bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE WEIGHT OF NESTLING ROBINS
Authors: Lack David , Silva E. T. 
Published: April 2008

Summary.

Nestling Robins Erithacus rubecula were weighed once each day from hatching until leaving the nest. Such regular visits largely eliminated the fear and premature flight reactions normally found in young Robins in the later stages in the nest.
Nestling weight increases extremely rapidly from hatching until about day 8 or 9, when the nestling may weigh ten times what it did at hatching. After about day 9 the weight stays approximately constant until the young leave the nest.
There are extremely marked individual differences (up to 80%) in the weights of young of the same age under natural conditions. Members of the same brood sometimes differ much, and sometimes only very little, in weight.
Round Oxford in 1946 and 1947 size of brood appeared to have no influence on the weight of the individual nestlings. However, it is possible that both years provided unusually favourable conditions of feeding for young Robins.
In 1947 the young in the two earliest broods to hatch died much below weight after a few days, apparently because caterpillars had not yet hatched in sufficient numbers to provide enough food for them.
The secondary coverts normally split open on day 6‐5, the primaries on day 7‐5. This happens irrespective of the body‐weight of the nestling. The nestling period also seems independent of body‐weight.
There were a few late developers, in which the wing feathers split open one or two days late. These individuals were at first low in weight, but continued to put on weight for one or two days after the age at which most nestlings had stopped.
The feeding visits of parent Robins to nestlings 7–14 days old varied from 3 to 33 visits per hour, averaging 13‐8 per hour. Broods of large size appeared to be visited rather more often than broods of small size, but the feeding rate did not increase proportionately to the greater number of young.
Reactions to predators near the nest are described.
The young can defaecate up to 7 % of the body‐weight. In the later stages in the nest, fsecal pellets were removed at an average rate of 0.8 per nestling per hour.
THE BIRDS OF THE COCOS‐KEELING ISLANDS (INDIAN OCEAN)
Authors: Gibson‐Hill C.A. 
Published: April 2008

Summary.The birds of the Cocos‐Keeling Islands, in the Indian Ocean, are discussed in the light of specimens and data collected during a stay of eleven months in 1941. Seventeen species were found to be breeding. One of these was an indigenous land bird, four were land birds known to have been introduced, and the remainder were sea birds mostly confined to North Keeling. During this period examples of seventeen species of strays or visitors were taken, of which ten probably occur regularly though in small numbers, while the other seven are true vagrants. Eight of these birds have not so far been recorded from Christmas Island.Eleven birds listed from the islands by previous visitors were not present in 1941. Two of these were introduced but have failed to maintain themselves, and one, Egrctta garzetta nigripes, seems to be an occasional vagrant. The remaining eight records are all unsatisfactory.
THE BREEDING OF A PARADISE FLYCATCHER
Authors: Moreau. R. E. 
Published: April 2008

Summary.1. At Amani, Tanganyika Territory, the Paradise Flycatchers use the softest moss for their nests and make them durable by oversewing the rim with cobweb. Sites are on the forest edge nearly always over water. Theree hours of observation were made at three nests in spells of about eight hours at a time.2. On the whole the males and females shared the care of the eggs and the young about equally, but there were wide differences in this respect from day to day3. The eggs were covered for over 90% of the observed time, and a high proportion of spells “on” were terminated by thc mate's arriving to take over. Duration of individual spells “on” varied up to two hours, but the favourite duration (nearly half of all the spells) was about 30–40 minutes. This applied both to spells “on” terminated by the initiative of the sitting bird and to those terminated by the arrival of the mate. The possibility suggests itself that an internal rhythm was operating, irrespective of whether a bird was on or off the nest. Nevertheless, out of 39 occasions (all short) when the eggs were uncovered through the sitter's departure without relief, the same bird returned on 18, which suggests that when off the nest both parents “keep an eye on it” and react to the situation “nest uncovered”.4. Brooding of the young amounted at first to nearly the same high percentage of time as the brooding o f the rggs, but was in much shorter spells. It stopped abruptly about the fifth day. others followed a parent.5. Each nestling of a brood of two in a nest received more food (largely butterflies) than each in two broods of three, 2.6‐5.4 feeds per hour compared with 14‐2.5 and 1.3‐1.8.6. Some of the young that wcre seen to fly left the nest in the absence of the parents, All left between dawn and noon. Nestling period about 11 days irrespective of the amount of food received.
THE DISTRACTION BEHAVIOUR OF THE ARCTIC SKUA
Authors: Williamson Kenneth 
Published: April 2008

Summary.Distraction displays of the Arctic Skua Stercorarius parasiticus were studied in the Faeroe Islands in colonial nesters and a solitary pair. There are aggressive and passive forms.The aggressive flight against human intruders is common throughout the nesting cycle in the colony, but absent from the behaviour of solitary pairs. It is suggested that its development is correlated with an internal rhythm which requires a certain level of mutual stimulation not attainable by solitary or widely‐scattered pairs. A highly formalized version of the attacking flight was employed against a sheep, in which the pair showed a marked tendency to coordinate their movements.The lure display when eggs are fresh is markedly different from that employed nearer the hatching‐period and afterwards. A courtship posture appears as a substitute activity in the early period, but only in the presence of the mate.In the solitary pair development of the normal lure display was gradual, reaching its peak towards the hatching‐period: there is a marked tendency for the pair to perform together, deriving mutual stimulation. It is suggested that this factor is important in the colony, where several perform together in scattered groups, in ensuring the earlier development (and therefore increased survival value) of the lure display. The birds' movements emphasize contrasts in the plumage coloration, and therefore the pattern may have greater biological advantage for colonies of predominantly light‐phase birds in areas of fox predation.The various patterns are described, and also variations incorporating false‐brooding and drinking motions. The main components of the patterns are probably derived from the primitive food‐begging of the chick, and elaborated with actions from courtship display.
THE ORIGIN OF STOMACH OIL IN THE PETRELS, WITH COMPARATIVE OBSERVATIONS ON THE AVIAN PROVENTRICULUS
Authors: Matthews L. Harrison 
Published: April 2008

Summary.The anatomy and histology of the proventriculus in several species of petrels were examined and compared with the conditions in other birds.The proventriculus in petrels is comparatively very large and its mucosa is raised into longitudinal ridges; it thus has a much greater surface area than in other birds. The presence of lipoids other than triglycerides concentrated in large quantities, particularly in the outer parts of the epithelial cells of the proventricular glands of petrels, is demonstrated. Lipoids in the corresponding cells in other birds are minute in quantity.The probability that these lipoids represent the stomach oil, or its precursor, immediately before secretion, is discussed and compared with other theories about the origin of the oil. The observations provide strong evidence, but not absolute proof, that the oil originates in the cells of the proventricular glands.Suggestions about the possible function of petrel stomach oil are discussed. The oil may supplement the secretion of the preen gland; it may be an excreted by‐product of the metabolism of excessively fat foods; or it may play an important part in water metabolism, especially in the nestling. Without further work, none of these theories can be upheld or refuted, and it is possible that all are partly correct, for they are not mutually exclusive.Many petrels shoot stomach oil from the beak when they are disturbed. The possible origin of this habit from the escape reaction, found in many birds, of vomiting up the stomach contents when alarmed, is pointed out.
THE BIOLOGY OF THE MOURNING CHAT IN WINTER QUARTERS
Authors: Hartley. P. H. T. 
Published: April 2008

Summary.Mourning Chats (Enanthe lugens in the Helwan area in Lower Egypt winter along the lower spurs of the mountains. Each bird occupies a separate territory from which it excludes other Mourning Chats, and wherein it sings.“Winter” song is most energetic in the months of July to October; at this season the main singing hours are in the early morning and early evening. In the period November to February song is less frequent, and is most often heard in the late afternoon.In the hot weather of the autumn the birds select perches in shade during the mid‐day hours.Evidence is advanced that there is a measure of interspecific territorial competition between Mourning Chats, Hooded Chats (Enanthe monacha and White‐tailed Chats (Enanthe leucopyga. The possible relevance of this interspecific territorial practice to the hypothesis of the “food value” of territory is discussed.
A CONTRIBUTION TO THE ORNITHOLOGY OF ST. HELENA, AND OTHER NOTES FROM A SEA‐VOYAGE.
Authors: Benson C. W. 
Published: April 2008

Summary.

An account is given of the ornithology of St. Helena, every species at all definitely recorded therefrom being mentioned, some for the first time.
Details of the breeding of Anous stolidus and Megalopterus mimitus are given and the breeding‐seasons of other sea‐birds inhabiting the island are also assessed, but further data are needed. In particular, the status of Sula leueogastra and of another species, cither S. sula or S. dactylatra, require further investigation.
The starling now so common seems to be Acridotheres tristis, not Eulabes religiosa.
Other points requiring further investigation are:

Fossil bones should be sought of the avifauna, now extinct, which may have inhabited the original dense forests, destroyed by 1810. (A species of rail may have occurred.)
The possibility of Charadrius pecuarius pecuarius having arrived on the island, and becoming differentiated into the very distinct C. p. sanctae‐helenae, the only indigenous land‐bird still surviving, within a period of about 300 years.
The validity of Estrilda astrild sanctae‐helenae, and date of introduction of the species.

Other birds of interest seen during the same voyage as St. Helena was visited are mentioned.
QUELQUES OBSERVATIONS SUR LA NIDIFICATION DES STERNES DANS LES EAUX DE MADAGASCAR.
Authors: Milon. Lt.‐Col. Ph. 
Published: April 2008

Résumé.Des observations faites à Madagascar dc 1946 à 1948 sur la présence et la nidification des sternes sont rapportées, avec la saison du début de la ponte:—Dans un îlot des Glorieusts, Sterna fuscata nidific.La liste des oiseaux marins observés sur l'île Europa est dressee.Au Nord de l'îile; trois espèces.Au Sud de l'îile; quatre espèces.A l'Est de l'île est signalée un centre de nidification, d'après des déclarations. de pêcheurs.
FIELD NOTES ON THE BIRDS OF BEAR ISLAND.
Authors: Duffey Eric , Sergeant. David E. 
Published: April 2008

Summary.

A brief account is given of the topography of Bear Island and of previous ornithological work.
Thirty‐three days were spent on the island, the greater part of which was covered during a census of the bird‐life. A short ecological account is given of the breeding birds.
The effect on the bird‐life of recent climatic trends in the arctic is discussed.
Evidence is given for non‐breeding in a number of species.
A systematic list of 28 species includes field notes.
A STUDY OF THE AFRICAN HOOPOE*.
Authors: Skead. C. J. 
Published: April 2008

Summary.1. Hoopoes scarce and silent from Jan. to mid‐March.2. Small parties then foregather. From mid‐April there is much jostling and pooping until breeding starts in August.3. Male courts female by giving her tit‐bits of food.4. Birds maintain a feeding territory in breeding season, and are restless, rather than migratory, thereafter.5. Female remains in nest from commencement of egg‐laying and is fed there by the male; but she does emerge to feed herself too.6. Incubation period about 17 days.7. Male continues to feed young after the hatch.8. Female remains in nest‐hole for about seven days, taking food from the male at entrance to feed young. Also emerges to feed herself at times.9. After the seventh day both birds share chick‐feeding, the young coming to the entrance to take food on the eleventh day.10. Nestling periods vary from 26 to 32 days. Chicks of the same brood do not always emerge from the nest of the same day. Those remaining are still fed by the adults.11. Both adults feed young in post‐nestling period.12. The species is double‐ and possibly treble‐brooded.13. Nest sanitation primitive.14. Three individuals recorded as having taken part in a nesting attempt.15. The well‐known “poop” call is made by the male only. Other calls described.
OBSERVATIONS ON THE BIRDS OF PICO, AZORES.
Authors: Marler By Peter , Boatman Derrick J. 
Published: April 2008

SUMMARY.1. A visit was made to the island of Pico, in the Azores, in the spring of 1949.2. The relative frequency of the bird species in the three main vegetation zones is estimated from the data obtained fron a series of transects and the results are discussed.3. Ecological‐niche expansion is seen to occur in Motacilla cinerea, Regulus regulus, Sylvia atrieapUla and Leucopolius alexandrinus.4. Song and call‐notes differ from the corresponding British birds in Fringitta coelebs, Regulus regulus, Sylvia atricapiUa and Turdus merula, and the two former are also thought to exhibit voice‐range extension, due to the absence of some closely related species.5. An annotated list of all the species seen is given, with notes on the feeding habits, etc.
MELANIC BLACKCAPS IN THE ATLANTIC ISLANDS.
Authors: Southern. By H. N. 
Published: April 2008

SUMMARY.1. The blackcap Sylvia atricapilkz is resident on the Cape Verdes, the Azores, Madeira and the Canaries, and birds of the last two have been separated as a local endemic race, S. a. obscura, distinguished by darker plumage.2. On Madeira and the Canaries the blackcap occupies mainly the cultivated and settled zones, so that their numbers must have greatly expanded since the islands were colonized.3. A melanic variety occurs probably on all of the Azorean islands and on Madeira. On the Canaries it has occurred only in the Great Crater of Palma, but recent investigation suggests that it is now uncommon here, if not extinct. Its frequency in the other island groups is about 2%.4. Data from the literature show that this variety interbreeds with normal birds and probably behaves as a single‐factor recessive.5. The difference between the Azores, where the melanic bird occurs on all the islands, and the Canaries, where it is restricted to one part of one island, is probably due to different selection pressures, but there is some evidence that Canarian and Madeiran populations may be in a somewhat unstable condition, perhaps partly because of their recent expansion.
THE “SPECTACLED” FORM OF THE SHOEMAKER PROCELLARIA AEQUINOCTIALIS IN THE TRISTAN DA CUNHA GROUP.
Authors: Rowan A. N. , Elliott H. F. I. , Rowan M. K. 
Published: April 2008

SUMMARY.The Shoemaker Procellaria aequinoctialis was discovered breeding at Inaccessible Island, Tristan da Cunha, in the early 1920's by Partridge. The warrens were investigated by Lawrence in 1943, and again by the authors in 1949 and 1950. The present paper is believed to be the first published record of this Shoemaker breeding‐station, where the birds have now been found present in the months of May, June, September and November and to be exclusively of conspicillata type. Their nesting habits are unlike those of the species elsewhere and they are smaller birds. They are regarded not as a colour‐phase but as a subspecies, P. ae. conspicillata.
LIFE HISTORY OF LONGUEMARE'S HERMIT HUMMINGBIRD.
Authors: Skutch By Alexander F. 
Published: April 2008

SUMMARY

Observations on Longuemare's Hermit were made in Guatemala, Honduras and Costa Rica.
Males gather in courtship assemblies usually amidst dense second‐growth. Each has a favourite perch, where he performs through the day.
They sing through most of the year, except from the height of the dry season in February until the rains start in April, and again at the height of the wet season in September and October.
The courtship display, an intricate aerial dance above the perching female, is described.
The downy nest is built by the female (largely on the wing) beneath the tapering tip of a palm‐frond, or other leaf, 3 to 6 feet above the ground. Cobweb binds the nest to the leaf.
The normal clutch is two eggs, laid at about 6 a.m. on alternate or sometimes consecutive days.
Occupied nests were found in every month except February and March, September and October (when the males are not in song).
The female alone incubates, sitting with breast toward supporting leaf, head thrown far back. To leave, she flies upward and backward; to return, she flies directly down into the pocket of the nest.
Incubation period 15–16 days; nestling period 20–21.
On the day of hatching, the blind nestlings orient themselves with heads towards the leaf, and so remain until they fly. The female feeds them while she hovers–as though visiting a flower–reaching over their backs and regurgitating into their throats.
FIELD STUDIES ON THE FULMAR FULMARUS GLACIALIS.
Authors: Duffey Eric 
Published: April 2008

SUMMARY1. An account is given of observations on three pairs of marked Fulmars. The young were brooded for very irregular periods, and in one pair the female took the greater share.2. In the first two to three weeks of the chick's life it does not recognize its parents. and treats them as intruders to be repelled. The parent has a characteristic method of approach with which the chick gradually becomes familiar.3. A small but distinct territory around the nest‐site is defended by the chick and parent birds.4. Feeding takes place at any time during the day, but the chick is probably not fed daily during the first week or two. During its first two to three weeks the chick does not show any interest in its parent and has to be stimulated before feeding takes place. When older, the chick is able to recognize its parents and also initiates the feeding process.5. In four case it was shown that the chick was fed on semi‐digested food material, not oil.
A STUDY OF THE HADEDAH IBIS HAGEDASHIA H. HAGEDASH.
Authors: Skead C. J. 
Published: April 2008

SUMMARY1. Biology of the Hadedah in Cape Province is described with special reference to roosting and flocking. The birds are not strongly territorial, and at all times are amicable.2. Main breeding season October‐November, with occasional double broods.3. Incubation period 26 days, both parents sharing incubation.4. Nestling period about 33 days, both parents feeding young by regurgitation.5. Mortality of nestlings, by falling out of nests, is remarkably high.6. Food consists of insects, millipedes and earthworms.
REGIONAL VARIATION IN THE DISTRACTION DISPLAYS OF THE OYSTER‐CATCHER.
Authors: Williamson. Kenneth 
Published: April 2008

Summary.The Oyster‐catcher Haematopus astralegus populations of western Europe (Holland, South Britain, Fair Isle, Unst and Faeroe Islands) differ very little morphologicallv, but show interesting variations in their distraction displays.These displays, comprising (1) aggressive flight, (2) a furtive run, (3) false‐brooding, (4) pseudo‐sleeping, and (5) lure display, are described, with comments on their regional importance. Aggressive flight, false‐brooding and lure display are more strongly developed in Faeroe than elsewhere. At Fair Isle (and to a less extent at Unst) displacement “ butterfly‐flight” replaces lure display.It is shown that the lure display has evolved as a terrestrial modification of displacement “ butterfly‐flight”, which has proceeded furthest in the Faeroe population, hardly at all in the more southerly populations, and to an intermediate degree among the birds of Unst.The Oyster‐catcher's extension to the Faeroe Islands—probably from the British area, in Comparatively recent times—involved colonization of an atypical moorland habitat. The distraction displays appear to have been perfected in the absence of terrestrial predators other than men and dogs, which have been present for about 1000 years.The remarkable development of these display patterns is probably due to hereditan differences, affecting ethological attributes, which have arisen between the Faeroe and the more southerly populations. It is suggested that their evolution has been stimulated by the psychological effect of frequent disturbance of the brooding urge by man, during the attempt to colonize a new and unsympathetic environment.
THE GREATER SHEARWATER PUFFINUS GRAVIS AT‘ ITS BREEDING GROUNDS.
Authors: Rowan. M. K. 
Published: April 2008

Summary.

An account is given of the breeding cycle of the Greater Shearwater, with speciat reference to the colony (estimated at 4,000,000 breeding birds) at Nightingale Island in the Tristan da Cunha group.
The birds arrive at the breeding grounds during late August and September. There is a brief laying season during the second week of November and the chicks hatch early in January. In April the adults desert their young, when they are full–grown but still in down. Fully feathered juveniles are found at the beginning of May and start flying towards the end of the first week of May. As far as is known the juveniles have all left the breeding grounds by early June.
Special points of interest relating to the breeding cycle are:.‐(a) The presence of Greater Sheanvaters at the breeding grounds in large numbers at least one–and–a–half months in advance of the laying season. (b) The overcrowding of the breeding grounds at Nightingale. (c) The courtship ceremonies. (d) A strongly developed diurnal habit during the breeding season, although the birds are most active after 4 p.m. (local time) and at night. (e) The presence of large numbers of juveniles at the breeding grounds during May. (f) The apparent absence of adults from their burrows. from mid–April onwards.
The occurrence of the Greater Sheanvater at the north–easterly limits of its range at the time breeding IS beginning suggests that a proportion of the population fails to breed each year, and that the main return from the north takes place in mid–ocean, and down the west side of the Atlantic, mainly in August.
Flight and locomotion are described.
Data collected on the exploitation of this species by the Tristan islanders show that the annual depletions are not more than l% of the estimated Shearwater population at Nightingale.
THE WINTER AVIFAUNA OF ARCTIC LAPLAND.
Authors: Snow. D. W. 
Published: April 2008

Summary.

The winter environment of Arctic Lapland is described, in so far as it affects the birds.
The wintering birds are listed, together with their main foods, and the adaptations shown by them are discussed, a distincfion being drawn between “ pre–adaptations” and “specific adaptations”.
The effect of man on the winter avifauna is estimated.