Nehafta Bibi, Faiq Jan, Munawar Saleem Ahmad and Haitao Wang, 2021. Effect of Luminance on Visual Performance by Secondary Cavity and Non-Cavity Nesting Passerines. Pakistan J. Zool., 53:  1973-1976. DOI: https://dx.doi.org/10.17582/journal.pjz/20200802060800