bluuebunny/crossref_metadata_2025_split huggingface dataset:
TAXONOMIC COMMENTS ON THE EURYLAIMIDAE
Authors: Olson Storks L. 
Published: April 2008

SUMMARYOn the basis of supposed differences in the shape of the spina externa of the sternum, the number of cervical vertebrae, the deep plantar tendons, the quadrato‐jugal articulation, and the size of the hallux, the Eurylaimidae were put in a separate suborder, the Eurylaimi. All of these characters are now shown to be variable within the family or shared with other suboscine families. It is recommended that the subordinal designation “Eurylaimi” be abandoned and that the family be included in the suborder Tyranni. A number of characters point to the Cotingidae as the nearest possible extant relatives of the Eurylaimidae. The Eurylaimidae consist of a number of unrelated genera with several relict species, and probably represent the remains of an ancient, once more widespread group that became isolated and gave rise to the suboscine fauna in South America while being largely replaced by oscines in the Old World. Recognition of subfamilies within the Eurylaimidae is discouraged. Smitkornis should be considered the most advanced of the eurylaimids. The sequence of suboscine families is discussed and a rearrangement is suggested.
THE ANNUAL RE‐OCCUPATION OF BREEDING SITES BY THE FULMAR
Authors: Coulson J. C. , Horobin Jean M. 
Published: April 2008

SummaryThe Fulmar has a long period at the breeding colony prior to egg‐laying. The pattern of annual occupation and build‐up in numbers has been examined in detail at Marsden, Co. Durham, at a colony in which over 100 eggs are laid annually (Order 3 of Fisher's classification).The re‐occupation of the cliff starts in early November with an occasional visit by one or two birds. The main period of activity at the cliff is during the morning and, as the numbers build up, the diurnal period of occupation increases. By mid‐December the first birds to arrive in the colony do so before dawn and the last to leave remain well after dark until near midnight. Almost throughout the pre‐egg stage, the colony is deserted each night and re‐occupied the next day and birds only stay regularly overnight just before egg‐laying. A similar pattern of occupation occurs after breeding but in the reverse order.The numbers of birds at the colony in January and February exceed the breeding population and include many non‐breeders. The non‐breeders progressively decline in numbers until May when only the breeding birds remain with a few non‐breeding birds.The daily variation in the numbers of birds at the cliff is influenced by the wind speed. In general, the birds leave the colony under freshening conditions and the number present at the colony can be interpreted in terms of the wind conditions over the last three days.It is suggested that the synchronised departures are primarily feeding trips, the birds using the strong winds to reach feeding areas, except that the departure just before egg‐laying is linked to egg development and synchronised laying in the colony.Competition between Fulmars and Kittiwakes for nesting sites usually results in the Kittiwakes gaining the site. This is achieved by the Kittiwakes taking over the Fulmar sites during one of the latter's departures.
THE CONTAMINATION OF BIRDS' FEATHERS BY FUNGI
Authors: Pugh G. J. F. 
Published: April 2008

SummaryFungi have regularly been recorded on feathers removed from birds. Cellulose‐decomposing spores which are merely carried on the feathers were common on birds sampled in Britain, but were fewer than expected on the basis of random distribution on birds sampled in India. Hyaline‐spored fungi were less common on Indian birds, and more abundant on British birds than expected. Keratinophilic fungi, which are related to the dermatophytes, were particularly associated with related groups of birds: thus Turdus spp. regularly yielded Arthroderma curreyi, and partridges were contaminated with Ctenomyces serratus. Chrysosporium spp. were widespread on birds in India and Britain. Where associations have been shown, feather fats from these birds stimulate, or do not depress the growth of the keratinophilic fungi. Otherwise, feather fats were inhibitory to the fungi. The temperature relationships of the fungi, showing no growth at 40°C, would explain the restriction of the keratinophilic fungi to the outer, contour feathers, and of dermatophytes mainly to the non‐insulated parts of the birds' surface.
ON MULTIPLE BROODS AND THE BREEDING STRATEGY OF ARCTIC SANDERLINGS
Authors: Parmelee D. F. , Payne R. B. 
Published: April 2008

Summary.Sanderlings on Bathurst Island in the Canadian arctic have two patterns of incubation. At some nests the eggs are covered soon after the fourth egg has been laid and at others incubation is delayed for 5–6 days. Because the delay is about the same time required to lay a second clutch and because a single individual alone incubates at any one nest, we suspected that Sanderlings might normally lay two clutches in a season, the male caring for one brood and the female for the other.Histological and gross examination of the ovaries of two females taken as the birds began incubation showed eight freshly ovulated follicles in each female. The size gradation and histological appearance of the follicles indicated that two clutches of four eggs each had been laid within 8–10 days by a single female. The ovary of one female had additional large yolky follicles, suggesting a physiological capability of further ovulations.Field conditions in the arctic summer are highly variable, and the small eggs and the rapid sequence of broods of Sanderlings may be breeding adaptations that permit them to multiply the traditional wader clutch of four eggs by 2 or 3 in favourable years. Selection for mating systems characterised by brief pair bonds and by polyandry is expected in precocial birds where some broods are incubated and cared for by the male, but further field work is required to determine the precise mating system of Sanderlings.
AN INVESTIGATION OF PHOTO‐REFRACTORINESS IN THE HOUSE SPARROW BY ARTIFICIAL PHOTOPERIODS
Authors: Murton R. K. , Westwood N. J. 
Published: April 2008

SummaryThe natural testis cycle and associated changes in bill colour of the House Sparrow Passer domesticus are described. Subjects were wild‐caught at three different times in the breeding cycles:in February when the testes were small and contained only spermatogonia, in May when they were fully recrudesced and contained bunches of spermatozoa and in late July at a time when spontaneous gonad regression was occurring as the birds entered their photo‐refractory phase. Each sample was divided into eight separate groups which were given a range of artificial asymmetric skeleton photo‐periods generalized as LD 6 +1/2:131/2; the 1/2‐h light pulse was given at a different point in the dark period in each group.The birds entrained to skeleton schedules simulating complete photoperiods of up to 12 h duration as if the start of the long light pulse was dawn. However, with long‐day simulations (e.g. 6L 111/2 D 1/2 L 6D which simulates an 18 h photoperiod) the birds entrained to the start of the short light pulse to give an effective photoperiod of 121/2 h (that is, 1/2L 6D 6L 111/2D). The skeleton schedules simulating 14 h and 16 h were interpreted as such in February and were not effective in causing testicular induction, but they were apparently read as days of 161/2 h and 141/2 h in May, and as such maintained active spermatogenesis. The differences are discussed in terms of the changed frequency of a circadian oscillator. When birds captured in July were held on the various skeleton light schedules refractoriness was ended for most the subjects, as was proved by subsequently exposing them to a complete 16‐h photoperiod. Exceptions were the birds in the group given the 14‐h simulation, for these entrained as they had in May and so were effectively receiving a long 161/2‐h day. The discussion presents evidence to show that photoperiods in excess of 14 h cause the light sensitive phase of a circadian oscillator responsible for luteinizing hormone secretion to be phased into the non‐inductive period of darkness. Rehabilitation of the interstitial components of the testis is apparently inhibited in such circumstances.
DIALECTS AND GEOGRAPHICAL VARIATION IN THE SONG OF THE SPLENDID SUNBIRD NECTARINIA COCCINIGASTER
Authors: Grimes L. G. 
Published: April 2008

SummaryThe male Splendid Sunbird has only one song type, each note of which has a simple frequency/time profile. An analysis of the songs of males from several localities near Legon (5.63° N, 0.19° N) showed that there are clear‐cut song dialects characterizing each population. Those parts of the song giving rise to dialects are the time interval between consecutive pairs of notes (the time interval pattern) and the frequency/time profile of each note.The dialects were preserved over a period of three years (the duration of the study) and there was little variation in the song of a ringed bird over a period of two months. The boundary between dialects is apparently quite sharp, occurring perhaps within a distance of 50 m.Marked geographical variation in the song occurs, and is expected because of the mosaic of dialects that presumably exist throughout the sunbird's range in southern Ghana. For dialects to be effective in keeping populations together, those characteristics of the song which give rise to dialects should be readily and quickly discerned and need not require a statistical demonstration. This condition holds for the song of the Splendid Sunbird.The results are compared with the ideas of Nottebohm (1964) and Thielcke (1969) on the maintenance and usefulness of song dialects.
Books
Authors: L. J. H. 
Published: April 2008

Batten, L. et al. 1973. Birdwatchers' year. Pp. 351, 18 black and white photographs, numerous text‐figures. BerkhamstedClancey, P. A. 1971. A handlist of the birds of southern Moqambique du Pont, J. E. 1971. Philippine birdsFarner, D. S. & King, J. R. (Eds) & Parkes, K. C. (Taxonomic editor). 1972Tinbergen, N. 1973. The animal in its worldWetmore, A. 1972. The birds of the Republic of Panami
LAKE RUDOLF AND THE PALAEARCTIC EXODUS FROM EAST AFRICA
Authors: Fry C. H. , Britton P. L. , Horne Jennifer F. M. 
Published: April 2008

SummaryThe 165 000 km2 sub‐desert corridor in which Lake Rudolf lies may affect the routes taken by Palaearctic migrants in eastern Africa. A five‐week study was made at Lake Rudolf during the spring migration period. The area is important for water birds, especially waders. It is less important for land birds, although on passage several passerines occur abundantly on Central Island, and some commonly in similarly well vegetated area (Turkwel river, littoral reedbeds). Some may fatten there before emigrating. Evidently the sub‐desert corridor is not so inhospitable that it is entirely avoided or overflown by migrants.
TRANS‐SAHARAN MIGRATION THROUGH SARIR, 1969–70
Authors: Hogg Peter 
Published: April 2008

SUMMARYAn account is given of observations made at the BP/Bunker Hunt Oil Production Centre at Sarir in the Libyan Sahara, on the passage of Palaearctic migrants in spring 1969 and 1970 and in part of autumn 1969. The ecological features and weather conditions in the study area are described. A map is given, and details of 70 species regularly observed are tabulated, with subsidiary notes on 57 other species only occasionally observed. A concentration of raptors, at a time when massed migrants were grounded, is described.Some species not normally considered trans‐Saharan migrants turned up in Sarir, including Robin, Blackbird and Greenfinch; also Black‐headed Bunting and Rose‐coloured Starling, which normally migrate between Europe and India.
THE MOULT OF THE WHITE‐BACKED AND RÜPPELL'S GRIFFON VULTURES GYPS AFRICANUS AND G. RUEPPELLII
Authors: Houston D. C. 
Published: April 2008

SummaryMoult is continuous throughout the life of the White‐backed Vulture and Rüppell's Griffon Vulture. Primary feather moult starts about 10 months after the bird leaves the nest, and the first feather to be shed is the innermost primary. From this position primary moult proceeds in an orderly sequence outwards towards the tip of the wing. Secondary feather replacement does not occur by the progression of moult waves, but by the irregular growth of feathers. It probably takes about 3 years of moult activity to complete the first feather replacement. Subsequent feather replacements occur by a slow but continuous process of feather replacement. Birds in adult plumage do show variations in the speed of moult, but this could not be related to breeding or body condition.
BREEDING OF THE WHITE‐BACKED AND RÜPPELL'S GRIFFON VULTURES, GYPS AFRICANUS AND G. RUEPPELLII
Authors: Houston D. C. 
Published: April 2008

SummaryThe breeding season of two species of griffon vultures are described. Rüppell's Griffon Vulture lays 2–3 months earlier than the White‐backed Griffon. Young birds were hand‐reared to determine their food requirements during growth; these estimates were combined with the food requirements of adult birds to make an estimate of the amount of food a parent bird needs to obtain when it is rearing young. The amount of food actually obtained by a group of birds was recorded from the size of the crops of birds returning to the breeding colony in the afternoon. The comparison of the estimates of the food obtained and the food required through the breeding season suggested that there may be a period during rearing when there was insufficient food available to satisfy the food requirements of both chick and adult. Chicks were found to have a very high survival rate and were probably receiving sufficient food. Presumably adult birds were not therefore receiving sufficient food, and the examination of a sample of adult birds for body condition through the breeding season showed a clear decline in their fat deposits. It was considered that in both species, breeding was timed so that the young left the nest at a period in the year when food conditions were good and the young birds could feed with little competition from adults. The parent birds therefore had to rear young during a season in the year when food conditions were not always adequate and they had to rely on utilising fat reserves. The food conditions for vultures during this study were probably favourable and during years of food shortage breeding may become impossible, or restricted to the most aggressive and dominant individuals.
AUTUMN 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 108 days and 93 nights in the period 13 August‐13 November in 1970 and 1971. Altitudes were recorded on nine days.Passerine movements to the E‐SSE from Puerto Rico and Hispaniola occurred on many nights. Their density was greatest between late September and mid‐November, especially when the easterly Trade Winds abated. Shorebirds and passerines moving SE, S and SW on a broad front approached from over the ocean intermittently throughout the period, with largest numbers from mid‐September to early November. Arrivals occurred at all hours of the day and night. Many were at altitudes of 3 to 6 km, including some believed to be passerines. Birds that flew high by day descended after sunset. Many continued southwards over or past Puerto Rico.The tracks of birds arriving from over the ocean were correlated with wind direction, but were rarely downwind. The variance in tracks was slightly greater on cloudy than on clear nights, but there was no evidence of serious disorientation in any situation. There was a negative correlation between the density of arrival from the north and the easterly component of the wind. This, together with evidence that the eastern edge of most passerine flights was near Puerto Rico, suggests the existence of lateral wind drift. The relationships of estimated headings to wind and to tracks also suggested that the birds were drifted, contrary to the situation in spring.The shorebirds and passerines arriving from the NW‐NE were concluding overwater flights of 2000–3000 km from SE Canada and the eastern U.S.A., often along clockwise‐curved routes. Some that continued to South America flew 4000 km or more non‐stop.
THE COMPOSITION AND BEHAVIOUR OF SOME MIXED‐SPECIES BIRD FLOCKS IN SARAWAK
Authors: Croxall J. P. 
Published: April 2008

SummaryMixed‐species flocks of birds feeding on insects were observed mainly in forest in Sarawak at a time of year when insect availability is known to be near its annual minimum. The approximate individual and specific composition of most flocks were noted. Twenty‐six species occurring in 25% of flocks were regarded as occasional members, 15 species occurring in 40% of flocks being classed as regular members.Recording species' feeding behaviour was the main priority and few observations of inter‐ and intra‐specific interactions within the flock, horizontal distribution or vertical stratification were made, although the last proved to be of potential significance. From the analysis of feeding behaviour two groups of species were distinguished. The larger group contained those usually having an exclusive common feeding pattern and showing very little overlap with the other such species. Fewer species used a wide range of feeding methods, all of which were shared with other species, but the least overlap was with other members of the same category.The observed composition of these flocks, in terms of regular members, might be interpreted as ensuring a low level of inter‐specific competition and it is suggested that the less specialized foragers may occur in the flocks by utilizing the ‘gaps’ between, and absences of, specialists.The possible advantages of membership of mixed‐species flocks are briefly considered and the likelihood of the selective advantage in any situation being the result of a balance of factors emphasized. In the apparent absence of regular potential predators the existence of these flocks is interpreted primarily as an adaptation for augmenting available insect food, particularly perhaps at critical times of year, by flushing insects as a result of the foraging activities of flock members. It is suggested that the varied responses of insects on being disturbed coupled with the different and fairly specialized feeding techniques of the birds could ensure benefit for all members of the flock.
THE FOOD OF RED GROUSE CHICKS LAGOPUS L. SCOTICUS
Authors: Savory C. J. 
Published: April 2008

SummaryThe diet of young Red Grouse was studied from the crop contents of 211 chicks caught on a moor in northeast Scotland. The food was more varied than that of adults, but shoot tips of heather usually formed at least 75% (by dry weight) of their diet, as in adults. Arthropods, particularly Diptera, were taken frequently by chicks up to three weeks old, but they formed less than 5% (by dry weight) of the diet then. The chicks ate more invertebrates when more were available. There was no evidence that chick survival was related to the abundance of invertebrates. The chicks ate heather containing more nitrogen and phosphorus than that eaten by adults at the same time of year.
THE ABILITY OF BARN OWLS TYTO ALBA TO DISCRIMINATE AND LOCALIZE AVIAN ALARM CALLS
Authors: Shalter Michael D. , Schleidt Wolfgang M. 
Published: April 2008

SummaryTen Barn Owls were tested in a sound‐room with recordings of various alarm calls and noise. The owls readily responded with head movements to the majority of stimuli and correctly oriented to their source. The seeet alarm call and the ‘warning’ call elicited the least responses, but they were properly localized by all owls which did respond. This suggests that rather than non‐localizability accounting for the fewer observed responses to the seeet and ‘warning’ calls, there is either something else in the quality of those sounds, or in the manner in which they are processed by the bird, which does not elicit responses to the degree that transient sounds with broad frequencies do. Selection in these predators for non‐responsiveness is suggested as a counter‐strategy to minimize futile energy expenditure in attacking, or otherwise responding to an alerted prey.An additional hypothesis, consistent with Darwin's antithesis principle, is proposed whereby intraspecific and interspecific selection, rather than predator selection for non‐localizability, has led to the evolution of seeet and mobbing calls.
A RADAR STUDY OF TERN MOVEMENTS ALONG THE COAST OF GHANA
Authors: Grimes L. G. 
Published: April 2008

SummaryDuring spring and autumn 1970 and 1971 the movements of terns off the coast of Ghana near Accra were studied by radar. In autumn, dense movements were recorded within 22 km of the coast both day and night from July to early December. Fluctuations in the magnitude of the movements suggest that the terns were on passage through the Gulf of Guinea. Simultaneous to these movements were roosting flights into shore roosts and both movements appeared independent.In contrast, no spring movements along the coastline were detected either by radar or visually from the land. Although small tern flocks probably moved westwards within 22 km of the coast, but outside their detectable radar range, the results suggest that the majority of terns return through the Gulf of Guinea by a different route from that taken in autumn.The difference between spring and autumn movements correlates well with the seasonal variation of the terns' food sources. In autumn, upwellings result in an abundant fish supply (sardines) in the surface waters close to land, whereas in spring, fish is abundant only well off shore such as at fronts (convergences) and upwellings (divergences) both of which have been located as far as 600 km from the coast.
FILTER‐FEEDING DUCKS OF THE KAFUE FLATS, ZAMBIA, 1971–1973
Authors: Douthwaite R. J. 
Published: April 2008

SummaryThe occurrence, chronology of breeding and wing‐moult, and feeding habits of seven commonly occurring species of filter‐feeding ducks on the Kafue Flats in Zambia are described, based on 20 aerial surveys over the central section of floodplain and intensive observations on the ground at Lochinvar National Park, between October 1970 and January 1974.At high flood levels ducks were almost restricted to areas heavily utilized by lechwe; this association persisted until the floodplain became dry, but during the dry season ducks were also found on vegetated lagoons. Five species—Dendrocygna bicolor, Dendrocygna viduata, Thalassornis leuconotus, Netta erythropthalma and Anas erythrorhyncha—were most abundant between June and September; a sixth—Anas punctata—was most abundant between December and March, while the seventh—Anas undulata—was probably resident. At times the numbers of D. bicolor, D. viduata and A. erythrorhyncha probably exceeded 25 000; those of N. erythropthalma reached 6500, but the numbers of T. leuconotus, A. punctata and A. undulata were much lower and at Lochinvar did not exceed 500.Small numbers of D. bicolor, N. erythropthalma, A. punctata and A. undulata nested on the floodplain in the vicinity of Lochinvar between March and July. All seven species completed their wing‐moult between April and October in the area; large numbers, particularly of A. erythrorhyncha and D. bicolor, were involved.At Lochinvar, A. punctata fed mainly on aquatic invertebrates; the remaining species fed largely on shed fruits and seeds. The most important food plants were a terrestrial herb, Ambrosia maritima (January–April), two aquatic herbs, Nymphaea capensis and Nymphoides indica (May–August), and two aquatic grasses, Echinochloa stagnina and Vossia cuspidata (September–December). The herbs grew where grassland had been suppressed by lechwe; fruits of the aquatic grasses were found where lechwe had removed the overlying mat of stems. Despite similarities in diet the ducks differed from each other in feeding behaviour and/or preferred habitat.Five other species of filter‐feeding ducks, Anas capensis, Anas smithii, Anas clypeata, Anas acuta and Anas querquedula, have been recorded from the Flats, but all are rare.