Changes in South American migratory sheldgeese distribution associated with climate change

Abstract

Climate change is affecting many species´ geographical distributions, by reducing ranges due to the loss of climatically suitable areas or enabling expansion into areas that become suitable. In southern South America, Patagonia has experienced notable changes in temperature and precipitation over the past 60 years, with significant impacts on its ecosystems. We assessed the potential impact of climate change on migratory sheldgeese distribution, a group of threatened birds that rely on Patagonian meadows, and used them as a proxy for broader climate change effects on other species inhabiting the same region. We compiled occurrence records from GBIF and citizen science platforms to model sheldgeese distributions using species distribution models. We compared current conditions with projections for two future periods, representing short-term and long-term scenarios, under both optimistic (SSP2–4.5) and pessimistic (SSP-5–8.5) Shared Socioeconomic Pathways. We found that climate change will affect sheldgeese distribution in different ways. In general, sheldgeese are projected to shift southward and to higher elevations, which will also modify the overlap among species. The upland and the ashy-headed goose are expected to lose part of their ranges in the long term, with few new suitable areas projected. In contrast, the critically endangered ruddy-headed goose is projected to expand its range southward. However, once it reaches the continent´s southern limit, it may lose the northern portion of its distribution, resulting in an overall range reduction. Our results contribute to understanding how climate change may modify the distribution of these threatened species pushing them toward the southern edge of the American continent.