Landscape-dependent response to predation risk by forest birds

Knowing how forest loss and associated fragmentation actually impact individual birds is essential to our understanding of consequences at the population level. We conducted a landscape-level experiment to test whether deforestation affects the trade-off between foraging, and antipredatory behaviour of black-capped chickadees (Poecile atricapilla) in 24 landscapes (range 8-88%, forest cover, 500-m radius) during two winters. At field-forest edge in the centre of each landscape, we used the maximum distance Ventured into the open by flocks to get sunflower seeds placed on the snow-covered fields, as it measure of risk-taking. In the more deforested landscapes. chickadees ventured farther (LIP to the maximum of 40 m) into the open. Edge density and proportion of conifers in the forest had no influence on risk-taking. However. where ad libitum food was available for a few weeks prior to the experiment (in 12 of the 24 landscapes), chickadees ventured four meters or less away from the forest edge. regardless of the level of deforestation. We conclude that landscape deforestation increases energy stress, which in turn promotes risk-taking. and may therefore increase winter mortality through greater exposure to predators.