Incubation Patch Research Articles

Testosterone-Induced Incubation Patches of Phalarope Birds

In order to determine the endocrine factors in the production of the incubation patch of phalarope birds (Steganopus tricolor and Lobipes lobatus), adults of both sexes have been maintained in captivity and injected with estradiol, testosterone, or prolactin, or with different combinations of these hormones. Only testosterone and prolactin in combination produced incubation patches in all birds, both male and female, in the two species.

Hormonal Control and Development of the Incubation Patch in Icterids, with Notes on Behavior of Cowbirds

Hormonal Control and Development of the Incubation Patch in Icterids, with Notes on Behavior of Cowbirds

TEMPERATURE REGULATION IN THE SOOTY TERN STERNA FUSCATA

SUMMARYTemperatures of eggs, young and adults of the Sooty Tern were measured under a variety of environmental conditions on Midway Island.The mean daytime body temperature of incubating adults (40·5° C.) was significantly higher than the mean (39·4° C.) for adults on nests at night.The mean incubation patch temperature (39·‐6° C.) was significantly higher than the means for incubated eggs without visible embryos (34·8° C), incubated pipped eggs (36·6° C), or brooded, newly‐hatched chicks (38·3° C).Severe heating by solar radiation is the principal environmental problem faced by nesting Sooty Terns. Shading by adults of eggs and young chicks prevents overheating; older chicks seek natural shade. When placed in the open sun, chicks of all ages can lose heat by vigorous panting. However, body temperature may rise almost to 45° C. and usually stabilizes in the lower range of prevailing black bulb temperatures.The relationship of physiological and behavioural mechanisms of thermoregulation to environmental conditions during the terns' nesting season on Midway Island is discussed.

Measurements of the testes and ovaries of birds, collected in Japan Alps range in summer

The measurements of the testes and ovaries of 21 species, 56 individuals of birds, collected in Japan Alps range during breeding season, are given.The incubation patch was present only in the females in Prunella rubida and P.collaris.

The Incubation Patch and Related Breeding Data of Crows

The Incubation Patch and Related Breeding Data of Crows

The Incubation Patch of Wild Geese: Its Recognition and Significance

A study of nine forms of wild geese in three arctic areas and in Illinois. Following an introduction on the use of own feathers for lining the nest, and earlier work on this behaviour, author deals with the occurrence and characteristics of the incubation patch in geese; and evidence of former incubation in wintering birds. The relation of the patch to egg laying and to hormonal factor as well as its value in age determination are discussed.

The Incubation Patch in Tinamous

The Incubation Patch in Tinamous

Variations in the Development of Broodiness in Fowl

The tendency of 14 Cochin Bantam hens to adopt chicks was tested by confining hens and chicks together in 50 by 50 by 150 cm. runways in a brooder house. The maternal behavior of the hens developed slowly and manifested itself in 4 definite stages, each stage separated by one or more days from those following it. These stages are: (1) brooding; (2) titbitting; (3) clucking; and (4) normal broody behavior. When stage 4 was reached, clucking continued for 10 days or more even if the chicks were removed. None of the hens ever developed an incubation patch nor adopted the broody posture to a normal extent. The socially dominant hens were slower to accept chicks than their less aggressive sisters. When the chicks were accepted, however, a remarkable uniformity existed in the time required for the non-laying hens to proceed from one stage to the next. Laying hens and immatures were prone to give incomplete responses. When 7 hens were tested simultaneously with the same group of chicks, 3 gave partial response ; the others none. Six hens tested with Mallard ducklings showed less inclination to peck at them and went from stage to stage much more rapidly than hens kept with chicks. One of these omitted stage i entirely.

A HISTORY OF THE FULMAR FULMARUS AND ITS POPULATION PROBLEMS.

Summary.The distribution of the Antarctic Fulmar F. glacialoides, the Pacific Fulmar F. glacialis rodgersii, and the Atlantic Fulmar F. g. glacialis is described. In the region Iceland‐Faeroes‐Britain (and Norway) the breeding distribution of the Fulmar has undergone a revolutionary change.In Iceland the Fulmar nested in the seventeenth century perhaps only on Kolbeinsey and Grimsey in the north. In the middle of the eighteenth century a spread and increase started; by 1949 there were at least 155 colonies, many large. The Fulmar spread to the Faeroes in the early nineteenth century and now breeds in great numbers on every island. In 1878 the Fulmar spread from the Faeroes to Shetland; until then its only British station was the very large colony on St. Kilda, known since 1697 and large then. It has now spread round nearly all Scotland, Ireland, England and Wales, and is prospecting south and south‐east England. In 1949 there were at least 365 breeding colonies in Britain, and 212 further stations at which Fulmars were prospecting or occupying nest‐sites but had not been proved to breed. About thirty new stations are now being prospected yearly in Britain. At present over a hundred thousand nest‐sites are occupied at British breeding stations, of which about a third are on the one traditional station of St. Kilda, where regular harvesting ceased by 1921.The world population of the Atlantic Fulmar occupies over a million nest‐sites yearly, but probably not many millions.There is no evidence that the Fulmar's numbers are controlled by either parasites or predators, except sometimes by Man. Its food is described; it eats all manner of plankton and offal and any fatty food avidly.It is suggested that the increase in the Fulmar population was made possible when man produced new and regular supplies of fatty offal, at first by the ship's‐side flensing of whales and, when the supply of whales became exhausted, by the discarding of trawler waste and fish‐guts, and that this increase was, and is, dependent on this food rather than climate, nest‐site supply or predation. In a direct sense the Fulmar appears to be now partly a dependant of Man.The Fulmar's breeding season is strikingly constant over its full breeding range. But there is a marked difference between small and large colonies in breeding success, and a certain difference in season. It is likely that the new colonies in Britain are being prospected and established by young birds, and that their reproductive inefficiency is due to the youth of their inhabitants, not to the “ Fraser Darling Effect”.The suggestion that adult Fulmars breed not every year, but periodically, is rejected. On the contrary, it appears that the Fulmar spends the first years of its life at sea. The length of this period is unknown. In the next period of a Fulmar's life it develops an incubation patch and a drive to sit on a nest‐site, but cannot lay or fertilize an egg. This period may last for four or five years, and one marked Fulmar has been taken at a cliff (and therefore in this period of its life) in the fourth season after that in which it was hatched. When it is perhaps 8 or 9 years old, possibly 7, the Fulmar breeds, and probably continues as a rule to do so annually for the rest of its long life if it is healthy and can find a mate.