Mortality and survival of eggs and chicks of Western Reef Heron Egretta gularis on Nakhilo Island, Persian Gulf, 2008

Abstract

In a study on breeding processes of Western Reef Heron Egretta gularis carried out from March to September 2008 on Nakhiloo Island, we estimated the breeding population, mortality, natality and the breeding success of this species. The breeding success during the incubation, nestling, post-nestling and overall stages were 62.1, 46.4, 39.2 and 49.2%, respectively. Eating of the eggs by Black Rat Rattus rattus, high temperature and leaving of nests without cause were more important reasons of their mortality. The average weight of pulli at birth was 22.2±0.61 and at the flying stage was 590±10 g. Key words: Breeding, Egretta gularis, mortality, survival, Nakhiloo Island, Persian Gulf, Iran.