A report of infection in the crested ibis Nipponia nippon with feather mites in current Japan

The crested ibis Nipponia nippon Temminck, 1835 (Pelecaniformes, Threskiornithidae) is a wetland bird with a wide distribution throughout the Far East (Li et al., 2009). However, most native populations of this species have declined, mainly because of hunting activities and environmental destruction, except for a small area in China (Li et al., 2009). In Japan, the crested ibis was categorized as “Extinct in the wild (EW)” on the Red List of the Ministry of the Environment, Japan (Ministry of the Environment, 2002), when their wild population vanished. “Midori” and “Kin”, the last two reared individuals in the Sado Japanese crested ibis conservation center in Japan, died in 1995 and 2003, respectively, resulting in the complete extinction of Japanese individuals (Nishiumi, 2009; Yamagishi, 2009). Since 1999, seven individuals were transported from Yang Xian, Shaanxi Province, China (Lan et al., 2019), in order to breed and re-introduce the crested ibis in Japan, because the Chinese population was thought to be closely related to the Japanese population based on the similarity of mitochondrial DNA (Yamamoto, 2007). The transported Chinese individuals were bred in cages on Sado Island, Japan, for reproduction. Since 2008, 327 individuals of the crested ibis, which were offspring of the Chinese individuals, were released on a natural field on Sado Island, which they colonized to maintain their population. Therefore, the crested ibis is currently categorized as “Critically Endangered (CR)”on the Red List in Japan (Ministry of the Environment, Japan, 2019a, 2019b). Feather mites of the superfamilies Analgoidea Trouessart and Mégnin, 1884, Freyanoidea Koch, 1844, and Pterolichoidea Trouessart and Mégnin, 1884 are known bird parasites, which are thought to inhabit the flight feathers and feed on preen gland oil and material trapped on it