Crossbills are the nomads of the boreal forest.
They visit the territory regularly, and even breed here, but these small birds are something of an enigma. You never know where they might turn up next. Like other finches, crossbills are seed-eaters. When they run out of seeds in one area, they just move on, travelling for thousands of kilometers if necessary. Sometimes, in what are called invasions or irruptions, Crossbills show up in huge flocks in unexpected places.