A reassessment of the Pampas Meadowlark Leistes defilippii: Evidence for Critically Endangered status and the urgent need for action

Abstract

The Pampas Meadowlark Leistes defilippii is a grassland specialist endemic to south-eastern South America, currently listed as ‘Vulnerable’ at the global level. However, available information on its distribution and population size is outdated or inaccurate, underestimating its risk of extinction. This study provides the most comprehensive reassessment of the species’ conservation status to date. Estimates of population size, Extent of Occurrence (EOO), and Area of Occupancy (AOO) are updated. The species’ status is evaluated using both the International Union for Conservation of Nature (IUCN) Red List and the Green Status frameworks. Results indicate an alarming decline in population size of over 80% across the last three generations. The current population is estimated to be between 1,460 and 2,057 individuals, with 90% concentrated in a single subpopulation in Argentina. The EOO has shrunk by 92% compared with previous estimates, and the AOO is now only 8% of the EOO. The species meets the thresholds for the IUCN ‘Critically Endangered’ category under criteria A and C. The Green Status assessment identifies the species as ‘Critically Depleted’, with a Species Recovery Score of 4% and a Conservation Gain of only 2%, highlighting its limited recovery potential even under current conservation scenarios. Our findings indicate that the Pampas Meadowlark is in critical condition and urgently requires an update in its status on the IUCN Red List. Immediate conservation actions are needed, including habitat protection and restoration, long-term monitoring, and the establishment of protected areas within its remaining range. This case exemplifies the need for up-to-date data in guiding effective conservation responses for threatened grassland species in South America. This reassessment underscores the urgent need to reassess the species’ global status and to invest in ambitious conservation strategies to prevent its extinction.