RISK FACTORS FOR MORTALITY IN BIRDS OF PREY UNDERGOING REHABILITATION IN SOUTHERN BRAZIL

Abstract

As top predators, birds of prey play a vital role in maintaining ecological balance, making their conservation essential. This retrospective study examined risk factors influencing the release or mortality of raptors treated at three rehabilitation centers in southern Brazil. Of 1,035 raptors admitted, Strigiformes were the most common, particularly Megascops choliba (tropical screech owl). Most admitted birds were adults (46.57%) admitted during the Southern Hemisphere's spring (36.91%). The musculoskeletal system was the most frequently affected (44.84%). Risk factors for mortality or euthanasia included age, with adults more likely to die than chicks. Raptors with one body system affected were 17 times more likely to die or be euthanized than those with none, and this increased to 62 times with two systems affected. Respiratory injuries had a higher fatality rate compared with other systems. Time in captivity was positively correlated with release rates; raptors treated longer had a 0.98 greater chance of being reintroduced into the wild. Compared with younger birds, the prognosis was worse for adult raptors admitted with two affected body systems. These results support veterinarians in rehabilitation centers by aiding decision-making and strengthening conservation efforts.