Nagata, H. 2001. The growth bars on tail feathers in the male Styan's Grasshopper Warbler may indicate quality. -J. Avian Biol. 32: 319-325.We propose that growth bar size may indicate the quality of individuals in Styan's Grasshopper Warblers Locustella pleskei. Positive correlations of an individual's standardized growth bar width between years showed that some individuals of both sexes were usually in better condition than others. The survival rate of males with wider growth bars was higher than that of other males. These survivors might have survived better because of a better body condition. We also examined the relationships between growth bar width and reproductive parameters (arrival date, pairing date and reproductive success). Males with wider growth bars arrived earlier, acquired a mate earlier and achieved higher total reproductive success by breeding twice. In females, growth bar width was correlated with reproductive parameters (arrival date, pairing date and total reproductive success), but not with survival. These results suggest that males with wider growth bars were of higher quality than those with narrower bars. The contrasting results for the two sexes may be explained by differences in their breeding tactics.

Japanese goshawk was classified as a vulnerable species in the Red Data Book. There have been possibilities of a decrease of genetic diversity accompanied by habitat loss and genetic pollution due to hybridization with escaping imported goshawks. In this paper, genetic diversity, gene flow and conservation of Northern Goshawk (Accipiter gentilis) in Japan are discussed and compared with that in Central Asia. We used 11 newly developed microsatellite markers and also adopted six previously published markers. Genetic diversity was shown to be maintained with 0.58 as mean heterozygosity and 3.95 as mean allelic richness. The degree of genetic differentiation across all populations was low (Nei's genetic differentiation index = 0.036, Wright's genetic differentiation index = 0.039), possibly due to gene flow via adjacent regions (average number of migrants = 4.26; 0.68-20.30). However, it is possible that slight differentiation resulted from the short divergence time and/or inflow of escaping imported individuals. We recommend that goshawks in eastern Japan should be managed as a single unit. They do not appear to be under threat genetically at present, but there is the potential for rapid loss of genetic diversity. For future conservation, investigations of dispersal routes and actual conditions of gene flow are also recommended. To prevent further inflow of escaping goshawks into natural populations, it is desirable to reduce importation of goshawks and to enact a regulation obliging purchasers to register imported goshawks.

Abstract. We conducted a study to clarify the impact of bush fires on the structure of non-breeding flocks of the Red-backed Fairy-wren Malurus melanocephalus cruentatus in the Australian monsoon tropics. Overall, the mean group size was large in the mid dry season, becoming smaller with the progress of season. Large groups occurred at burnt sites, while at unburnt sites group size was smaller owing to a higher proportion of pair-sized groups. Bush fire destroyed habitat and forced resident birds to emigrate. Conversely, unburnt sites were used as a refuge during fires. However, in the non-breeding season, such stable habitats were occupied by stable and small-sized groups and were already saturated. Therefore, individuals that immigrated into these habitats during fires were forced to emigrate again. After a fire, many birds invaded burnt sites from the surrounding area and aggregated in large but unstable flocks that consequently diminished due to the individual separation of young males just before the breeding season. Bush fires resulted in the reorganisation of groups and re-establishment of territory.

No abstract