Breeding biology and nidology of Oriental skylark (Alauda gulgula) in district Bajaur, Khyber Pakhtunkhwa, Pakistan

Abstract

A general field survey about Oriental skylark (Alauda gulgula) breeding biology and nest structure (nidology) was carried out during (April, May, June, and July) 2018 and 2019, in district Bajaur. This study was conducted in order to record all the ecological factors that hurdle for the successful breeding of skylark in the study area. For this purpose, we studied 33 nests from egg laying up to the fledging stage. As a result, morphometric measurements of 112 eggs were recorded. Overall eggs were oval dusty white or grey white with black spots and mostly smooth or of somewhat rough texture. Average egg weight 3.0 g, length 2.2 cm, width 3.27 cm 2 and volume 3.65 cm 3. Likewise explored average clutch size 3.39, incubation period 12.07 days, the number of eggs hatched 3.30 (95.19%), fledged 3.18 (97.34%), and breeding success (89.20%). After normal fledging, the floor of nests was recorded. The shape of nests was entirely round to preferential round; the average nest diameter 9.48±0.8 cm, cup diameter 7.86±0.6 cm, cup depth 6.21±0.5 cm, and nest weight 17.61±0.9 g. The main cause of breeding failure and nest loss was brutal nests and egg destruction by locals and a high rate of land as well avian predators.