Vessels as an opportunity to track vagrant non-marine birds in the southwestern South Atlantic

Abstract

Records of non-marine birds over the ocean are not limited to waterbirds, but include landbirds and other bird groups. Sometimes, non-marine birds make use of vessels as platforms for rest and refuge. Here, we report observational and photographic records of landbirds and egrets obtained aboard seismic vessels operating in the Argentinean continental shelf and its continental shelf break. In 2018-2019, we made a total of 16 records of 21 individuals of 12 species of landbirds and 1 egret. Ten of these species were recorded for the first time in these waters. We report total duration of vessel permanence, which ranged from a few minutes such as the European Starling (Sturnus vulgaris) to 10 d for the White-banded Mockingbird (Mimus triurus). We highlight the record of a single White-browed Ground-Tyrant (Muscisaxicola albilora) individual, 700 km from its nearest continental record, and the novel feeding behavior of a Correndera Pipit (Anthus correndera) observed feeding on polyurethane foam. We encourage all professional and amateur ornithologists aboard vessels to collect and report records of non-marine birds, which may contribute to our understanding about the use of vessels as platforms of opportunity for resting, sheltering, and feeding purposes. Of particular interest are records of species that are not migratory, that do not normally make use of the seascape along their migration routes, and that may have been blown away to sea by storms or strong winds.