Vinaya Kumar Sethi

Nesting success of the oriental magpie robin Copsychus saularis in nest boxes and tree cavities

Information on the nesting success of birds in the Indian subcontinent is almost negligible. In the present study factors affecting nesting success were studied over four years (i.e. 2011–2014) in a color ringed population of the oriental magpie robin (OMR) in an urban habitat of Haridwar district (29°55′N, 78°08′E), Uttarakhand, India. Objectives of our study were 1) to assess whether nest box affects nesting success in the OMR or not 2) to compare breeding data obtained from nest boxes with tree cavities. Out of total 114 nests built in both nest boxes and tree cavities, 80 nests were successful in producing at least one fledgling resulting 69.25% nesting success. Nesting success did not differ significantly between nest boxes and tree cavities or during different years. No correlation was found between territory size and nesting success (correlation coefficient = 0.41). Observations indicated that predation accounted for the maximum egg loss and nestling mortality. Predation rate was higher in tree cavities but did not differ significantly during different years and between nest boxes and tree cavities. In all years but 2011 clutch size was significantly higher in nest boxes than in tree cavities. However, incubation period, provisioning period, number of eggs hatched and number of young fledged did not differ significantly between nest boxes and tree cavities. When provided, nest boxes were occupied more frequently at all study sites indicating that nest box may act as an alternative nesting site for the OMR and perhaps for other secondary cavity nesters facing scarcity of nesting sites due to rapid urbanization.

PROVISIONING OF YOUNG BY THE ORIENTAL MAGPIE-ROBIN (COPSYCHUS SAULARIS)

Abstract Information on provisioning behavior of birds in the Indian subcontinent is almost negligible. We studied provisioning of nestlings of the Oriental Magpie-robin (Copsychus saularis) in 11 nests in relation to brood size, nestling age, and time of day during March–July 2006. Both parents fed the nestlings. However, the rate of provisioning trips by females was higher (t = 9.51, df = 10, P < 0.01) than for males. Brood size and time of day did not affect the provisioning rate. Age of nestlings was an important factor affecting rate of parental provisioning. Nestlings were fed more as they became older and there was correlation (Spearmans rho = 1) between parental provisioning trips and nestling age.