Some breeding and ecological aspects of heronry birds at Soor Sarovar Bird Sanctuary Agra, Northern India

Multi-species heronry at Soor Sarovar Bird Sanctuary, Agra was studied for some breeding and ecological aspects. This is an established heronry in semi-arid region with less than 600 mm rainfall and temperature range of 2oC to 48oC. Two near threatened (Black-headed Ibis and Darter) and twelve least concerned species nested in colony during late summer and rainy season. They were categorized as the early arrivers (Black-crowned Night Heron, Little Egret, Cattle Egret, Darter and Grey Heron), late arrivers (Intermediate Egret, Indian Pond Heron, Great Egret, Black-headed Ibis, Purple Heron and Asian Openbill) and very late arrivers (Eurasian Spoonbill, Little Cormorant and Indian Cormorant). Total Nest occupancy at a time followed the rainfall pattern of the locality. Nest occupancy calendar was recorded in the form of pre-egg laying, egg laying and chick rearing dates for all the species. Nesting height-bird size hypothesis was checked as mixed results as the stratum specific birds proved the hypothesis right, while stratum interface birds suggested relook of the hypothesis. Heronry threat, disturbance behavior of the birds and disturbance distance were recorded. Buffer establishment and heronry protection measures are recommended for conservation of the source population. The breeding phenology data could be used as baseline as indicator tool for climate change impact.