Wildlife advent calendar: Day 16: Common crossbill
From just a quick glance of this fellows beak you can tell how this bird got its name. This beak shape helps the crossbill to extract the conifer seeds that they feed on from their cones. Crossbills are birds that are well know for their dramatic population swings, some years they will be present in very large numbers and some years you will barely see them. Their diet consists almost exclusively of conifer seeds and so they are heavily reliant on a good crop, particularity over winter.
They are present in the UK throughout the whole year but if there is not enough food on the continent then they will flock over here in large numbers. In years of a major irruption (a sudden upsurge in numbers) you are very likely to see groups of these birds on conifer trees in the Scottish highlands, the Norfolk coast, the New Forest and the Forest of Dean.
Image taken from Flickr user Stefan Berndtsson
The RSPB website