Egg characteristics and clutch size in an endemic avian species, the Brown Rock Chat, in Haridwar, India. - V.K. Sethi, A. Kumar, D. Bhatt. - Berkut. 19 (1-2). 2010. - P. 147-152.
Out of nine species of genus Cercomela distributed primarily across the African continent (Muscicapidae), only one species, i.e. C. fusca, occurs in India. It is endemic to the Indian subcontinent and hence deserves importance from conservation point of view. Data have been gathered on egg characteristics and clutch size of the Brown Rock Chat during 2004 to 2006 in the urban and suburban areas of district Haridwar (29º N; Himalayan foothills of Uttarakhand state), India. Brown Rock Chat laid one egg per day. Weight of freshly laid eggs ranged from 2.42 to 2.57 g and averaged 2.49 ± 0.02 g (± SD). The length, breadth and volume of 100 eggs averaged 20.67 ± 0.25 mm, 15.84 ± 0.36 mm and 2.65 ± 0.14 cm3 respectively. No significant variation occurred in average weight of successive eggs; however, average egg weight in individual clutches differed significantly among different females. Egg and clutch sizes did not differ among broods and breeding months. Three- and four-egg clutches were the only clutch sizes recorded during the present study. Clutch size averaged 3.4 ± 0.5 (± SD), more nests (60.3%) had three-egg clutches than four-eggs (39.7%). [English].
Key words: Brown Rock Chat, Cercomela fusca, egg weight, egg size, clutch, brood.
Address: D. Bhatt, Avian Diversity and Bioacoustics Lab., Department of Zoology and Environmental Science, Gurukula Kangri University, Haridwar 249 404, Uttarakhand, India; dineshharidwar@gmail.com.