bluuebunny/crossref_metadata_2025 huggingface dataset:
TERRITORY IN THE BLACKBIRD TURDUS MERULA.
Authors: Snow D. W.
Published: April 2008

The territorial behaviour of the Blackbird has been studied in a garden habitat holding 11–17 pairs. The average size of territories has been from 0.4 to 0.6 acres.

Old males maintain their territories all the year round, and their mates usually stay with them. Young males begin to take up territories in their first autumn, but most do not become well established until February or March. Young females show preferences for particular areas, which they defend against other females, and may associate with the owning males, but the definitive pairs for the breeding season are not usually formed until early spring.

There are frequent minor changes in territories during the breeding season, and in addition territorial activity fluctuates with each nest‐cycle, defence being strictest when a new nest is being started.

It appears to be essential for a male to have a territory in order to obtain a mate. Spring song is nearly all from young males which are claiming a territory; it has no essential function in pair‐formation. Once a mate is acquired, defence of a territory is to some extent modified so as to include defence of the mate.

Territory is not used principally as a source of food, for either adults or young. Its possible functions are discussed.
THE TERRITORY OF THE WHEATEAR OENANTHE OENANTHE.
Authors: Conder P. J.
Published: April 2008

Migrant Wheatears held small territories while resting on Skokholm. Resident males usually arrived before the females and occupied territories in which they were joined by their mates. Wheatears pair for life and usually occupy the same territory. Territories averaged about four acres, but less in years of high population. Territory may act as a limiting factor to population size although it never did so in the years of this study. The territories supplied sufficient, if not more than sufficient, food for adults and nestlings.

Territory taken up in spring was thought to be of first importance in forming the pair, in maintaining the bond between the pair and in establishing a breeding area. That it also comprised a feeding area was thought to be of secondary importance.
FOOD, FEEDING HABITS AND TERRITORY OF THE ROCK PIPIT ANTHUS SPINOLETTA.
Authors: Gibb John
Published: April 2008

This paper describes the food and ecology of a few Rock Pipits, mainly in Cornwall in winter.

Rock Pipits prefer exposed to sheltered coasts. Their average density in favourable habitats was ca. 8 pairs per mile of coast.

Rock Pipits fed chiefly on the shore in winter and just inland in summer.

Rock Pipits fed more intently in mid‐winter than in spring and autumn; and, at any one season, most intently when food was scarce. Also, they fed more intently in the afternoon than in the morning in mid‐winter (correlated with the long winter nights), and vice versa in spring and autumn. Whenever food was scarce they fed hard all day.

There were four common littoral foods in winter:the periwinkle Littorina neritoides, chironomid midge larvae, dipteran larvae (Coelopa spp.), and isopods (Idotea spp.). Amphipod hoppers (Talitridae) were sometimes an important food in late summer. The availability of these foods and the predation of the Rock Pipit upon them are described; rates of feeding and defaecation were measured.

The total food consumption of one Rock Pipit was estimated for a number of days in December, 1950 and 1951. The dry weight of food eaten daily averaged ca. 26 gms. when periwinkles, and ca. 12‐5 gms. when chironomid larvae were the main food. The dry weights of organic material consumed daily were ca. 6 gms. (calorific value 30 Calories) in December 1950 and ca. 4 gms. in December 1951. When periwinkles were the main food the bird digested only 40% of the organic intake; hence its energy intake was ca. 12 Cals. daily. These results are compared with similar data for three other bird species.

No other bird species seriously competed with the Rock Pipit for food.

Intra‐ and inter‐specific fighting (chiefly for food), and the Rock Pipit's response to predators are described.

Rock Pipits are intensely territorial; they defend individual territories in winter. The possible functions of territory are discussed:winter territories are primarily concerned with food.

Conclusions: (i) since winter territories were just, but only just, big enough to provide sufficient food, their size was probably determined by their food resources; (ii) since Rock Pipits were sometimes apparently short of food and competed for it in winter, food shortage could limit their density.
NEW OR UNUSUAL RECORDS FROM NORTHERN RHODESIA.
Authors: Benson C. W.
Published: April 2008

A number of forms are added to the Northern Rhodesian list. Others are also mentioned, of which there have been few previous records from the territory, or which represent extensions of range therein. Detailed notes are given on certain Sarothrura spp. The nesting of Neocichla gutturalis is described for the first time.
THE SPECIES OF APUS.
Authors: Lack David
Published: April 2008

The correct determination of the species of Apus is difficult. Their extreme adaptation to aerial life allows for few trivial or incidental differences. Some species look much alike and some conspecific races look very unlike. In several instances two conspecific races look more different from each other than one of them does from another species.

Forms of the same species tend to be darker in areas of higher rainfall and smaller at lower latitudes, the differences in some cases being so striking that true affinities were not previously recognized.

The instances of strong resemblance between races of different species are due partly to all the species of Apus possessing a similar basic colour pattern and partly to convergent adaptation.

The relative length of the first and second primaries provides a useful taxonomic character, the second primary being longer in the forms with strongly forked tails.

The winter ranges of the European species are reviewed.

The following changes in specific status from the list by Peters (1940) are advocated. The more tentative proposals are indicated by (t).
THE BREEDING OF THE GREAT‐WINGED PETREL PTERODROMA MACROPTERA
Authors: Warham John
Published: April 2008

Observations on the behaviour of the winter‐breedingPterodroma macropterawere made during two visits to Eclipse Island, Western Australia, in 1954.

Calls, flight, courtship behaviour and feeding of the young are described.

Burrowing and pairing up takes place in March, egg laying towards the end of May, hatching in July and the young fly in November.

One incubation period was about 53 days and two fledging periods 128 and 134 days.

Although the breeding ground appears to be deserted from September onwards this is due to the disappearance of unemployed birds. The chicks are fed about once weekly and there is no starvation period.

The young birds have few enemies apart from skinks and they do not normally spit oil.
THE VOICE OF THE CHAFFINCH AND ITS FUNCTION AS A LANGUAGE
Authors: Marler P.
Published: April 2008

The voice of the Chaffinch has been studied by making recordings and analysing them on a sonograph. The contexts in which each call is given are described.

The 14 basic calls are flight, social, aggressive and injury calls, three alarm calls, subsong and song, three courtship calls and the begging calls of nestlings and fledglings. With their variations they give 21 different signals.

The ontogeny of certain calls and the occurrence of intermediate forms suggest how voice may have evolved in the Chaffinch. A hypothetical ancestral type agrees with certain Cardueline finches, implying a closer relationship than recent anatomical studies suggest.

Unlike many displays, calls often occur without an obvious conflict in motivation.

The voice of Chaffinches reared in isolation is usually normal, but song is usually abnormal and in nature is perfected by learning from other birds. The social call is sometimes abnormal and may sometimes be modified by learning under natural conditions.

The communicatory function of voice has been assessed by studying the responses of other Chaffinches to it. By comparison with other contexts in which the same response occurs, a list of “information received” is constructed. The recipient respondsas thoughthis has been received.

Four general types of information are involved, social and environmental, identifying and locating.

Inter‐specific communication occurs with other woodland Passerines, especially through alarm calls. The alarm calls are of a type difficult for predators to locate. Different families have independently evolved the same type of call for this purpose. Other alarm calls of many species, used to draw attention to the position of a predator, are adapted to be easy to locate.

The general structure of many calls can be understood in terms of the need to facilitate or hinder location of the calling bird.

There are other factors governing the form of voice, especially the need to differ from the calls of other sympatric species. This only applies to calls communicating certain types of information. Some of those exempt from this need for divergence may be especially useful in phylogenetic study.

The two main types of response to voice are related to the different types of information conveyed by the calls. Mechanisms of response are discussed, and the differences between the languages of the Chaffinch and of man.
A COMPARATIVE STUDY OF THE CALLS OF EMBERIZA SPP. (BUNTINGS).
Authors: Andrew R. J.
Published: April 2008

Bunting calls in general express the tendencies to fly, to behave sexually, to behave aggressively, or to give fear responses. (Close begging‐calls probably express a tendency to feed.)

 Bunting social calls express weak fear aroused by being alone, and as a result are often given by solitary males before they sing.

 A primitive “seeoo” call expressing fear has probably evolved into (a) a call easy to locate that expresses weak fear and serves as a social call, and (A) a call difficult to locate that expresses strong fear and serves as an alarm‐call.

 The “tit”‐type flight‐call, which both in its normal form and in its probable variant, the distant begging‐call, shares with social calls the function of keeping birds in touch with each other, is also easily located.

 When there are simultaneous tendencies to give two different calls, the form of one may be imposed on the other (e.g. a normally repeated flight‐call may be given singly, or an alarm‐call be rapidly repeated in the form of a soliciting call).
A CONTRIBUTION TO THE ORNITHOLOGY OF THE TRISTAN DA CUNHA GROUP.
Authors: Elliott H. F. I.
Published: April 2008

Based on work during residence from January 1950 to October 1952, a revised check‐list is presented for the Tristan Group, together with field and taxonomic notes on the individual species. Only two subspecies of birds, other forms of which survive elsewhere in the group, are known to have become extinct during the century and a half of human settlement.
THE DISPLAYS AND NESTS OF THREE FOREST HUMMINGBIRDS OF BRITISH GUIANA
Authors: Davis T. A. W.
Published: April 2008

Field notes are given on the displays and nesting ofPhaethornis superciliosus, P. ruber, andTopaza pella, and are compared and discussed.
NOTES ON AUTUMN MIGRATION IN THE MIDDLE EAST
Authors: Bourne W. R. P.
Published: April 2008

Notes were made on autumn migrants in Jordan and Iraq in the late autumn of 1956. Three movements were distinguished, a trans‐desert passage of passerines and water birds, local movements of larks and sand‐grouse, and incursions of northerly winter visitors. Some factors affecting the movements are discussed.
HYBRIDIZATION IN SOME INDIAN BULBULS PYCNONOTUS CAFER X P. LEUCOGENYS
Authors: Sibley Charles G. , Short Lester L.
Published: April 2008

Hybrids between the two bulbuls, Pycnonotus cafer and P. leucogenys, are described and analysed.

Significant correlations between colour pattern and size in the hybrids are demonstrated.

The two parental species are widely sympatric. Hybrids rarely occur except where one species is uncommon.

It is probable that the incidence of hybridization is decreasing and that the isolating mechanisms between the two species are being reinforced.
ANTING MOVEMENTS AND THEIR RELATIONSHIP TO CERTAIN OTHER BEHAVIOUR PATTERNS
Authors: Simmons K. E. L.
Published: April 2008

The anting movements of nine passerine species were studied in captivity and in the wild. The birds applied acid‐spraying Formicine ants (genera Lasius and Formica) to the plumage with the bill, with one wing extended and the tail brought round and often pressed against the wing.

Only the Magpie deliberately applied the ants both to the tail and wing. In the Song Thrush, Blackbird, Starling, Western White‐eye and Blue Tit, application was to the wing‐tip alone, while the Pekin Robin, Black‐chinned Yuhina and old‐world Robin treated the wing‐tip and also, incidentally, that part of the tail held close to it. The direct result of this behaviour is the anointing of the wing‐tip with formic acid, the posturing of the tail facilitating this by making the wing‐tip rigid.

Anting is, apparently, one of the “feather maintenance” activities (preening, oiling, bathing, dusting, sunning) and, in the Pekin Robin and Song Thrush at least, the movements used in applying preen‐oil to the wing‐tip are very similar to, and probably homologous with the anting movements.

Formic‐acid possibly supplements the natural preen‐oil but the exact function of the anointing remains to be discovered.
THE BURROW‐EXCAVATION PHASE IN THE BREEDING CYCLE OF THE SAND MARTIN RIPARIA RIPARIA
Authors: Hickling R. A. O.
Published: April 2008

Observations were carried out at a Sand Martin colony in a working sand‐pit, where fresh burrows have to be dug each year. Sand Martins arrive at the breeding pit from migration unpaired, and their social organization is then at its lowest. Burrow excavation occurs only as the climax to a form of group display. Digging is communal in character, and the number of holes dug is roughly equal to the number of individual birds present. The mounting excitement and mutual stimulation of the display period induces a climax at which the birds begin to build nests and lay. This period of display produces close synchronization which seems to be a necessary condition for the communal behaviour of the birds during the rest of the breeding cycle.
THE BIRDS OF THE PITCAIRN ISLANDS, CENTRAL SOUTH PACIFIC OCEAN
Authors: WILLIAMS G. R.
Published: April 2008

A first species list is presented for the Pitcairn Islands group in the Central South Pacific Ocean. Field notes on species were made during a visit in late 1956. Of the 28 forms listed, Henderson Island has 17, Oeno 13, Ducie 10 and Pitcairn 6. The avifauna is predominantly oceanic and migrant, the few lar d‐birds having Polynesian affinities, most closely allied to those of the Austral Islands and the Tuamotu group. Two species have been introduced–both to Pitcairn Island– and one of these is now extinct. No extinction of native species has ever been recorded.
THE BREEDING OF SOME S.W. ECUADORIAN BIRDS
Authors: MARCHANT S.
Published: April 2008

The breeding of about 40 species of birds in the Ancon district of the Guayas Province of S.W. Ecuador is described. The information is based on the records of about 2000 nests observed during 1955–1958. About half the species are birds which range over much of Central and South America and whose breeding has been previously described, though usually casually. For these my own remarks are confined to new information, doubtful points and confirmatory details. The rest are species more or less confined to the west coast of South America between Ecuador and Chile, and for which there is either little or no breeding information in the literature. These are treated under headings of nest site, nest, eggs, clutch‐size, laying, incubation, nestling period, breeding success and season, with general remarks where appropriate. For most species, closely determined incubation and nestling periods arc given, and for some, quantitative data on clutch‐size and breeding success are available. In some species differences have been found for annual mean clutch‐size, mean clutch‐size laid before and after rain, annual breeding success and fledging success, doubtless due to pronounced climatic variation from year to year which either has a direct effect or influences predation.

These matters are discussed generally in the introduction, with particular mention of 10‐day incubation periods, the rapid nesting cycle of several finches, precociousness of their young, and comparison of breeding success with that of European species, as well as the peculiar ecological variations of the district and changes in predators.

In the sequel the statistical aspect of my data is analysed by Dr. Monte Lloyd and I have followed this with somea posterioriremarks.
SOCIAL BEHAVIOUR IN THE PARTRIDGE PERDIX PERDIX
Authors: Jenkins David
Published: April 2008

1. Some aspects of Partridge behaviour (see Contents) are described, and, using defined criteria, activities are divided into: (a) those resulting primarily from intraspecific interaction (agonistic behaviour); (6) those occurring independently of interaction, mainly feeding and courting. Some activities, notably preening and resting, were found to occur under both heads, and were classified with group (a) because they were thought sometimes to be displacement activities. An index is described to measure the proportion of time spent feeding and courting, and hence, inversely, the amount of interaction, under different circumstances. The behaviour of birds in different environments is compared.

2. It is possible to correlate the degree of interaction with population density and ground cover in different fields. There was less interaction when the birds were living at low density, or where the ground cover prevented them seeing each other. In good cover, and also in low–density areas, the size of home ranges was relatively small and they did not overlap; in areas where density was high and ground cover poor, home ranges were larger and overlapped. Birds in good cover interacted little with each other, even at a high population density; but others, living at similar population densities, interacted continuously if the cover was poor. Intermediate situations are also described.

3. The possible importance of agonistic behaviour with regard to dispersion and population control is discussed briefly.

4. A correlation was observed between chick mortality in two summers and the interaction observed among adults during the previous winters.
THE BLACK NODDYANOUS TENUIROSTRISON ASCENSION ISLAND PART 1. GENERAL BIOLOGY
Authors: Ashmole N. P.
Published: April 2008

Several colonies of Black Noddies Anous tenuirostris on Boatswain Bird Island, off Ascension, were studied for almost a year, including the whole of one breeding period and the start of another. Between the breeding periods the noddies roosted on their ledges in the breeding colonies, so observations could be made throughout the year. The single eggs were laid on small ledges, usually on steep cliffs; nest material was scarce, and some eggs fell off the ledges during incubation, but many young were reared successfully in the first part of the breeding period. However, food shortage resulted in slow growth and eventual death of all the chicks hatched later in the season, and the weights of adults were also low at this time.

It was shown that individual noddies sometimes bred at intervals of much less than a year, and that breeding occurs in different months in different years; however, the interval between the start of breeding in 1958 and 1959 was almost a year, and i, t is suggested that this was unusual, and a result of the food shortage late in 1958.

The moult of the noddies was studied in detail; it was found that individuals were either involved in breeding activities, or were in process of moult, almost all the time, while a few birds started breeding well before they had finished their moult.

The discussion concerns the reason for the rough synchrony in breeding among the Black Noddies on Ascension, and the relation between breeding and moult cycles in the population.
THE NEST‐BUILDING BEHAVIOUR OF THE MAGPIE GOOSE ANSERANAS SEMIPALMATA
Authors: Davies S. J. J. F.
Published: April 2008

Magpie Geese Anseranas semipalmata build substantial nests of vegetation in the extensive Eleocharis/Oryza swamps of Northern Australia. Building activity begins some two months before the eggs are laid, and a large number of stages and preliminary nests are built before the true nest. It is thought that males generally initiate and take a large share in nest‐building. Experimental evidence suggests that building activity is greatly intensified in wet weather.

Field observations show that the nests are always placed in swamps, the vegetation of which lies within a specific range of height and density. Experimental work with captive birds is described and analyzed, and suggests that such precise habitat selection results from the behavioural integration of two orientation components. One is an innate tendency to build with up‐and‐down elements in the environment. The other tendency, acquired only after experience, is to build with those elements of the environment that have certain characteristics of height and density. The learning process involved in the acquisition of the latter tendency is thought to be reinforced by the rapid completion of a satisfactory stage.
QUANTITATIVE STUDY OF MIGRATION WITH 23‐CENTIMETRE RADAR*
Authors: Nisbet I. C. T.
Published: April 2008

A quantitative study was made of the displays of “angels” on the screen of a 23‐centimetre radar installation on Cape Cod, Massachusetts. The birds responsible for the displays were nocturnal migrants, mainly passerines.

Other things being equal, the density of angels decreased roughly exponentially with distance from the centre of the radar screen, being halved about every eight miles. The rate of decrease varied only slightly with total migration density, and could be used to estimate the total number of bird targets in the air.

Estimates obtained by this means were compared with estimates of migration density obtained from “moon‐watching” observations, which were reduced by a new method of calculation which incorporates radar measurements of the height of flight. Each angel was found to correspond to between two and twelve birds. After considering and rejecting other explanations, it is concluded that many birds migrate in groups at night. There is evidence that many species (including Parulidae, Turdidae and Emberizidae) migrate in small groups, rather than a few species in large groups. Groups of passerine night‐migrants are probably spread over a wide area, since it is rare to see two birds cross the moon together.

Once the average group‐size has been determined in this way, radar can be used to measure the density of migration over a large area. Estimates of low migration density have a standard error about 25%, but estimates of high migration density are less accurate, and very high migration densities cannot be measured at all, although they can be accurately identified as such.

The results in this paper cannot be applied directly to other radar stations, nor to other species of birds.
THE FOOD AND FEEDING HABITS OF TUFTED DUCK AYTHYA FULIGULA
Authors: Olney P. J. S.
Published: April 2008

The food and feeding habits of Tufted Duck Aythya fuligula are described, based on field observations and on the analyses of the stomach contents of 95 birds, all but one of them having fed inland; 57 were collected from a gravel pit near London, 28 from Northern Ireland and 9 from a number of English inland waters, in the shooting seasons 1959‐60 and 1960‐61.

The London birds in both seasons had fed primarily on molluscs, mainly Dreissena polymorpha. The Northern Ireland birds, where D. polymorpha does not occur, had a more variable diet, again mainly molluscs, but with some crustaceans, insects and plant seeds. The English birds had a similarly variable diet with the emphasis on crustaceans (Asellus spp.) and with some molluscs, insects and plant seeds. Brief information is given on the food of young birds.

It is suggested that the spread of D. polymorpha may be one of the factors explaining the recent spread of the Tufted Duck in certain areas. It appears that where one particular food such as D. polymorpha is not plentiful a more variable diet is taken, though molluscs always figure prominently. The type of food taken depends on the type of habitat used, the availability and size of the food items and on the methods of feeding.
OBSERVATIONS ON WINTERING BIRDS AND SPRING MIGRANTS IN TRIPOLITANIA
Authors: WatersR.A.M.C. W. E.
Published: April 2008

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

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

In Costa Rica, the Rufous‐tailed Jacamar inhabits both humid second‐growth and primary rain forest, from sea level up to about 3,000 feet. It subsists upon insects, including many large butterflies and dragonflies as well as numerous glittering beetles, all of which it catches on the wing.

The search for nest‐sites begins in the dry month of February; eggs are laid from late March until June; and the latest young fledge in July. Both sexes dig the nest burrow in a roadside bank, side of a gully, or the vertical wall of clay raised up by a great uprooted tree. At this time the male often feeds his mate. Burrows range from about 12 to 16 inches in length, are straight or curve more or less to the right, and dilate at the inner end to form a low, unlined nest chamber. The same burrow may be used in successive years.

About ten days elapse between the completion of a burrow and the start of laying. The pure white eggs are deposited at intervals of two or more days. In Costa Rica sets of two or three are laid, but farther north in Guatemala two sets of four were found.

The female incubates each night. The male replaces her before sunrise, and throughout the day they change places at intervals of 1 1/2 to 2 hours, sometimes more. The incubation period is 19–23 days.

The nestlings hatch with abundant, long, white down. They are prognathous and have well‐developed heel pads. They are very loquacious, calling from an early age and soon delivering beautiful, long trills much like those of the adults. Both parents bring them insects, one at a time; no other food was noticed. The male parent fed feathered nestlings about 2 1/2 times as often as the female. In 25 hours, two nestlings were fed at the average rate of 2·4 times each per hour, but there were great hourly fluctuations. Two young who remained in the nest unusually long finally left spontaneously, without parental urging. The nestling period varies from 20 to 26 days and is longest for late broods.

Jacamars wholly neglect the sanitation of their nests. They fail to give threat or distraction displays when a man or a small native mammal approaches their burrow.
THE FAIRY TERN GYGIS ALBA ON ASCENSION ISLAND
Authors: Dorward D. F.
Published: April 2008

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

The main types of habitat to be found in the Ibadan area are briefly described and their interrelationships considered. The relative degree of shade and cover afforded by each is discussed in relation to human influences.

The avifauna, comprising 266 species so far identified in the area, is classified as comprising forest, savanna, widespread and aquatic forms. The status and frequency of each species is indicated.

It is shown that the terrestrial element in the Ibadan avifauna is very evenly balanced between forest and savanna forms.

The ability of forest forms to emerge from the forest and occupy less shaded habitats is contrasted with the converse ability of savanna forms to enter forested habitats.

A number of species are separately noted in a supplement to Appendix 1 that show points of interest concerning their taxonomy, status or range.
BILL‐CLAPPERING DISPLAY IN THE COMMON HERON ARDEA CINEREA
Authors: Hudson M. J.
Published: April 2008

Bill‐clappering is shown to be a normal feature of the early phases of the breeding cycle in the Common Heron Ardea cinerea and the circumstances of its occurrence are described.

Possible origins of this behaviour and its probable function are suggested.

An attempt is made to show the development of Ciconiiform display from the integration of more simple patterns. The significance of bill‐clappering in the Common Heron appears to lie in the fact that it suggests an ancestral type of behaviour from which the complex display of the White Stork has evolved.
SEASONAL VARIATION IN THE FOOD OF THE PURPLE MARTIN PROGNE SUBIS IN KANSAS
Authors: Johnston Richard F.
Published: April 2008

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

During an 11‐month study of the Black‐headed Duck in eastern Argentina, observations were made on the marsh birds of Cape San Antonio, Province of Buenos Aires. These observations supplement the distributional and life history obtained by Gibson (1879–1920), Wetmore (1926) and others.

The deep, fresh‐water marshes characteristically are dominated by one of three plants: tules, cutgrass or cat‐tails. There were surprisingly few marshes with mixtures of these plants and few marshes which showed a gradual transition from marsh to uplands.

Marsh birds showed considerable adaptation in chronology of nesting and nest‐site selection for the seasonal water cycle of wet springs and dry periods in the late summer and fall. Some marsh birds were involved in nesting over a longer period than is usual in Northern Hemisphere marshes. As seems characteristic of all marsh birds, cover‐water edges were usual sites for nests. There were only a few species with restricted nest‐site selection, and competition between closely related species was noted only among the three species of coots.

A list of the marsh birds of the area is given, and comments are presented on the ecology and behaviour of selected species.
STUDIES OF THE DIEDERIK CUCKOO CHRYSOCOCCYX CAPRIUS IN THE TRANSVAAL
Authors: Reed R. A.
Published: April 2008

The migrant Diederik Cuckoo Chrysococcyx caprius was studied on a 72–acre area near the Klein Jukskei River near Johannesburg from 1955–1958. The birds first arrive in early October, after which the males take up territories and call continually until February; subsequent calls up to April are probably made by young birds.

Courtship displays, which involve courtship feeding, and egg‐laying follow the birds' arrival by about a month. The Red Bishop Euplectes orix was the species most commonly parasitized, with smaller equal numbers of Cape Sparrows Passer melanurus and Masked Weavers Ploceus velatus. The cuckoos' eggs differ according to the host species and in two cases hatched between ten and 14 days after laying. The chicks normally evict their hosts' offspring on the second or third day after hatching. The fledging period appears to be roughly 19–20 days, and there is a period of post‐fledging care lasting between 17 and 38 days, during which the chicks are fed different foods by different host species (grass seeds by bishops; insects of different sizes by weavers and sparrows).

The fact that the eggs and the calls of the chicks vary according to their host species suggest the existence of three separate host‐specific strains in this area. The incidence of brood parasitism in Red Bishops' nests varied from 7–50% and averaged 25%.
THE RECOGNITION AND TREATMENT OF VENOMOUS AND NON‐VENOMOUS INSECTS BY SMALL BEE‐EATERS
Authors: Fry C. H.
Published: April 2008

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

The pelagic distribution of the FulmarFulmarus glacialisoff eastern Canada has been used to test Fisher's (1952, 1966) hypothesis that Fulmar numbers are controlled by the availability of offal from the fishing industry. Fulmars are abundant on the fishing Banks off Newfoundland but not on those off Nova Scotia; by contrast, they are fairly common in the unfished waters south of Greenland. The Newfoundland and Greenland waters are colder than those off Nova Scotia, and it seems likely that temperature and other oceanographic factors, not fish offal, control Fulmar distribution in the western Atlantic. Since the ringing returns show that many of these Canadian birds are from British colonies, it is possible that fish offal may not be the key factor in the eastern Atlantic either.

Since there are no reliable quantitative data on the Fulmar's diet, it is difficult to suggest a specific alternative. However, the Fulmar is, over much of its range, a cold‐water species; it may eventually be possible to interpret Fulmar distribution in oceanographic terms, the key factor being its macroplanktonic food. However, the Fulmar population in the warmer waters of the eastern Atlantic remains an anomaly; it is not yet possible to explain the differences in ecology between the eastern and western Atlantic birds, either in oceanographic terms, or by the availability of fish offal.
A FIELD STUDY OF THE BEARDED BELLBIRD IN TRINIDAD
Authors: Snow Barbara K.
Published: April 2008

The Bearded Bellbird Procnias averano, a medium‐sized sexually dimorphic cotingid, was studied for three years in the Northern Range of Trinidad.

Its preferred habitat is primary forest at altitudes of 500–1,000 feet and with a rainfall near 100 inches. It is entirely frugivorous, taking mostly drupes. The seeds of the fruits eaten are regurgitated and nearly 2,000 were collected from below the male's calling perch and below nests. Most were from the families Lauraceae and Burseraceae, whose fruits have particularly nutritious pericarps.

Adult males own a calling territory from which they call throughout most of the day, and throughout the year except for the period of moult. In each territory there are special saplings where display and mating take place.

Only males call; the females are voiceless. The call is loud and far‐reaching. In Trinidad P. averano has only two calls, the Venezuelan birds have a third more musical call which appears to have been lost by the Trinidad bellbird during the past 60 years.

Both males and females visit the adult male in his calling territory. Here he performs a ritualized display to the visitor, which shows off his black and white plumage, the beard of wattles, and also a bare patch on the thigh. The visit of the female may culminate in mating. All aggressive behaviour observed was between males disputing over calling territories.

The female builds the nest, incubates, and rears the chick on her own. The very inconspicious nest is built of twigs that readily interlock. Nearly all the twigs are from two species of tree, and it is suggested that the specialized nest‐material may be essential, as the female bellbird builds only with the breast and feet. The clutch consists of a single egg. The incubation and fledging periods are both long, 23 and 33 days respectively. The female's visits to the chick are infrequent, brief, silent and inconspicuous. Many details of breeding behaviour indicate that the inconspicuousness of the nest is of paramount importance.

The nestling is fed on fruit which the female regurgitates. The main breeding season is from April to July with a minor one in October and November. It takes two and a half years for the male to attain fully adult plumage, and at least two years to achieve a completely adult call.

The relationship between type of nest, clutch‐size, feeding habits and sexual bonds in tropical forest birds is discussed. The bellbird is an extreme example of a species in which the need for a very inconspicuous nest and a diet of fruit have combined to promote polygamy, with the emancipation of the male from the nest, and to reduce clutch‐size to a minimum.

The bellbird's structural adaptations to its method of feeding in flight are discussed and a comparison is made with the birds of paradise. The male's adaptations for its primary function of self‐advertising are compared with the parallel adaptations evolved in the related Pipridae.
SEA‐BIRD BREEDING SEASONS ON CHRISTMAS ISLAND, PACIFIC OCEAN*
Authors: Schreiber Ralph W. , Ashmole N. Philip
Published: April 2008

Christmas Island, at 2° N, 157° W in the Central Pacific Ocean, supports 18 breeding species of sea‐birds. Data on the breeding seasons collected by the authors and other visitors to the island are analyzed in individual species accounts. Population estimates are given, the distribution of each species on the island is outlined, and for some species information on the sexual and moult cycles of marked individuals is presented. The Discussion concerns the ultimate and proximate factors controlling breeding seasons and the role of social factors in maintaining breeding synchrony in sea‐birds, the diversity of the breeding regimes exhibited on Christmas Island (summary and analysis in Fig. 2 and Table 5), and comparison of these regimes with those found in the birds of Ascension Island and the Galapagos Archipelago.
MOULT IN THE SHAG PHALACROCORAX ARISTOTELIS, AND THE ONTOGENY OF THE “STAFFELMAUSER”
Authors: Potts G. R.
Published: April 2008

There are three main types of plumage in the Shag, the juvenal which is brown, the post‐juvenal which is dark brown and the nuptial which is black‐green. The replacement of these plumages and the ontogeny of the Staffelmauser was studied in a sample of 566 Shags mainly from northeast England. The replacement of the juvenal primaries starts at the age of eight months with the loss of the innermost primary and continues outwards at a rate of about one primary per 17 days. Another cycle starts when the first reaches the 8th primary but both cycles soon pause for the winter. Successive cycles are established annually in August or September in this way, so that cycles which take longer than one year to complete result eventually in a Staffelmauser in which each feather is replaced once annually. Most individual Shags in a breeding population will retain feathers from two or three cycles, but a large sample of breeding adults of the same age will retain the feathers of four cycles.

The winter pause is considered an adaptation to the increased probability of adverse conditions at this time. The system described for the ontogeny of the Staffelmauser is applicable to those other sea‐birds which have been studied in detail, and is probably advantageous since it combines slow moult during the difficult early years with a highly efficient moult during the breeding years, especially where moult and breeding occur together.
HUNTING METHODS AND CHOICE OF PREY OF GYRFALCONS FALCO RUSTICOLUS AT MVTN IN NORTHEAST ICELAND
Authors: Bengtson Sven‐Axel
Published: April 2008

Gyrfalcons breeding near Myvatn in northeast Iceland were studied from 1960 until 1970. Hunting methods and successful attacks are described. The Gyrfalcon usually hunts low over the ground and tries to surprise and flush its victim and then stoop upon it. If this fails, it may pursue.

The choice of prey was studied by observations from mid‐May to September of Gyrfalcons carrying prey, and by examining food‐remains at eyries. Ducks and Ptarmigan comprised about 49% and 41 % respectively by number of individuals, and 62% and 35 % by estimated fresh weight. One pair utilised some 88 kg of food to raise foui young.

The proportion of Ptarmigan in the diet increased during the study, reflecting the increase of the Ptarmigan population and suggesting that Ptarmigan are the preferred prey since waterfowl were abundant all the time.
THE SOCIAL ORGANISATION OF BEE‐EATERS (MEROPIDAE) AND CO‐OPERATIVE BREEDING IN HOT‐CLIMATE BIRDS
Authors: Fry C. H.
Published: April 2008

In the colony‐nesting bee‐eater Merops bulocki of the northern savannas of Africa males preponderate in the proportion 1 ‐5 to 1 female, initial breeding occurs at varying ages, and adults of both sexes and all age classes, particularly one‐year‐old males, assist breeding pairs with nest excavation, incubation, and provisioning the pulli and fledglings. Up to three helpers can occur at one nest, and they may be siblings of a previous year's brood. Pair‐bonds are for life, and bonds formed between the breeding pair and their helpers may endure until next season. Some evidence suggests that other gregarious open‐country bee‐eater species are similar in these respects but that forest and solitary‐breeding savanna species have the sex ratio at parity and do not breed co‐operatively. Breeding dispersion of savanna species is related to specific size, the largest (which forage most widely) nesting in the densest aggregates.

Other instances of birds with comparable social organisations are briefly reviewed. The 80 species involved comprise broad systematic and ecological spectra and about 60 of them inhabit hot climates in America, Africa and Australia. It is suggested that co‐operative breeding provides a reserve of experienced individuals whose recruitment to breeding permits (1) fine control of stable populations in non‐seasonal habitats (tropical forest) within the capacity of the food resources; (2) crude adjustment of fluctuating populations in habitats with unpredictable rainfall (Australia), enabling them rapidly to recuperate from depression and to achieve the highest population level the improved food resources can sustain; and (3) regulation of populations in intermediate habitats (tropical savannas) by either means according to the dictates of immediate ecological circumstances.
MORPHOLOGY OF THE TONGUE APPARATUS OF C1R1DOPS ANNA (DREPANIDIDAE)
Authors: Bock Walter J.
Published: April 2008

Ciridops possesses a tubular tongue with a fringed tip and lateral sides. Closure of the tube is by overlap of the lateral fringes.

The tongue skeleton possesses an elongated basihyale, parallel paraglossalia with broad, rounded posterior processes and a slight concavity on the dorsolateral surface of the ceratobranchiale.

All the tongue muscles could be described, although some had been damaged. The M. hypoglossus anterior is absent. The M. ceratoglossus and the M. hypoglossus obliquus are large, the latter muscle inserts completely on the basihyale. A newly discovered muscle, the M. thyreohyoideus superior, is described.

The glottal muscles are described, and their actions in opening and closing the glottis are outlined.

Comparison of Ciridops (Drepanidinae) and Loxops (Psittirostrinae) suggests that the Drepanididae are monophyletic. The closest resemblance in morphology of the tongue apparatus is with the cardueline finches, not with the “coerebids”.
THE BREEDING OF URBAN WOODPIGEONS
Authors: Cramp Stanley
Published: April 2008

Egg‐laying in Woodpigeons in central London lasts from March until September in normal years, with peak production in April and May, contrasting markedly with some rural areas in England where few clutches are completed before May and the peak months are July and August. Both appear to be determined by food supplies; London birds feed mainly on bread, supplemented by vegetable foods, which is in ample supply. so that they require much less time for feeding than rural birds in winter and early spring. They are thus able to breed over the whole period for which they are apparently physiologically capable. Breeding success in central London is almost double that in Cambridgeshire and nearly 50% above that in other rural areas, due to markedly lower predation, especially at the egg stage. The factors governing the breeding seasons of different populations of Woodpigeons are discussed.
SUMMER DISTRIBUTION OF PELAGIC BIRDS OFF THE COAST OF ARGENTINA
Authors: Cooke Fred , Mills Eric L.
Published: April 2008

Eighteen species of sea–birds were observed from CSS ‘Hudson’ in the South Atlantic between the Rio de la Plata and Tierra del Fuego in late January and late February 1970. Major feeding areas were noted off Mar del Plata, the Valdes Peninsula and Tierra del Fuego, Argentina, the first two in rich modified or unmodified water of the subantarctic Falkland Current, associated with upwelling. The southernmost area had most birds, the northernmost fewest. A temperate–latitude assemblage including Yellow–nosed Albatross and Cory's Shearwater occurred off Mar del Plata in warmed water of subantarctic (Falkland Current) origin. South of 39°S these two species were replaced by Black–browed Albatross and Great Shearwater in cold offshore water of the Falkland Current. Off the Valdes Peninsula Black–browed Albatross, Great and Sooty Shearwaters, White–chinned Petrels and family groups of Magellanic Penguins occurred near the edge of highly–productive water of the Falkland Current. The largest feeding area, east of Tierra del Fuego, had Magellanic and Rockhopper Penguins, Great Shearwaters, King Cormorants, South American Terns and jaegers, but no oceanographic information is available. At 50°S prions and diving petrels appeared for the first time, marking a possible oceanographic discontinuity or proximity to colonies on the Falkland Islands. Several common species of the South Atlantic were not seen on the transect including Cape Pigeon, Southern Fulmar, Soft–plumaged Petrel, Schlegel's Petrel and Pediunker. Kelp Gull, South American Tern, Manx Shearwater and jaegers were rare or absent far from land. New southern limits for the western South Atlantic Ocean were established for Cory's and Manx Shearwaters, and the Great Shearwater was observed for the first time in Chilean waters.