Seasonal and interannual variation of the Black-necked Swan in the Caulin marine wetland, southern Chile

Seasonal and interannual variation of the Black-necked Swan Cygnus melancoryphus (Anseriformes: Anatidae) population in the Caulín marine wetland, Chiloé, southern Chile

By Jaime R. Rau

Laboratorio de Ecología, Departamento de Ciencias Biológicas y Biodiversidad, Universidad de Los Lagos, Osorno, Chile

Jaime A. Cursach

Fundación Conservación Marina, Puerto Montt, Chile

The global decline of waterfowl populations is a major concern, particularly for endemic species such as the Black-necked Swan (Cygnus melancoryphus), which faces threats like habitat loss, pollution, and climate change.

Pair of Black-necked Swans with cygnet by Febe van Tonder / WWT

This study examines seasonal and interannual variation in the abundance of this species at the Caulín marine wetland, Chiloé, Chile, from 2010 to 2023, using data from the eBird platform. Abundance trends and their correlation with the “El Niño” phenomenon were explored.

Results show a decreasing trend in the species’ abundance over the study period, with the highest concentrations recorded in spring and notable interannual fluctuations. No significant correlation was found with the El Niño Oceanic Niño Index (ONI). This study highlights the need for further research on the local changes that are affecting the abundance of waterbirds in marine wetlands in the region.

The full article can be found here