A survey to the distribution of the Scaly-sided Merganser (Mergus squamatus) in Changbai Mountain range (China side)

In 2008 and 2009, we made continuous and repeated breeding surveys of the Scaly-sided Merganser (Mergus squamatus) in the Changbai Mountain range (China side), using a combination of rubber-boat drifting and walking. Each survey consisted of a census of breeding pairs in the spring and broods in the summer. A total of 1553 km in length of 17 river stretches were surveyed in four different river systems of the Yalujiang, Songhuajiang, Tumenjiang and Mudanjiang rivers. A total of 1354 individuals of the Scaly-sided Merganser were recorded during the both surveys. The breeding density for all the stretches surveyed over both years averaged 0.26 ±0.30 pairs per km; the population density in the spring averaged 0.75 ±0.88 individuals per km. According to our survey results, we estimated that the breeding population in the Changbai Mountain range was about 170 breeding pairs of the Scaly-sided Merganser. Three major breeding sites of this bird were found in the Changbai Mountain range in these surveys.