Life history of the Brown-eared Bulbul

Abstract

1. Two-season observations (1965, '66) on the breeding biology of Hypsipetes amaurotis in Samizu Village, Nagano Prefecture, are reported.2. Most of the nests were found in a somewhat isolated tree 4-5m high and were placed at average 2.8m from the ground below the dense canopy mixed with tendrils (thus protected from bird predators) and at about 1m above the low bushes (thus hard to reach for ground predators).3. Eggs of a clutch were laid daily in the early mornings, and the clutch-size was 4 in 8 nests and 3 in one.4. Female only incubated and her true incubation started from the night when the third egg of the clutch of four had been laid. Incubation period was 13-14 days and on and off sessions were average 29.9min and 12.81min. respectively. Feeding of female by the male was not observed either on or near the nest, although the latter type might exist.5. Hatching of a clutch required about 12 hours, but in one exception 24 hours.6. Female fed the chicks 60% of the total feedings. Chick foods were mainly insects mixed with some fruits of trees. 96.8% of the faeces of chicks were swallowed by the parents at the nest.7. Female only brooded, and under low temperatures it was continued even until the night before the chicks left the nest. The nestling period was only 10-11 days, and the family group remained about two months in the territory.8. Territories were average 1, 400m2 and were A-type of Mayr's classification. The male's, 'calling patrol' over the territory, characteristic in this species, was observed in the early morning through the nesting to the fledging periods.9. Most territorial fightings were intraspecific, but were also directed to shrike, blue magpie, jay or carrion crow. 80% of the territorial defense were made by the male, and the intensity increased markedly toward the fledging period of the chicks.