Satellite tracking documents individual migratory movements of the Rufous-chested Dotterel Zonibyx modestus

Shorebirds in the Southern Hemisphere remain poorly studied compared to their boreal counterparts, limiting our understanding of their migratory connectivity and population structure. Within the Americas, the Rufous-chested Dotterel Zonibyx modestus breeds in Patagonia and the Falkland Islands, and winters along the coasts of Chile, Argentina and Brazil. To provide the first baseline on migratory connectivity in this species, we tracked six individuals using Argos satellite transmitters deployed at a wintering site in central Chile (Itata River estuary) and a breeding site in southern Patagonia (San Gregorio). Patagonian birds remained close to their breeding areas or migrated to the north-east to winter along the central and southern Argentine coast. In contrast, both individuals wintering in central Chile migrated south along the Pacific coast to breed at high-elevation (over 800 m asl.), on islands and along fjords located in the Aysén and Magallanes regions, using a series of mainly coastal but also inland stopovers. Across regions, breeding areas were open, wind-exposed landscapes dominated by low shrubs and grasses, despite differences in elevation. These results indicate that individuals from different parts of the species’ range can follow distinct migratory routes, but the small sample size precludes inferences about population structure or separated flyways. Expanded tracking and genetic sampling are needed to evaluate the scale and consistency of these patterns in a poorly known Neotropical plover.