SHIGESADA Nanako Ass. Dept. Biophysics, Faculty of Sci., 理学部, 助手 (70025443)
MURAKAMI Okimasa Ass. Dept. Zool., Faculty of Sci., 理学部, 助手 (30025415)
TAKI Akio Ass. Dept. Zool., Faculty of Sci., 理学部, 助手 (30025340)
ABE Takuya Assoc. Prof. Dept. Zool., Faculty of Sci., 理学部, 助教授 (00045030)
|Budget Amount *help
¥5,000,000 (Direct Cost: ¥5,000,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1987: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1986: ¥2,500,000 (Direct Cost: ¥2,500,000)
Some sympatric animal species overlap their resources such as food, nesting site, etc. In such cases, different specis often show social relationsips analogous to the intraspecific ones; territoriality, flocking or schooling, dominance order etc. The project focused on the interspecific social relationships of some species group, and to what extent are the concepts on intraspecific social relationships applicable to the interspecific ones were examined.
In mixed-species winter flocks of passarine birds, Aegithalos caudatus leads the flock, and other passarine, Parus major etc, join to and leave from them everyday. But in some cases, a pair or two of Aegithalos leave the flock and join to the other mixed-species flock, moving as floolwers.
In mixed-species schools consisting 5 spp. of shrimp eating cichlid fish, 2 species consisted "core school" and the other 3 spp. joined to them during the school passed through their own home range. Their feeding frequencies were higher than those when they were alone: interspecific social facilitation was recognized.
Among forest-floor inhabiting 7 ant species, hierarchical stratification among the same life type derived from the complex of body size difference, home range size, antagonistic behaviour and admittive one was recorded.
Two species of algal feeding limpets, which are competitive being young shells of both species settle on Ralfsia zone, but Siphonaria adults feed exclusively on Enteromorpha and allow the growth of Ralfsia. Moreover, migratory type of Siphonaria, which are socially inferior to the residential type, Expanded the enteromorpha-free area allowing more space for the growth of algae, thence more space for the settlement of both species.