Global Ecology and Conservation (Oct 2021)
Of irrigation canals and multifunctional agroforestry: Traditional agriculture facilitates Woolly-necked Stork breeding in a north Indian agricultural landscape
Abstract
Conservation of biodiversity alongside agriculture is now a global priority. Tree-nesting waterbirds have a tenuous relationship with farmlands because their survival requires farmers to retain trees and wetlands amid croplands. Research on such birds is rare on tropical and sub-tropical agricultural landscapes where high human densities and intensive farming ostensibly deteriorate breeding conditions. We explored breeding ecology and nest site selection by the single-nesting Woolly-necked Stork (Ciconia episcopus) in Haryana, north India using 298 nests from 166 locations discovered between 2016 and 2020. We determined the relative strengths of association of nest locations with natural features (trees, wetlands), human presence (habitation) and artificial water sources (irrigation canals) to understand cues used by breeding storks to situate nests. Woolly-necked Stork brood size from 42 successful nests was relatively high (3.1 ± 0.9 SD), with nests close to human habitation and wetlands having smaller broods. Storks showed high nest site fidelity (44.5% of sites used > 1 year), rarely nested on man-made structures (electricity pylons; 8.4%), and distributed nests in a clumped pattern. Woolly-necked Storks situated nests ambivalent to natural features but associated strongly with man-made features (positively with irrigation canals; negatively with human habitation). Contrary to expectations, most nests were not on the tallest trees but on the medium sized, native Dalbergia sissoo though storks situated nests on two tall trees (native Ficus religiosa and exotic Eucalyptus sp.) far more than the trees’ availability. All three tree species were favoured either for traditional agroforestry or local religious beliefs. Traditional agriculture in Haryana supported a substantial breeding population of Woolly-necked Storks facilitated by agriculture-related components rather than existing natural features. This novel scenario contradicts conventional narratives that suggest multi-season small holder tropical and sub-tropical agriculture degrades breeding conditions for waterbirds. Our findings in Haryana reiterate the need to assemble a diverse conservation toolkit of different locally relevant mechanisms supporting biodiversity amid cultivation.
