Although the family Vangidae provides one of the most striking examples of adaptive radiation in the avifauna of Madagascar, basic information on the breeding biology of each species is lacking. To examine the breeding system of the White-headed Vanga Leptopterus viridis, a species endemic to Madagascar, we studied the contributions made by males and females of nine pairs (involving nine banded individuals) to nest building, incubating, brooding, and feeding the young. The study was conducted from November to December in 1999 and 2000 at the Strict Nature Reserve of Ankarafantsika (Ampijoroa). Males defended dispersed territories, individual males paired with single females, and all observed copulations took place between females and males on whose territories they nested. During the nest-building stage, males and females provided material in equal proportion. Both sexes participated in incubating and brooding. During the nestling period, both sexes delivered food (mainly spiders and caterpillars) to the nestlings. In two of nine pairs, pairs and extra birds whose greater coverts were molting shared the territory and extra birds allopreened with pairs. Using the CHD gene sexing method, we determined that two of these extra birds were males. These extra males did not help feed young, but they mobbed animals that approached the nest. These results suggest that White-headed Vangas are cooperative breeders (of the singular-breeding type), where immature males assist in mobbing.
The family Vangidae is monophyly group of species which underwent extensive in situ radiation within Madagascar. Although the foraging ecology and the phylogeny of this family have been studied, basic information on the breeding biology of each species is poorly known. We described the breeding ecology of Van Dam's Vanga Xenopirostris damii, which is endemic to Madagascar, and considered the mating system of this species. The research was conducted at Ampijoroa Forest Station in the Ankarafantsika Strict Nature Reserve during October to November in 2000. Six pairs were observed in the study area. Each pair had home range which did not overlapped with each other. No interaction was observed among pairs. Parental activities in nest building, incubation and nestling stages were observed at three nests. Both sexes participated in these activities, and no helpers were observed. The non-overlapping home ranges and biparental care suggest that the mating system of Van Dam's Vanga is socially monogamy.
The breeding ecology of the Hook-billed Vanga Vanga curvirostris, which is endemic to Madagascar, was studied on the Masoala Peninsula, northeast Madagascar in October 1999, and in the Ankarafantsika Strict Nature Reserve from October 2000 to January 2001. Five nests discovered during our study were all located 3-10m above the ground in the forks of trees ranging from 390-1260mm in diameter at breast height. Two adults (perhaps a heterosexual pair) participated equally in nest construction, incubation, and care of the young at each nest, and no helpers were observed. Incubation lasted between 22 and 24 days. The nestling period was 20 to 22 days, and the parents delivered invertebrates and small vertebrates, including mainly geckos and chameleons, to nestlings. External morphometric measurements of specimens suggest that the Hook-billed Vanga lacks sexual dimorphism in body size. Less-marked sexual dimorphism, biparental care, and similar sex roles show the Hook-billed Vanga to have a monogamous mating system.
Nestling diet of Japanese Wagtails (Motacilla grandis) was investigated by the neck ligature method and compared with the food availability in their feeding habitat during the breeding season of 1999 in Higashi Hiroshima, western Japan. Nestling diet comprised of 85.5% insects, 14.2% arachnids and 0.3% chilopods in individual number basis. Odonata order comprised nearly one-fourth of the diet in dry weight basis. Diptera, Lepidoptera, Coleoptera, Orthoptera and Arachnida were also important contributors to the total prey weight. Chironomidae and Ephemeroptera families were the most numerous prey items but their contribution to the total prey weight was small. Electivity indices indicated that the Japanese Wagtail prefer certain prey items (Libellulidae, Tipulidae, Dytiscidae) when collecting prey for the nestlings.
I studied the risk-taking behaviour of three species of corvid scavenger at carcasses during a severe winter. The dominance hierarchy was clear-cut, with ravens Corvus corax being most dominant, hooded crows Corvus corone intermediate, and magpies Pica pica least dominant. Dominant species generally excluded subordinates from access to the carcass. As predicted, the most subordinate species present was almost always the first to move to the carcass when it was unoccupied, either after first light or after a "panic" in the feeding flock caused by the real or apprehended presence of a predator in the vicinity. When relative abundance of each species was taken into account, this result was very highly significant both when magpies were the least dominant species present and when hooded crows were the least dominant species. This was despite apparent vulnerability to predation being highest in magpies and lowest in ravens. Alternative hypotheses to explain the data are considered. The evidence suggests that the least dominant (and so hungriest) species were willing to accept the cost (higher predation risk) involved in being the first individual to move to the carcass, in order to obtain the benefit of food from which they were normally excluded.
We ringed a female House Sparrow (Passer domesticus) at the Teuri Island, off Haboro, northern Hokkaido on 3 May 1998. Although there are several observation records of the species in northeastern Japan (Hokkaido, Akita and the satellite islands in the Japan Sea), this was the first House Sparrow ringed in Japan.