Size matters wintering ducks stay longer and use fewer habitats on largest Chinese lakes
Time:2021-05-10Source: 原创 Hits:
Meng, F., Li, H., Wang, X., Fang, L., Li, X., Cao, L. and Fox, A.D.,
2019. Size matters: wintering ducks stay longer and use fewer habitats
on largest Chinese lakes. Avian Research, 10(1), pp.1-8. (HQBN2716)
Evidence suggests that wintering waterbirds have become conspicuously
more concentrated at two largest lakes of the Yangtze River Floodplain,
East Dong Ting Lake (Hunan Province, 29°20′N, 113°E) and Poyang Lake
(Jiangxi Province, 29°N, 116°20′E), relative to other lakes, despite the
establishment of reserves elsewhere. While this relationship is likely
due to greater extent of undisturbed habitats in larger lakes, we
understand little of the drivers affecting individual behaviours behind
this tendency. We tracked wintering movements of three duck species
(Eurasian Wigeon Mareca penelope, Falcated Duck M. falcata and Northern
Pintail Anas acuta) using GPS transmitters, examining differences
between the two largest lakes and other smaller lakes in ducks’ habitat
use, duration of stay at each lake and the daily distances moved by the
tagged birds while at these sites. The Eurasian Wigeon and Falcated Duck
stayed five times longer and almost exclusively used natural habitat
types at the two large lakes (91‒95% of positions) compared to length of
stay time at smaller lakes, where they spent 28‒33 days on average
(excluding the capture site) and exploited many more different habitats
(including c. 50% outside lakes). Our study is the first to show that
shorter length of stay and more varied habitat use by ducks at small
lakes may contribute to explaining the apparent regional concentration
of numbers present of these and other species at the largest lakes in
recent years. This compares with their declining abundance at smaller
lakes, where habitat loss and degradation has been more manifest than on
the larger lakes.