Driving forces behind the fluctuating growth of the number of successful nests in an inland population of white‐tailed eagles in Hokkaido, Japan

Abstract

This study aimed to describe the change in the number of successful nests of the white-tailed eagle, Haliaeetus albicilla, for 25 years along the Teshio River (100 km), Japan, which is a new habitat for this endangered species and identify factors driving the number of nests. The number of nests grew from two to nine. The logistic function fitted in well with the growth, and the capacity of the study area sustaining the successful nests was estimated at 6.5. The precipitation in January and April explained the deviation of the observed values from the model prediction. In particular, heavy rain in April was associated with low numbers. Forty-six nest remains were collected from 17 nest locations. Twelve genera of birds, six genera of mammals, and four