Red Crossbill

• The chicks hatch with a straight bill: it only crosses over after a few weeks, when they start needing it to open cones.
• It has an oesophageal diverticulum, a kind of pouch in the neck, where it stores food so as not to spend energy searching for it when the weather turns.
• Because pine seeds are hard to digest, it takes in a great deal of salt and comes down to forest tracks for the salt spread against ice.

Skeleton type

Vertebrate - internal bony skeleton (bird)

Habitat & environment

Woods of pine, fir, larch and spruce, from sea level to about 2,000 m. In Spain it is found mainly in the eastern half, from Málaga to the Pyrenees, as well as the Cantabrian Mountains and the Sistema Central

Size at birth

The chicks' mandibles are straight at hatching and only curve and cross a few weeks later

Sexual maturity

12 months

Gestation / incubation

13 days

Litter / clutch size

3-5 eggs. It can breed in almost any month of the year depending on the availability of pine seeds, and usually starts very early, in February or March

Sources consulted: SEO/BirdLife (ficha y III Atlas de las aves en época de reproducción en España); IUCN Red List; Asturnatura; Alonso et al. 2006, Ardea 94; Alonso y Arizaga 2017, Munibe 65; Jiménez et al. 2012; Bañuls-Patiño 2015, Atlas de las aves nidificantes de Alicante

Best time: All year round, though its presence is erratic: it is nomadic and moves in step with the cone crops