A RETROSPECTIVE ANALYSIS OF MORBIDITY AND MORTALITY IN CAPTIVE BLUE-CROWNED LAUGHING THRUSHES (PTERORHINUS COURTOISI): 1998-2018.

The blue-crowned laughingthrush (BCLT) (Pterorhinus courtoisi) is a species of critically endangered passerine that is part of a Global Species Management Plan and experiences high mortality rates in some collections. Complete necropsy and medical records from 15 European institutions that housed BCLT between 1998 and 2018 were assessed to evaluate morbidity and mortality in the captive population. Medical records for 407 BCLT were received; a total of 191 morbidity events were recorded from 111 individual BCLT. The most common cause of morbidity was coccidial disease, including systemic isosporosis (30.4%, n = 58). Age was a significant factor contributing to mortality, with 53% of deaths occurring between 0 and 14 d old and 78% by 1 yr of age. The most common cause of death was trauma (22.8%, n = 31), followed by systemic isosporosis (22%, n = 30). Of the 343 deceased birds for which records were provided, 50.4% had a necropsy performed and 40.5% had histopathology carried out postmortem. Based on these findings, BCLT should be managed carefully to mitigate risk of trauma, and screening for isosporosis should be performed. Institutions should carry out standardized necropsies and histopathology on every BCLT that dies in their collection to elucidate the etiology of disease in this critically endangered species.