Unparalleled Migration and Communal Roosting of Northern Roughwinged Swallows (Stelgidopteryx serripennis) in the Dominican Republic

Abstract

Although the Northern Rough-winged Swallow (Stelgidopteryx serripennis) typically winters in Mexico and Central America, recent observations in the Dominican Republic highlight the Caribbean Basin as a potentially important migratory stopover region. We quantified the spatiotemporal patterns of this species in the coastal wetlands of the Samaná Peninsula during mid-January 2019 and mid-March 2023. We recorded maximum flock sizes of approximately 3,000 individuals in January 2019, and 4,000 in March 2023. The January event involved a large westward flight at altitudes of up to 2,000 m, followed by a rapid descent to forage over mangrove wetlands. The March 2023 event was characterized by evening aggregations and communal roosting. Historical analysis of eBird records revealed that these two events alone (>7,000 individuals) exceeded the cumulative total reported for this species over a century across ten Caribbean and Mid-Atlantic islands. These exceptional aggregations confirm that the Dominican Republic may support massive transient flocks of this species, underscoring the regional importance of Caribbean wetland and mangrove mosaics for migratory aerial insectivores.

Citation

Arendt, W.J.; Tórrez, M.A.; Paulino, M.M. [et al.]. 2026. Unparalleled migration and communal roosting of Northern Rough‑winged Swallows (Stelgidopteryx serripennis) in the Dominican Republic. Cotinga. 48: 139-146.