White-winged Crossbill

Like most crossbills, the White-winged is irruptive, meaning that it moves around the landscape in concert with changing food supplies. Its preferred foods are the seeds of spruce and larch, and perhaps because of this it has a more northerly distribution. The core of its range extends from Alaska to eastern Canada, with less regular breeding along the northern tier of states in the Rocky Mountains, Great Lakes, and Northeast. Here in New Hampshire, they are most likely to be found nesting from the White Mountains north, and in the western highlands when cone crops there are good.

Breeding can occur at any time of year as long as there are cones available, and seeing the bright pink males singing at the tops of spruces on a snowy winter day is a truly memorable experience. But like all crossbills, they need to wander when cones are scarce, and this is when they appear elsewhere in the state. During irruptions they will feed on other seeds, particularly those of pines, and will only stay in a location while the food lasts. Then they’ll wander off somewhere else until a good cone crop prompts them to settle down to breed once again.

Given their penchant for conifer cones, we don’t think of crossbills as tropical birds, but both Red and White-winged have made inroads into Latin America. In the case of the latter, wayward individuals colonized the Caribbean island of Hispaniola sometime in the last 500,000 years. From this founder population a whole separate species evolved – the Hispaniolan Crossbill – which resembles its ancestor except for having a heavier bill. Because the only conifer on this island is a pine, a larger bill is needed to extract seeds from sturdier cones. Hispaniolan Crossbill populations fluctuate in response to pine crops, but don’t leave the island simply because there is nowhere else to go.