Necropsy findings for bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos) found dead in New York from 2000 to 2015

In the northeastern United States bald eagle (Haliaeetus leucocephalus) populations were reduced by habitat loss, human persecution and nest failures attributed to DDT contamination of the food web. In 1970 only one active but... [ view full abstract ]

In the northeastern United States bald eagle (Haliaeetus leucocephalus) populations were reduced by habitat loss, human persecution and nest failures attributed to DDT contamination of the food web. In 1970 only one active but unproductive nesting pair was known to remain New York. Fostering and hacking programs added 198 eagles between 1976 and 1988 with many of the hacked eagles remaining or returning to NY to nest. By 1988 there were 10 documented nesting pairs which has subsequently increased to 254 documented nesting pairs in 2014. In an effort to document mortality factors for eagles, and as part of our routine wildlife disease surveillance program, all dead eagles found in NY were submitted to NYSDEC Wildlife Health Unit for necropsy to determine cause of death. All carcasses (regardless of postmortem condition) were examined by gross necropsy and gross findings determined when chemical analyses, histology, virology and/or bacteriology testing were pursued in order to reach a cause of death determination. Standard necropsy procedures included (where possible) morphometric measurements, descriptions of postmortem condition and gross lesions, and organ tissue collection for laboratory testing or archive. We examined 315 eagle carcasses between 2000 and 2015. Trauma (n=157), including motor vehicles and trains, comprised half of the mortalities. Additional mortalities were attributed to lead poisoning (n=38), conspecific inflicted trauma (n=33), and electrocution (n=24). Illustrations of common gross pathologies associated with different causes of death will be presented and discussed. Although eagles appear to be recovering in NY they continue to face anthropogenic mortality sources that could potentially limit future populations.