An animal species’ diet constitutes the basic ecology of that species and is indispensable for understanding its ecological niche. Crows (Corvus corone and C. macrorhynchos) gather at communal roosts in winter and regurgitate indigestible portions of food as pellets on the ground under the roost. We used pellet analysis to determine crows’ diets and compared them between agricultural (Joetsu region, Niigata) and urban areas (Tokyo) in 2002 winter, The pellets were classified into plant animal and artificial matter. The major food substance in both areas was plant matter. The pellets collected in the Joetsu region were shaped like bullets and contained primarily seeds of Oryza sativa and Rhus spp. The pellets collected in Tokyo had loose texture and were flattened, and contained plant matter such as fruits and berries of trees and shrubs, Second in frequency to plant matter was artificia1 matter consisting of small pieces of white or transparent plastic usually used for garbage bags. Artificial matter also contained aluminum foil and paper, a1l of which are used for food wrappings, suggesting their association with food scraps. In this study, we discussed the utility of crow pellets for teaching food webs and the environmental issues such as garbage disposal.

From 2012 to 2021, bird surveys were carried out from Kyushu to Hokkaido, Japan, including a zoo, to find feather mites (Analgoidea Trouessart & Mégnin, 1884 and Pterolichoidea Gaud & Atyeo, 1978) from raptors including owls. In this study, we detected eight feather mite species as following: Glaucalges tytonis Dabert, Ehrnsberger & Dabert, 2008, Hieracolichus nisi (Canestrini, 1878), Kramerella bubonis (Lönnfors, 1937), Kramerella aprotuberantia Dubinin, 1953, Dermonoton longiventer (Mégnin & Trouessart, 1884), Petitota aluconis (Buchholz, 1869), Pseudalloptinus aquilinus (Trouessart, 1884) and Pseudalloptinus milvulinus (Trouessart, 1884).Two of the mite species, G. tytonis and Ps. aquilinus, were only sampled from bird hosts born in the zoo of Japan but they probably originated from oversea. The five of the eight species, Hi. nisi, K. bubonis, K. aprotuberantia, D. longiventer and Pe. aluconis were first reported in Japan. Among them, Hi. nisi was detected only from endangered bird host species Aquila chrysaetos (Linnaeus, 1758)(EN: Endangered). For the mite species, it is important to examine the status of their populations to consider the extinction risk in Japan, because they may be threatened with extinction simultaneously with the decline of the host populations in the future. Three species of mites, G. tytonis, D. longiventer, Hi. nisi were first reported from the hosts Bubo bubo (Linnaeus, 1758), Strix uralensis Pallas, 1771, Haliaeetus albicilla (Linnaeus, 1758), respectively. The Ps. milvulinus was also the first reported from the hosts Buteo japonicus Temminck & Schlegel, 1844 and A. chrysaetos.