The breeding biology and cone size selection of crossbills was studied mainly during 1995 to 2002 at Abernethy Forest, Scotland, an ancient native Scots pine Pinus sylvestris wood, where only a single ...

Most birds have bills with tips that come together when the jaws close. But not crossbills — hence their common name. The crossed bill tips are so unusual that they once were sometimes mistakenly ...

Crossbills are appropriate birds for the Christmas season. There are two species-red crossbill and white-winged crossbill. Both qualify as symbols of Christmas. Both are red overall. The white-winged ...

You are able to gift 5 more articles this month. Anyone can access the link you share with no account required. Learn more. In the last column, I wrote about the unusual bills of crossbills. These ...

In a kind of post-workout glow, male crossbills that work harder when flying will grow redder plumage. The findings reveal that the processes that generate red feather pigments in the birds may be ...