Tree fruits consumed by Eophona migratoriain winter

From November 2009 to February 2011,yellow-billed grosbeak(Eophona migratoria)consuming fruits and seeds of 12 tree species in Nanjing city,the capital of Jiangsu province,was observed in order to understand its food habit in winter.Yellow-billed grosbeaks usually crushed and destroyed the hard pericarps or seed coats with its thick bills,then fed on the embryo and endosperm inside,thus acted as a seed predator.As some other frugivorous bird species also foraged these tree fruits,and dispersed their seeds,fruit predation by yellow-billed grosbeaks would not cause serious influence to the seed dispersal of those trees.Yellow-billed grosbeak often foraged in tree canopies in early winter,but later in deep winter,it mainly lived on fallen fruits on the ground under the tree canopies.E.migratoria could crush the hard pericarps such as nuts of Pterocarya stenoptera,and provided opportunities for those accompanying Eurasian tree sparrows(Passer montanus)to forage seed fragments on the ground.