- Crossbill, Common Crossbill (British)
- Béc-croise des sapins (French)
- Pico cruzado (Spanish)
- The Red Crossbill is so dependent upon conifer seeds it even feeds them to its young. Consequently, it can breed any time it finds a sufficiently large cone crop, even in the depths of winter.
- Because this species can breed throughout most of the year, its molts and plumages vary more than those of other North American passerines. Juveniles hatched during summer molt only between late summer and late autumn (at the same time adults molt). Many (but not all) juveniles hatched earlier (from late winter and early spring) begin to molt 100-110 days after hatching and then again during the main molt period in the summer.
- A crossbill's odd bill shape helps it get into tightly closed cones. A bird's biting muscles are stronger than the muscles used to open the bill, so the Red Crossbill places the tips of its slightly open bill under a cone scale and bites down. The crossed tips of the bill push the scale up, exposing the seed inside.
- The Red Crossbill shows a great deal of variation in bill shape and voice, and it may in fact be composed of several different species. Eight different flight call types have been described north of Mexico, and birds giving each type have slightly differently shaped bills and prefer to feed on different tree species with differently sized cones.
- The oldest recorded Red Crossbill was a female, and at least 6 years, 1 month old when she was found in South Dakota, the same state where she had been banded.
Mature coniferous forests.
Conifer seeds, especially spruce, pine, Douglas-fir, and hemlock.
- Egg Description
- Whitish, with reddish streaks and splotches concentrated around large end.
- Condition at Hatching
- Helpless with sparse down.
Open cup of twigs, lined with grasses, lichen, conifer needles, bark shreds, hair, plant fibers, and feathers. Well concealed in dense cover on branches of coniferous tree.
Hangs on cones and extracts seeds with oddly-shaped bill. Feeds in flocks. Takes grit and salt from roads.
Red Crossbill is a global species. In the U.S., populations appear to be stable in most areas, though they may have experienced a decline, notably in the Northwest, between 1966 and 2014, according to the North American Breeding Bird Survey. Nomadic movements can make population trends difficult to assess, but Partners in Flight estimates a global breeding population of 20 million with 25% spending part of the year in the U.S., 14% in Canada, and 3% in Mexico. The South Hills Red Crossbill in Idaho is a distinct subspecies and is on the 2014 State of the Birds Watch List, which lists bird species that are at risk of becoming threatened or endangered without conservation action. Rapid deforestation in the Pacific Northwest has caused declines of Red Crossbill in that area. These birds were formerly common in Newfoundland, but they are now rare, possibly extirpated because of competition with the introduced Red Squirrel.
- Adkisson, C. S. 1996. Red Crossbill (Loxia curvirostra). In The Birds of North America, No. 256 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D.C.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- Partners in Flight. 2012. Species assessment database.
- USGS Patuxent Wildlife Research Center. 2015. Longevity records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.