Natural and anthropogenic causes of mortality in wild birds in a wildlife rehabilitation centre in Northern Portugal: a ten-year study

Capsule: A ten-year study of the causes of mortality in birds brought to a wildlife rehabilitation centre in Portugal, reveals that most deaths were due to trauma. Aims: This study aims to identify the main causes of morbidity and mortality in wild birds admitted to a wildlife rehabilitation centre in Northern Portugal, from 2008 to 2017. Methods: A total of 6058 records of admittance and necropsy were examined. Results: In the 24 orders present in the study, the most commonly reported were the Charadriiformes (34.1%) and Passeriformes (28.7%). The majority were adult individuals (80%) and most admissions were in the summer (43.1%). The main causes of admission were birds being injured (57%) and orphaned (18.3%). Trauma was also the most important cause of death (57%), followed by predation (1.6%) and collision with buildings (1.6%). The non-traumatic causes of death (2606, 43%) were mainly of unknown origin (22.2%) and infectious diseases (10%). Conclusion: The data analysed in our study allowed us to conclude that the main causes of morbidity and mortality of the birds admitted was due to trauma. This kind of study can provide useful information on population and ecosystem health to inform conservation practices.