Outcomes of wildlife rehabilitation vary by causes of admission for birds and mammals affected by human-wildlife impacts in southeastern Brazil

Abstract

Wildlife Rehabilitation Centres are essential for the care, recovery and potential release of wild animals, while also providing valuable information on the impacts of human activities on biodiversity. In this study, we analyzed 12 years of data (2012 to 2023) from the Wildlife Rehabilitation Centre of Associação Mata Ciliar (CRAS-AMC), located in southeastern Brazil. We investigated the monthly variation in the admission of birds and mammals, identified the main causes of admission, and evaluated how these factors influence the outcomes for the animals, including death, permanent captivity or release. A total of 23,441 bird records representing 329 species and 12,395 mammal records from 73 species were analysed. Among birds, the most common causes of admission were illegal trade and removal requests usually made by members of the public in relation to animals in urban areas, with or without injuries, while mammals were most often admitted due to requested removal from urban areas, dog attacks or vehicle collisions. Mortality was the predominant outcome for both birds and mammals, though outcomes varied according to cause, with higher mortality among animals admitted due to collision with vehicle or trafficking, and higher chances of release among those with minor injuries or mistakenly removed from the wild. These findings demonstrate the importance of long-term data collected by Wildlife Rehabilitation Centres to assess threats to wildlife, guide awareness campaigns and support preventive actions. Additionally, such data can inform improvements in the design and operation of current and future facilities. Strengthening these centres is critical for effective wildlife recovery and biodiversity conservation in Brazil, one of the most biologically diverse countries in the world and increasingly affected by anthropogenic pressures.