With primary attention to feral species, some important, recent trends in avian physiology have been selected and briefly described. Included are investigations of the exchanges of gases between embryo and external environment during incubation; structure and function of the lung-airsac system; avian energetics; control and energetic cost of molt; osmoregulation, ionoregulation and nitrogen excretion, including roles of kidney, lower gut, salt glands, and renin-angiotensin system; endocrinology; and orientation and navigation. Among these trends there has been an increase in the spectrum of species investigated, greater effort to make measurements under natural conditions and successes with experiments on feral species in the field. Physiological investigations have been facilitated by the great fund of information on the natural history and zoogeography of birds.
The migratory activities or Zugunruhe in caged Emberiza rustica have been studied. The experiment was conducted by exposing the above species to different artificial temperatures in three chambers which were maintained at 22°C, 15°C and 8°C, respectively. The photoperiod was increased from 9 to 15 hours and then decreased from 15 to 9 hours during the period from March to December, 1978. The activities in the darkness, Zugunruhe of the bird group exposed to 22°C increased in July and August and terminated in September; and in the 15°C group, moderate Zugunruhe appeared only in July. In the 8°C group, however, slight Zugunruhe appeared only in July and then increased Zugunruhe appeared in September. Thus, all three different temperatures induced the onset of Zugunruhe in spring, however, it was at a low temperature such as 8°C that Zugunurhe was induced both in spring and in autumn.
The objective of this brief review is to present the current status of our knowledge regarding the endocrine and behavioral responses to crowding stress in avian species. The main resultant of this social stress is reflected in partial reproductive failure and other physiological disorders. Epinephrine is possibly one of the principal hormones which play a substantial role in counteracting the stress situation. The present work also reports on several environmental factors which triggero the situation of social stress Finally the possible mode of action of stress response has also been discussed.
The predatory and anti-predatory systems in the Black-tailed Gull (Larus crassirostris), Slaty-backed Gull (L. schistisagus), Rhinoceros Auklet (Cerorhinca monocerata) and Jungle Crow (Corvus macrorhynchos) were studied during three breeding seasons from 1979 to 1981 on Teuri Island, Haboro, Hokkaido. The Jungle Crow was the main egg predator in late April and May and killed auklet chicks in late June. Slaty-backed Gulls killed auklet chicks in middle June, and then changed their prey to Black-tailed Gull chicks in late June and July as gull chicks became available. Adult Black-tailed Gulls mobbed and swooped at Slaty-backed Gulls attacking chicks but these direct anti-predatory behaviours did not decrease the predation success significantly. Slaty-backed Gulls and Jungle Crows usually killed auklet chicks in the early morning when they came to the burrow entrance. Burrow nesting and nocturnal activity of auklets were regarded as indirect anti-predatory systems.
Nine species of stragglers and rare birds were recorded from Taik, southern Tokachi district, Hokkaido, from September 1970 to May 1981. A single bird of Accipiter gentilis albidus was observed on February 10, 1981 at Hikata. A single bird of Falco rusticolus was seen from January 11 to February 20, 1980: January 11 at Kosei, January 20 at Shimo-taiki, February 1 at Memu and February 20 at Furubetsu. A single bird of Falco columbarius was observed on March 10, 1979 at Toyosato. A single bird of Grus grus was observed in September, 1970 at Bisei and November, 1971 at Seika. Two birds of Grus monacha was seen in late October at Nakajima, from 1972 to 1974, and a single bird of G. monacha was seen at Nakajima from April 29 to May 6, 1981. A single bird of Grus canadensis was seen from December 5 to 23, 1979 at Seika. Two species of Grus were seen in company with Grus japonensis. A single bird of Tringa guttifer was seen from September 21 to 23, 1980 at Kosei. A single bird of Emberiza pusilla was seen among a flock of Acanthis flammea from January 25 to 28, 1978 at Kaishin. A single bird of Corvus monedula dauuricus was seen from April 3 to 8, 1978: April 3 at Taiko and April 3 at the town of Taiki, and on March 13, 1980 at Takuhoku. These records are the first ones from Tokachi District.