Population estimation and breeding biology of the House Crow Corvus splendens on Kharg Island, Persian Gulf

This study was conducted at five sites on Kharg Island in the Persian Gulf:Ershad Guest House, Falat-e Ghare, Melli Bank, Sadaf cinema and the petrochemical site.Estimates of the population size of the House Crow Corvus splendens were made on 10September 2009, 20 December 2009 and 10 January 2010. The breeding population wasestimated on 22 July 2010. The population of House Crows was 5,212 individuals on 10September, 4,950 individuals on 20 December and 5,500 individuals on 10 January(average 5,220 individuals). The breeding population was estimated as 1,451 pairs based on the number of active nests, and a total of 1,871 old nests were also located. During the summer, autumn and winter seasons, the non-breeding House Crows roosted on 32 trees of Ficus bengalensis, 62 Eucalyptus, and one Ziziphus aucheri. The non-breeding population was more than the breeding population (5,220 non-breeding individuals, and 1,451 breeding pairs). Nests of the House Crow were composed mainly of two types of material, wood and pieces of discarded wire. The clutch size was 3–5, but most of the nests had 4 eggs. The population of this species on Kharg Island increased from about 40 individuals in the early 1970s to 5,500 in 2010.