A Tennessee Warbler (Leiothlypis peregrina) captured in the web of a golden silk orb-weaver (Trichonephila clavipes)

Abstract

During migration, transient birds usually find themselves stopping in unfamiliar habitats in order to rest and refuel before resuming migratory flight. Here we document the first case, to our knowledge, of a Tennessee Warbler (Leiothlypis peregrina) entrapped in a spiderweb. The warbler's tarsus became caught in the mooring thread of a golden silk orb-weaver (Trichonephila clavipes) web and the bird was unable to free itself, resulting in death. While the role of spiderweb-related mortalities is likely minimal, they may represent a type of additive mortality that has been largely unconsidered during migration. Given the spatiotemporal overlap in the prevalence of spiderwebs and movement of migratory birds, researchers should document and report such anecdotal observations to determine the role spiders may play in mortality events during migration.