Bird Lore: Red Crossbill

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The Red Crossbill is a nomadic, parrot-like finch that specializes in extracting seeds from pine, fir, hemlock, juniper, larch, and spruce cones. It lives in forests of the Northern Hemisphere around the world. It is a resident bird in all of the mature conifer forests of Washington. It can usually be seen in Edmonds each year, but its presence is highly irruptive as it follows the abundance of cone crops.

The status of the Red Crossbill is still debated in scientific circles as investigations of this finch continue. There are ten call types in North America and subtle differences in the Red Crossbill that are nearly impossible to discern in the field. Do the call types represent subspecies or different species? Recently one new species has been recognized in the forests of southeastern Idaho and has been named Cassia Crossbill. It is Idaho’s only endemic bird species.

Between January and March 2013, a small population of Red Crossbills foraged in the pines of Harbor Square. These pines are short enough that many birders were able to photograph the birds up close. LeRoy’s photos were taken at that location. Most Red Crossbill sightings in Edmonds are based on first hearing a flock calling while foraging high in Douglas firs. This finch is also seen from time to time at bird feeding stations.

Besides conifer seeds, the Red Crossbill will also eat tree buds, seeds of deciduous trees and weeds, as well as some berries and insects. It also feeds on road grit and salt. It offers regurgitated seeds to its young. The Red Crossbill forages in flocks and typically clambers over cones, often feeding upside down. Its crossed bill allows it to spread the scales of a cone and extract seeds. Because its biting muscles are stronger than the muscles it uses to open its bill, it places the tips of its slightly opened bill under a cone scale and bites down. The crossed tips of the bill then push the scale upwards, exposing the seed inside.

Timing and distribution of nesting is irregular. The Red Crossbill often breeds when cone crops are most abundant. It will nest at any time of year except mid- to late-fall. The male performs a flight-song display and will feed the female. The nest, built by the female, is on a horizontal branch of a conifer, well out from the trunk, and usually 10-40 feet above ground. It is a cup made loosely of bark strips, twigs, and grass, lined with finer materials such as grass, moss, lichens, and hair. The female incubates her 3-4 eggs for about two weeks. The male brings her food during this time. Both parents feed the nestlings. The young birds leave the nest about three weeks after hatching.

Almost 16,000 Red Crossbills have been banded in the U.S. since 1960. Only 48 have been recaptured. Of those, one recaptured and released during a 2014 Idaho banding operation was at least 8 years of age. Collective nouns for all finch species include charm, trembling, and trimming.

The U.S. population of Red Crossbills appears to be stable, but the greatest decline has happened in the Pacific Northwest between 1966 and 2015, according to the American Breeding Bird Survey. This was due to rapid deforestation. Clearcuts and young tree farms do not support the Red Crossbill. The global population is estimated at 20 million birds, with 25 percent spending part of the year in the U.S., 14 percent in Canada, and 3 percent in Mexico. For conservation purposes, it is considered to be a species of least concern.

You can hear calls of a pair of Red Crossbills here: http://www.xeno-canto.org/325224.

— By Carol Riddell

Carol Riddell manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.

4 Replies to “Bird Lore: Red Crossbill”

  1. I remember when that flock of crossbills hit Harbor Square. They were so intent on feeding that they did not mind us photographers. I keep hoping they will return.

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  2. Thanks, Carol. As always, I do enjoy your bird commentaries and the photos. I have seen an occasional crossbill at our small pine tree that is usually covered with cones. What a treat!

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