Drivers of biodiversity at macroscales have long been of interest in ecology, and climate and topography are now considered to be major drivers. Because humans have transformed most of the Earth's land surface, land use may play a significant role as a driver of biodiversity at a macroscale. Here we disentangle the relationships among climate, topography, land use, available energy (measured by the normalized difference vegetation index [NDVI]), and species richness of Japanese forest birds. Species richness was better explained at 40‐ and 80‐km resolutions than at 5‐, 10‐ and 20‐km resolutions; it was explained by climate, topography, and land use, and the effects of land use were fully incorporated into those of climate and topography. As temperature increased and elevation decreased, natural forest area decreased, and this decrease intensified in warm lowland areas. With the loss of natural forest, species richness decreased below a certain threshold. As temperature increased and elevation decreased, species richness and NDVI increased slightly or were unchanged in cool highland areas and decreased in warm lowland areas. Species richness increased linearly with the increase in NDVI. Most effects of climate/topography on species richness in warm lowland areas were shared by those of land use, suggesting that the decrease in species richness in warm lowland areas has been caused by loss of natural forest. Therefore, it is suggested that climate and topography determined land use intensity, which in turn, drove species richness through the depletion of available energy. Increasing temperature and decreasing elevation leads to both benefits (increase in potential available energy) and costs (depletion of energy by human land‐use change) for forest birds. These costs seem to override benefits in warm lowland areas.

Summary1. In many studies on cooperative breeding, helping by auxiliary individuals is considered to enhance the reproductive success of breeders. However, confounding factors other than helping could cause the differences. 2. The endemic Madagascan rufous vanga Schetba rufa (Vangidae) is known as a cooperatively breeding species. In order to evaluate the effect of helping in this species, we compared the reproductive success of breeding pairs helped by auxiliary birds, and pairs breeding alone, based on a 6-year study of an individually colour-banded population in the Ampijoroa Forest Station, western Madagascar. 3. This species is single-brooded. Brood reduction was rare and most cases of nesting failure were due to total loss of clutches and broods, probably as a result of predation. 4. Monogamous pairs with one to four auxiliary birds comprised 24 -43% of all breeding groups. Most auxiliary birds were male offspring remaining in their natal territory. Auxiliary males provided a considerable contribution towards antipredator defence, territory defence and to the provisioning of nestlings. In about one-third of the groups, however, the auxiliary males did not help at all. Male offspring may remain in their natal territory in order to avoid harassment by other territorial individuals, and to increase the probability of territory acquisition and of copulation with unrelated breeding females. 5. The probability of breeding successfully was higher, and the number of fledglings produced was larger among pairs with auxiliary birds than among those breeding alone. However, provisioning by auxiliaries neither enhanced the growth rate of nestlings, nor reduced the number of days they required to fledge. 6. A pair-match comparison of the same pairs between years with and without auxiliaries showed no effect of group size on their reproductive success. Even provisioning by auxiliaries did not affect the reproductive success. 7. Pairs accompanied by auxiliary birds for more than 1 year enjoyed higher reproductive success even in those years when they were without auxiliaries than did pairs always breeding alone. 8. Neither the simple presence of auxiliaries nor their helping behaviour enhanced the reproductive success of breeding pairs. The quality of the breeding pair and /or their territory may have affected their reproductive success and, as a result, increased the number of auxiliaries.

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.

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