Morbidity and mortality in free-living raptorial birds of Northern California: a retrospective study, 1983-1994

Abstract

A 12-year (1983-1994) retrospective study was conducted to determine the causes of morbidity and mortality in free-living raptorial birds of northern California. Of the 409 birds in- cluded in this study, 58% died of traumatic injuries and 30% died of infectious disease. The most frequent presenting signs were fractures, recumbency, shock, suboptimal weight, and dehydration. Although 30% of these raptors were in good nutritional condition, nearly 50% either were in fair condition or were emaciated. Pathologic lesions found in a few raptors (0.8%) indicated an under- lying disease (eg, tuberculosis) was present before the birds succumbed to an acute, lethal, traumatic incident.