The coastal breeding habitat of Bank Swallows (Riparia riparia) in an Atlantic Canada National Park: assessing habitat use in relation to availability

Abstract

Understanding bird habitat selection has become a priority in conservation, particularly for bird species facing long-term population declines. The Bank Swallow ( Riparia riparia (Linnaeus, 1758)), a species whose eastern distribution limit is in Atlantic Canada, declined by 98% between 1970 and 2011, prompting its listing as a threatened species in 2017. Its decline is hypothesized to be due in part to habitat loss and, hence, this study aimed to identify critical habitats within a protected area along Prince Edward Island. We used two types of survey to examine the availability and use of three breeding habitats: dunes, glacial till, and sandstone cliffs. A goodness-of-fit test revealed that the habitats were not used in proportion to their availability. Among them sandstone cliffs and, to a lesser extent, till cliffs were used significantly more than expected (i.e., selected). Instead, sand dunes were used less (i.e., avoided) as a breeding habitat. These results suggest that Bank Swallow selection is driven by characteristics associated with the sandstone and till habitats, and more attention and possibly protection should be given to them. Further studies should also explore whether similar patterns of selection are evident in the region’s historical records and in similar coastline areas.