Notes on the biology of the Mauritius Black Bulbul Hypsipetes olivaceus

The Mauritius Black Bulbul Hypsipetes olivaceus is a threatened passerine endemic to Mauritius. Direct observations of food items indicate that it is an arboreal omnivore. Animal prey consists mostly of insects and native day-geckoes (Phelsuma spp.). A wide variety of native and exotic fruits is also taken. The species is apparently monogamous, With an egg-laying season extending from at least November to February, usual clutch and brood sizes of two to three, ability rapidly to lay repeat clutches in a new nest, and post-breeding complete moult. In these respects, its annual cycle resembles that of the other native Mauritian passerines. It occurs at very low population density compared to its Indian Ocean congeners; possible reasons for this are given.