Common crossbills (Loxia curvirostra) and their relatives are nomadic birds that follow conifer cone crops across Europe. Understanding their welfare during irruption years illuminates the challenges of their boom-bust ecology.
The welfare challenge of crossbill ecology is food security — flocks must locate productive cone crops or face starvation. Irruption birds arriving in Britain face unfamiliar habitat and uncertain food resources. Mature conifer forests with diverse species providing staggered cone crop timing offer the best welfare buffer. Climate change is altering cone crop phenology and potentially decoupling crossbill movements from food availability.