2019 Volume 31 Issue 1_2 Pages 1-9
In Shimokita Peninsula, Aomori Prefecture, northern Japan, the two types of Common Crossbills with different flight calls that lived temporarily in a pine forest from winter to spring in 2017/2018. One is Crossbills of the Shimokita population that inhabits all year round and reproduces there (we call them ‘Resident type'), and the other is visitor from the unknown place (‘Ping-Ping type'). The resident type has been observed and ringed since 2006, we are accumulating their morphological data. Compared six morphological traits between 16 Ping-Ping type birds and 88 Residents, culmen length and weight were biased. Linear discriminant analysis also showed contributions of the two traits to separate two types. Resident type crossbills had relatively shorter culmen and light weight, whereas Ping-Ping type had longer culmen and heavy weight. The difference of culmen would be reflect to the difference regular diet, i.e. cone of conifer species in breeding site. Heavy weight of Ping-Ping types might be cause fat accumulation and building muscle in pre-migration.
