Interval of Remigial Molt of Two Wild Red-crowned Cranes<i>Grus japonensis</i> Breeding in Naganuma, Hokkaido, Japan

Abstract

Molts of remiges of two wild Red-crowned Cranes Grus japonensis were observed in Maizuru retarding basin, Naganuma, Hokkaido. The female (A1) started to first molt in May 2019 when she was 2-years-old, and then molted two years later in June 2021. The male (A2) molted first in May 2018 when he likely was 2-years-old, and then molted three years later in June 2021 when he was raising a chick together with A1. The exact flightless period was uncertain, however, it was 45–56 days in A1, and 51–63 days in A2.