereal grains and Stellaria media capsules. They collected their food from waste ground or from tall, standing hay or corn crops, where many weeds were growing. They did not appear to feed from trees or hedgerows.The food of nestling Stock and Turtle Doves was similar to that collected by the adults for themselves.The feeding habits of the other British columbids is briefly reviewed. It appears that the Turtle Dove, Stock Dove and Woodpigeon, and also the feral pigeon and Collared Dove occupy different ecological niches, the first three associated with arable farmland. The Woodpigeon, Stock Dove and Turtle Dove have all increased in numbers and range following the development of agriculture. It is likely that the Rock Dove competes for food with the Stock Dove and possibly at times with the Woodpigeon, which probably explains the declining status of the Rock Dove in Britain.The distribution of the Turtle Dove in Britain is similar to the distribution of Fumitory, its major food plant.
HEAT LOSS IN WET DUCKLINGS AND CHICKS
Authors: Nye Pauline A. 
Published: April 2008

SummaryWet ducklings, like wet chicks, had lower body temperatures than dry birds. The temperature depressions of the chicks decreased as they grew older. The temperature depressions of the ducklings were mainly dependent on the waterproofing of their plumage and how much of their skin became wetted. Completely waterproof ducklings, which maintained a layer of air between their skin and the water, lost heat slowly, but poorly waterproofed birds with wet skins lost heat quickly. Waterproofing was reduced in the laboratory when the ducklings' feathers became soiled and disarranged and when one swam in soapy water.
SOME ASPECTS OF TAXONOMY AND RELATIONSHIPS OF BARBETS (CAPITONIDAE)
Authors: Goodwin Derek 
Published: April 2008

SummarySome aspects of the taxonomy and relationships of the barbets are discussed and illustrated, with special reference to the recent classifications of the family by Ripley and by Peters. The colour pattern of the head appears to function as a species‐specific recognition mark. Sympatric species of similar size usually differ strikingly in head colouration. There are several examples of apparent character displacement. The genus Psilopogon is considered to be closely allied to Megalaima. Megalaima lagrandieri forms a link between the two genera. The resemblances between Calorhamphus and Gymnobucco are due to convergence. The latter genus is very closely related to the species placed in Stactolaema. Lybius chaplini is thought to be closer to L. rubrifacies than to L. leucocephalus. The mobility of the rictal bristles of a living Megalaima asiatica is described.
THE REPRODUCTIVE BEHAVIOUR AND TAXONOMY OF HEMPRICH'S GULL LARUS HEMPRICHI
Authors: Fogden M. P. L. 
Published: April 2008

SummaryObservations were made in the sea bird colonies of the Kiunga Archipelago in Kenya, in 1961. The islands are described and the numbers of the five species of sea birds (one gull and four species of terns) which were found breeding on the islands visited are recorded. The principal predators in the colonies are man and Hemprich's Gull Larus hemprichi.Particular attention was paid to the reproductive behaviour of hemprichi which is a tropical hooded gull with extensive areas of dark plumage. Dark plumage in gulls is disadvantageous to plunge‐diving for fish; hemprichi is almost entirely a scavenger. Hemprichi is not a social breeder and as a rule there is only one pair on each island. It is also relatively non‐territorial.In the most recent revision of the Laridae, hemprichi is classified as a “‘primitive’ hooded gull”, but in fact its behaviour complex is not characteristic of this group. The displays of hemprichi are described and compared in detail with the homologous displays of “primitive” hooded gulls, masked gulls and the large white‐headed gulls in the taxonomic sense.These displays are all except one (Facing Away) very similar to those of the Herring Gull L. argentatus (a large white‐headed gull). By treating the displays as taxonomic characters, it is concluded that hemprichi is a large white‐headed gull which has acquired a hood and dark plumage, this change being facilitated by its having become a scavenger (and thus not dependent upon white plumage as an adaptation to plunge‐diving), and by some other factor possibly connected with tropical insolation.Evidence is put forward which shows that the White‐eyed Gull L. leucopthalmus, another tropical hooded gull superficially similar to hemprichi, is also a large white‐headed gull.
LIFE HISTORY OF THE BLUE‐DIADEMED MOTMOT MOMOTUS MOMOTA
Authors: Skutch Alexander F. 
Published: April 2008

SummaryOver a wide geographical and altitudinal range, extending from sea level up to at least 7,000 feet in Costa Rica, the Blue‐diademed Motmot has adopted a great variety of habitats.It lives in pairs through most, if not all, of the year.Its food consists of a variety of insects, especially beetles, and small fruits.Pairs or trios apparently engaged in courtship hold pieces of green leaf or other fragments of vegetation in their bills, although they never take such material into their nests.Nesting burrows, up to 7 feet long, are usually dug from the side of a hole in the ground, rarely in an exposed bank where the entrance is conspicuous. Excavation begins in the wet season, from late August to October, and may continue for 21/2 months, chiefly in the late morning and early afternoon, when the soil is driest, at an average rate of little over one inch per day. Until the beginning of nesting at the end of the following dry season, the burrow is not used for sleeping and is rarely visited.In March or April, three white eggs are laid on the bare floor of the nest chamber. Both sexes incubate. One enters the burrow soon after noon and stays until the following dawn. After 15–30 minutes the mate enters and sits for about seven hours. The incubation period is about three weeks.The nestlings hatch completely naked. The nestling period is 29–32 (once 38) days. Brooding, even at night, ceases before the young are a week old, although they are still naked. Both parents bring them a variety of insects, chiefly beetles, small fruits, and occasionally a small snake, lizard, or bird. At one nest the rate of feeding increased up to the nestlings' nineteenth day, when each was fed 2·3 times per hour.After the nestlings' departure, neither parents nor young sleep in the burrow. The species is single‐brooded in Costa Rica.
THE BIRDS OF THE DAHLAC ARCHIPELAGO
Authors: Clapham C. S. 
Published: April 2008

SummaryThe Dahlac Archipelago, in the southern Red Sea, is described. Eighteen of its islands were visited by an expedition in August and September 1962, and 33 species, excluding migrants, were recorded. The distribution of these species between islands is summarized (Table 2), and observations are made on their habits, habitats, food, and liability to predation. Evidence of breeding is given for Sula leucogaster, Falco concolor, Larus hemprichi, L. leucopthalmus, Sterna bengalensis and Sauropatis Moris; breeding is also suggested for five further species.Particular attention is paid to Falco concolor, and existing knowledge of this species is summarized. Information is given about breeding biology, food, hunting methods, call and other habits, and the species is compared with F. eleonorae, from which it differs chiefly in the absence of colonial breeding.The breeding biology of Sula leucogaster is briefly discussed, and attention is paid to the differences between Larus leucopthalmus and L. hemprichi.
DISTANCE NAVIGATION IN THE ADELIE PENGUIN
Authors: Emlen J. T. , Penney R. L. 
Published: April 2008

SummaryMale Adelie penguins Pygoscelis adeliae were transported from coastal rookeries in the Ross Sea area of Antarctica to three release points on featureless ice plateaux in the interior of the continent. Birds were released individually and their departure routes mapped for distances of 2–4 km., the position of the bird being determined by triangulation every five minutes. Precise data were thus obtained on the straightness of course and direction selected by each of 103 birds.Birds released inland from a coastal rookery under favourable conditions consistently moved in straight courses N.N.E. toward the coast. Birds from the same rookery released at points to the east and west took courses essentially parallel to this departure direction, i.e., northwest and northeast respectively on a meridian scale rather than true north or in the homeward direction. These and other experiments under varying degrees of cloud cover and with birds prepared under artificial day‐night light regimes indicate that the birds possessed a navigation mechanism which used the sun as the primary orientation cue plus a biological clock to compensate for changing sun azimuth positions. The mechanism effected a consistent escape direction for birds of a given population (source) regardless of the location of the release site.The “grid N.N.E.” orientation of these birds is compared with “nonsense orientation” as described for ducks and other birds. It is considered to have survival value in the present instance in steering lost penguins to the appropriate off‐coast feeding areas and in segregating and concentrating the birds from the various circum‐continental populations.
FEEDING ECOLOGY OF THE BLACK‐FACED DIOCHQUELEA QUELEAIN NIGERIA
Authors: Ward P. 
Published: April 2008

SUMMARYThe results of a three‐year study of the diet ofQuelea queleain the Lake Chad region of Nigeria indicate why this bird periodically does extensive damage to crops of dry‐season guinea‐corn.The normal food of the birds in the early dry‐season consists of small grass seeds collected off the ground. As the supply of these diminishes there is a gradual change‐over to larger seeds.In years when this change begins early, it is liable to coincide with the ripening of the cereal crop and severe damage may be caused.At the beginning of the rains the dry‐season food supply is lost owing to the simultaneous germination of the seeds over large areas.The birds lay down fat reserves in preparation for this lean period.After a short time the birds migrate south to regions where rain has been falling for some weeks.In the short period spent in these parts, Queleas feed on ripening grass seeds—including those of cultivated millet.There is evidence for considerable mortality during this time of food scarcity and it is suggested that the numbers of Queleas are limited by the food supply.The significance of communal roosting is discussed. It is proposed that the phenomenon is related to food finding, the roost being considered as an “information centre” for the large area prospected by the birds constituting the roosting community. A method is outlined by which information on food availability within the feeding area may feasibly be transmitted within the community.
DETECTION BY RADAR OF AUTUMN MIGRATION IN EASTERN SCOTLAND
Authors: Wilcock John 
Published: April 2008

SUMMARYRadar observations through one autumn in Aberdeenshire are described showing that more migration takes place in anticyclonic weather than transitional weather, and even less migration takes place in disturbed weather. More migration is detected by radar with following winds than with opposed winds.Comparison of data collected in Norfolk and Aberdeenshire during one season at each shows that more migration is detected by radar in Norfolk, and westward movements, which are a feature of migration into Norfolk, appear in Aberdeenshire only when birds are first drifted northwards.Dawn ascent and reorientation movements of birds in the northern North Sea are described, showing that changes in heading were consistently between S.W./S.S.W. and S.S.E. during the autumn studied.Weather data, radar data and ground observer data from Aberdeenshire and the Isle of May Bird Observatory were analyzed and show again that the normal migration pattern is to fly high with following winds and low only with opposing winds as in Norfolk. However, the weather in Aberdeenshire was more disturbed than it had been in Norfolk, with the consequence that weather factors, other than wind, which affect the normal migration pattérn were found to be much more common.
MIGRATION ACROSS THE MEDITERRANEAN OBSERVED BY RADAR
Authors: Casement M. B. 
Published: April 2008

SUMMARYBird migration across the Mediterranean was studied by radar from an aircraft carrier for brief periods during the springs of 1961, 1962 and 1963 and in the autumn of 1963.The radar displays were photographed and analysed to give intensity (scales 0 to 6) and tracks have been plotted on the accompanying Maps together with Tables setting out the weather data and records of bird sightings. Most echoes that could be measured were between 4,000 and 6,000 ft. Small (passerine) echoes usually moved at 20–30 knots, large ones (presumed to be waders, ducks, etc.) at up to 47 knots.The analyses of each of the nine sets of observations are discussed in detail from the Atlantic to the south of Crete, including the Aegean. There is clear evidence, within the limitations of the stated methods used and the dates of observations, that migration takes place along the whole length of the Mediterranean at almost uniform density except across the Ionian Sea, where it is greatly reduced. This is possibly because the long desert crossing and the long sea crossing are separated by only a very narrow coastal strip of vegetation and there is obvious survival value in crossing further east or west. There is no evidence for concentration across the Sicilian narrows, through Malta or across the Straits of Gibraltar. The direction of migration west of the Ionian Sea is N.E./S.W. and to the east is N.N.W./S.S.E.A large‐scale movement was observed coasting 20 miles offshore from Portugal in autumn tracking S.W. off Cape St. Vincent. This area in particular deserves further investigation as also does the area south of Crete.Migration is considerable at least from 18 August‐24 October. The main departure of small migrants from land starts 40–50 minutes after sunset and tails off with the dawn. The diurnal pattern of intensity observed at sea is noted and it is suggested that the shape of the build‐up and the time of the peak can provide a clue as to the point of departure. There are indications that in spring, especially south of Crete, some migrants do not rest in the narrow coastal strip but cross the Sahara Desert and the Mediterranean Sea non‐stop.The significance of the results is discussed in the light of further visual observations made in 1964 and 1965.
AUTUMN AND SPRING WEIGHTS OF SOME PALAEARCTIC MIGRANTS IN CENTRAL NIGERIA
Authors: Smith V. W. 
Published: April 2008

SUMMARYDuring the winters 1963/64 and 1964/65 some 700 weights of 19 species of Palaearctic migrants caught in Central Nigeria were obtained. Where there were adequate weights for analysis, mean weights in the spring were significantly heavier than mean autumn weights; mean weight gains in the spring varied from 47% (Pied Flycatcher) to 21% (Garden Warbler and Spotted Flycatcher). Individual gains were higher.
BREEDING BIOLOGY OF THE MANX SHEARWATER PUFFINUS PUFFINUS
Authors: Harris M. P. 
Published: April 2008

SUMMARYStudies on the breeding biology of Puffinus puffinus were carried out in 1963 and 1964 at the large colony on Skokholm, Wales.During the six weeks before laying the birds spent up to a quarter of the days in the burrows, but the ten days immediately prior to laying were normally spent at sea.There is a prolonged laying period, with a marked peak in the first half of May. Details are given of a second egg being laid when the first was deserted immediately after being laid.The male took the first incubation spell. The incubation spells ranged from one to 26 days and averaged six. The incubation period was about 51 days. The frequency of visits to land by breeding birds, unlike those by non‐breeders, was not affected by the moon.On hatching, the chicks grew rapidly and reached maximum weights of between 505 and 755 gm. sometime between 39 and 61 days. There was a variable desertion period, usually eight or nine days, before the chicks left the island about 70 days after hatching. During the feeding period the chick received about two feeds every three days. There is evidence that adults visited the chicks more frequently than this. There was no correlation between growth of the chicks, their feeding rates or fledging weights and the time of laying.There was a high survival (about 95 %) of chicks during the fledging period but some eggs were lost in disputes for burrows.Nine pairs in 1964 were unable to raise two young simultaneously. Parents altered their feeding rhythms to try to feed two young but did not themselves lose weight.It is suggested that the critical factor in the production of young is the availability of food for the young immediately after they leave the colonies.
OBSERVATIONS ON THE BEHAVIOUR AND ECOLOGY OF THE FLIGHTLESS CORMORANT NANNOPTERUM HARRISI
Authors: Snow Barbara K. 
Published: April 2008

SUMMARYFrom 25 September to 8 October 1963 daily observations were made on a group of Flightless Cormorants Nannopterum harrisi nesting on the west side of Albemarle Island in the Galápagos.Flightless Cormorants are apparently bottom‐feeders, and confined to shallow coasts at the western end of the Galapagos Archipelago where there is an upwelling of cold nutrient‐rich water. There is no reason to suppose that they are declining in numbers.Males are very much larger than females, the size difference between the sexes being greater than in other species of cormorants.Courtship behaviour, nest‐building and mating are described. The earliest phases of courtship take place on the water, later phases at the nest‐site. Homologies are traced with other cormorant species. In contrast to other members of the family, allopreening apparently does not occur.Both sexes incubate and care for the young. Observations on families of different ages over the 12‐day period allowed the development of the young to be traced up to the age of about 40 days.Egg‐laying takes place in most months of the year, with a peak in April‐June and perhaps a second peak about October. Observations on birds colour‐ringed on an earlier visit suggested that individuals do not breed more than once in the year. Nesting success appeared to be very low in 1963.
NOTES ON THE ECOLOGY OF THE CATTLE EGRET ARDEOLA IBIS AT ROKUPR, SIERRA LEONE
Authors: Craufurd R. Q. 
Published: April 2008

SUMMARYThe Cattle Egret is a dry season visitor to Rokupr in Sierra Leone during the bird's non‐breeding season. There are no cattle in the area to attract the herons and they obtain nearly all their food from small isolated areas of vegetable gardens which are associated with all the villages. The number of herons associated with each garden is closely correlated with the area of that garden and is about two birds per acre.The daily life of the birds is discussed, in particular the pre‐roosting assemblies and the flight to roost, and it is shown that each flock leaves for the roost at the same time each day, about 30–35 min. before dusk.Observations made at a particular roost showed that all the Cattle Egrets reached the roost before dusk and from these observations, combined with those made on the feeding grounds, it is concluded that the number of Cattle Egrets using the roost is determined by the number and area of the feeding grounds that lie within 30–35 minutes flying time (about 12 miles) of the roost.Other species using the roost are briefly discussed.
SUBFOSSIL PETREL BONES FROM THE CHATHAM ISLANDS
Authors: Bourne W. R. P. 
Published: April 2008

SummaryThe breeding community of petrels on the Chatham Islands has previously seemed curiously poor compared to that of analogous stations in the Indian Ocean or South Atlantic (14 species compared with 18 in the Tristan‐Gough group). Examination of subfossil deposits from the Chatham Islands probably dating from the early stages of human colonization which occurred within the last few hundred years reveals remains of at least 20 petrels, all of which except one may well have bred in the past, without including storm petrels, of which two species are still known to breed while others may also have bred in the past. The grand total of at least 21 breeding species, many apparently in vast numbers, would probably make the archipelago the most important breeding station for petrels in the world at the time of the first human colonization. It seems possible that in addition to the present breeding species the following may have bred: at least one endemic species of gadfly petrel, the Magenta Petrel Pterodroma magentae, and local populations of at least two other gadfly petrels, two shearwaters of the genus Procellaria and two of the genus Puffinus and a sooty albatross of the genus Phoebetria. Small populations of these, and perhaps other undetected species as well, may still survive in inaccessible places.