Nesting habitat preference and breeding of Asian Woollyneck (Ciconia
episcopus) in Nepal
Abstract
Background: Asian Woollyneck Ciconia episcopus is large wading bird
whose conservation status has been recently down-listed, despite a lack
of general knowledge on its nesting ecology and breeding success. Thus,
in this study we conducted the most comprehensive survey on the nesting
ecology of this species to date. Methods: We located 39 nesting sites
across 18 districts of Nepal and recorded nest tree characteristics for
the nine tree species they nested in. We also used Maxent modelling to
further understand factors important for nesting habitat suitability and
to identify new areas for future surveys. Results: They most commonly
nested in Simal Bombax ceiba (n =21), followed by Sal Shorea robusta
(n=6) and Salla Pinus roxburghii (n=4). The mean height of the nesting
tree, nest height and tree diameter were 29.8 ± 5.8m (±SD), 1.03 ± 0.35m
& 25.3 ± 5.8 m respectively. Nesting and fledging success were
additionally recorded from 31 nesting attempts at 19 of these nesting
sites between 2016 and 2020. Woollyneck had an estimated nesting success
probability of 0.81 ± 0.07 and a mean fledging success of 1.94 ± 0.25
(±SE) chicks per nest. MaxEnt modelling identified a total potential
suitable nesting habitat area of 9.64 % (14228km2) of total area in
Nepal, with this located within 72 districts (out of 77), mostly in the
western part of Nepal. The modelling parameters suggest that slope,
land-use, precipitation and forest were important determinants of
nesting habitat suitability. Conclusions: The most likely district
reported by the model for Woollyneck nesting habitat has not previously
reported nests which suggests additional survey effort in this region is
warranted. We recommend that priority should be given to conserve taller
trees close to settlements and cropland, and future studies should
consider the potential impact of climate change on nesting suitability
of this species.