Insights Into the Ecology of a Widespread but Poorly Known Aerial Insectivore and a Theoretical Basis for Range Expansion Following Repeated Vagrancy Events

Abstract

ABSTRACT Over the course of the last two centuries, Northern Rough‐winged Swallows (Stelgidopteryx serripennis) have expanded their range across the North American continent but have remained a relatively poorly known species. In this paper, I discuss two aspects of their nature history that has received little attention. First, I document an instance of Northern Rough‐winged Swallows digging their own burrow, which was for the better part of the last century considered a behavior that was either lost or never occurred in the first place. Second, I review the natural history literature to document qualitative patterns evident in their expansion over the last two centuries. In doing so, I define three potentially useful concepts that can he applied to understand species' range shifts: an Expansion Chronology, which is a spatiotemporal map of a range shift; the concept of Vagrancy‐induced Range Expansion, where a species undergoes repeated movements outside of their typical geographic range (defined as vagrancy events), leading to the regular occurrence in a new region (e.g., regular overwintering or nonbreeding occurrences); and the concept of Vagrancy‐induced Long‐distance Dispersal, which is specifically expansion of a species' breeding range following repeated vagrancy events.

Keywords

• long‐distance dispersal
• nesting ecology
• northern rough‐winged swallow
• range expansion
• Stelgidopteryx serripennis
• vagrancy