Niche modelling reveals conservation challenges and priorities for the threatened Pampas Meadowlark in South American agroecosystems

Analysing changes in the distribution and available habitat of an endangered species is key for understanding population dynamics, assessing threats and prioritizing actions for conservation strategies and areas to apply them. This is especially relevant in rapidly changing ecosystems subject to agricultural pressures, such as the South American Pampas. Here, species are experiencing the effects of habitat modification and fragmentation, as is the case for the Pampas Meadowlark Leistes defilippii , a severely threatened and declining bird species. Here we quantify, characterize and describe the historical contraction of Pampas Meadowlark habitat, and analyse its current distribution patterns to assess habitat fragmentation and current habitat occupancy, using Maxent ecological niche models. The selected models for suitable habitat show a 91% reduction in total area, as well as an increased degree of fragmentation, and a 98% decrease in mean patch size. Comparing historical (1850–2009) and recent (2010–2024) models shows that a higher proportion of occurrences are now associated with non‐suitable habitat. When analysing the recent model for suitable habitat in relation to the species' occurrences, a single population core is detected in Uruguay populations, embedded in a matrix of mostly suitable habitat. In contrast, there are three different core areas in Argentina, one of them highly disconnected from the other two, separated by areas of low habitat suitability. These findings highlight the critical conservation status of the Pampas Meadowlark and its habitat and identify key areas for conservation. In particular, the results show the effects of declining habitat quality and connectivity as constraints that should be addressed through conservation and restoration efforts at the local and regional scales in these key areas. In addition, the scarcity of protected areas in the species' range is a major concern, especially considering the existence of nearby Key Biodiversity Areas that have been designated mainly for Pampas Meadowlark populations.