Seasonal variation in community composition and distributional ranges of birds along a subtropical elevation gradient in China

Aim
Seasonal variation in community composition and species distributional ranges along elevational gradients remain poorly known but are essential to inform conservation. In this study, we aim to understand how species richness, community composition, and elevational ranges of montane birds change between the breeding and the non-breeding season.

Location
The east slope of the southern Gaoligong Mountains, Yunnan, southwestern China, elevational range: 700 - 3400 m a.s.l.; latitudinal range: 24°56´- 26°09´ N.

Methods
We compared bird species richness and community composition in nine 300-m elevational bands in the breeding (April - May) and non-breeding (December - January) seasons. We also calculated seasonal elevational shifts of 97 species with sufficient data recorded in both seasons and assessed how species’ traits influenced these shifts.

Results
Species richness declined in high and low elevations between the breeding and non-breeding season. The temporal beta diver...