KnowraCrossbillCrossbillA finch in the genus Loxia, distinguished by bill tips that cross and help it extract seeds from conifer cones.BriefConnectCrossed bill: A bill whose upper and lower tips curve past one another in opposite directions. The defining adaptation wedges cone scales apart so the tongue can reach seeds.Red crossbill: A widespread North American crossbill with populations adapted to different conifer foods. Its diverse populations illustrate how one species can specialize on distinct cone types.Loxia: A genus of finches whose members have crossed bill tips adapted for opening conifer cones. Crossbill is the common name for birds belonging to this genus.Ecomorph: A form within a species whose traits are associated with a particular ecological niche. Crossbills with different bill sizes can represent forms suited to different conifer foods.Finch: A small to medium-sized seed-eating songbird in the family Fringillidae. Crossbills are finches whose bill shape departs sharply from the typical finch pattern.Conifer cone: The seed-bearing reproductive structure of conifers, built from overlapping scales. Crossbills prise open its scales to take seeds from within.Parrot crossbill: A large-billed Eurasian crossbill specialized for extracting seeds from spruce cones. Its deep, powerful bill suits the thick scales of its principal food cones.Carl Linnaeus: A Swedish naturalist who established the binomial system of naming species. Linnaeus formally described the common crossbill as Loxia curvirostra.Ecological speciation: The evolution of reproductive isolation through adaptation to different ecological conditions. Distinct crossbill feeding niches offer a case for testing whether ecological divergence drives speciation.Bullfinch: A stocky finch with a short, thick bill suited to seeds, buds, and fruit. Its robust but uncrossed bill contrasts with the crossbill’s cone-opening adaptation.Show all 26Linked from 3 pagesBeakBroader topic: Its unusual beak demonstrates a close match between form and feeding technique.BillBroader topic: Its unusual bill is specialized for prying open cone scales.Show all 3