The pine grosbeak (Pinicola enucleator) is a large finch that inhabits the boreal forests and open coniferous woodlands of North America, Europe and Asia. Pine grosbeaks are plump-chested birds with a broad, curved bill. They are sexually dimorphic birds—males and females differ markedly in their appearance. Male pine grosbeaks are pinkish-red (on their head, breast, back and rump) with dark brown wings and tails. Female pine grosbeaks are yellowish-olive (on their head and rump) and have a gray back and belly, and dark brown wings and tail. Both sexes have two white wingbars.
Pine grosbeaks vary in size across their range. Wing and tail length, for example, tend to be greater in the western parts of North America when compared to eastern regions. Of course, that trend is a general one to which there are exceptions. The pine grosbeks that live on Queen Charlotte Island off the coast of British Columbia are the smallest of all pine grosbeaks, despite being in the western part of North America.
The total range of the pine grosbeaks is extensive but in North America, some populations of pine grosbeaks breed in the coniferous forests of the Rocky Mountains while others breed in the rain forests that lie along the coasts of Alaska and British Columbia.
Pine grosbeaks do not migrate extensively. Their movement is driven mostly in response to population density and the availability of food. In the mountains, populations of pine grosbeaks move to lower elevations during the winter. During the winter (non-breeding) season, North American pine grosbeaks occasionally migrate to parts of southern Canada and the northern United States.
The diet of pine grosbeaks consists almost entirely of plant matterial. Pine grosbeaks eat the buds, seeds, and fruits of a variety of trees and shrubs including spruce, pine, juniper, elm, mountain ash, maple, and crabapples. Young pine grosbeaks have a more varied diet than adults—young consume some plant material but most of their food intake consists of insects and spiders.
Little is know about the breeding habits of pine grosbeaks. Female pine grosbeaks start building nests in late May and build only one nest per season (males do not help construct the nest). They build their nest in dense foliage often near the trunk of a tree and between 2 and 4 meters off the ground. Pine grosbeaks usually lay 3 or 4 eggs in a clutch and incubation is between 13 and 14 days. The female incubates the eggs alone. After the young birds hatch, both parents feed them with regurgitated insects and plant matter.
Pine grosbeaks are gregarious birds that tolerate other birds in the flock well and display little aggression towards one another. Of course, during the breeding season, that all changes and pine grosbeaks (especially males) become fiercely territorial. Pine grosbeaks are often described as unwary or fearless birds.
Pine grosbeaks have a song that consists of a sequence of clear, flute-like notes that sound like a warbling "tee-tee-tew". They use their song during courtship to establish territory and to maintain pair bonds. They also use several other calls including an alarm call to warn of predators such as raptors, a food-begging call used when a female is fed by a male and a flight call that is thought to promote flock formation and cohesion.
Scientists do not know a great deal about the conservation status of pine grosbeaks. The main threats pine grosbeaks face are thought to include collisions with moving cars and habitat degredation (in both breeding and wintering areas).
- large finch
- sexually dimorphic
- wings have two white wing bars
- conical bill with upper mandible
- overlaps lower mandible
- limited migration
Adkisson, Curtis S. 1999. Pine Grosbeak (Pinicola enucleator), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/456