Large Hawk-Cuckoo and Asian Koel, two species of tropical cuckoo, may be increasing in the Miyako Islands of Southern Japan

Abstract

We observed the occurrence of Large Hawk-Cuckoos Hierococcyx sparverioides and Asian Koels Eudynamys scolopaceus from 2015-2017 at the Oono Forest in Miyako Island, Okinawa Prefecture, Japan. Two Asian Koels (a male and a female) were present for more than two months during the breeding season of 2015, and this suggests that they may have attempted breeding, although there was no confirmed observation of reproductive behavior. These two species are increasingly recorded in Japan, which suggests that these species are expanding their distribution northward.