Birds of Two Oceans? Trans-Andean and Divergent Migration of Black Skimmers (Rynchops niger cinerascens) from the Peruvian Amazon

This study reveals the first documented trans-Andean migration for any bird breeding in lowland Amazonia, challenging long-held assumptions about the impassable Andean barrier. Using satellite telemetry, researchers tracked Black Skimmers (Rynchops niger cinerascens) from the Manu River in Peru, demonstrating their ability to cross the high Andes and migrate along the Pacific Coast. One skimmer completed a full round-trip migration, traveling over 18,000 km from its breeding site in Peru's lowlands to the temperate Gulf of Arauco, Chile, for the austral summer—a reverse seasonal pattern for tropical-breeding waterbirds. The findings also highlight divergent movement patterns among individuals, with one skimmer migrating over 1,800 km southeast before transmissions ended. This research sheds new light on the complex seasonal movements of Amazonian birds and their adaptation to diverse landscapes.

Davenport, L. C., Goodenough, K. S., & Haugaasen, T. (2016). Birds of Two Oceans? Trans-Andean and Divergent Migration of Black Skimmers (Rynchops niger cinerascens) from the Peruvian Amazon. Plos One, 11(1), e0144994. https://doi.org/10.1371/journal.pone.0144994