Why are crossbills invading Iceland? Investigating the eco-evo-devo of rapid adaptations to life in exotic tree plantations.

Objective

Human activity is reshaping Arctic ecosystems, as illustrated by extensive forest plantations in Iceland since the mid-20th Century. While the effects of nonnative afforestation on biodiversity remain under-studied, some species appear to thrive in such humanaltered habitats. A striking example of this is the Common Crossbill (<i>Loxia curvirostra</i>), a bird known for its extreme beak morphology that is adaptive for feeding on spruce cones. Crossbills recently established in Iceland by colonising plantations of nonnative pines with cones that the species haven’t coevolved with. This makes a unique model to investigate the paradox of why and how some species adapt to novel environments even when such species are specialists of a narrow range of resources. I propose that this paradox can be addressed with a comprehensive approach bringing together ecology and developmental biology. With ARCTICADAPT, I will use this approach to elucidate the invasion of common crossbills in Iceland. First, I will study the adaptations associated with the colonising success of crossbill using modern morphometrics of beak shape, diet analyses and geographic modelling. Second, I will unravel the global origin of crossbills in Iceland using population genomics. Finally, I will uncover the developmental process behind the rapid evolution of such adaptations with a developmentally informed study combining functional genomics and morphometrics. The project will include an expedition to Iceland to sample DNA, morphology and behavioural data, and a Secondment at the Netherlands Institute of Ecology for protocol development and genetic analyses. ARCTICADAPT will launch my career project of a long-term study to establish Icelandic crossbills as a powerful model to investigate the developmental bases of rapid adaptations. Understanding how developmental properties determine the ability of species to cope with habitat change will be crucial to halt biodiversity loss worldwide.