Want to support nesting songbirds? Shoot for a minimum of 70% native plant cover in your landscaping, and 94% would be better, according to a recently published study by the University of Delaware’s Desirée Narango and others. For their study, the scientists chose Carolina chickadees as a representative suburban songbird. Homeowners across the southeastern U.S. delight to see them in our yards and at our bird feeders. Like most songbirds, chickadees provision their nestlings with insects from the landscape around their nest.

Study results show that baby chickadees reared in landscapes with less native vegetation are food-limited and much less likely to survive. So much so that the authors termed landscapes with less than 70% native vegetation as “food deserts” and “habitat sinks”. A habitat sink is a place with habitat sufficient to attract animals but insufficient to support their survival or the survival of their young. Habitat sinks are bad for a species because breeding pairs do not produce enough young birds to replace their parent’s generation. It would actually be better for the chickadees not to have that habitat available at all. Continue reading