Research History

Thomas et al. 1998: USGS National Wildlife Health Center
  • Investigation of eagle deaths from DeGray Lake, AR
  • Documented unique myelin lesions in eagles
The following video is a segment from the Arkansas Public Television "Saving the Eagle" produced in 1998. Researchers from the Wildlife Health Center suspected a toxin was involved with AVM lesion development and bird deaths. It is interesting that the camera pans a thick bed of Egeria densa growing in DeGray Lake, Arkansas.



Rocke et al. 2002: USGS National Wildlife Health Center
US Fish and Wildlife Service

  • Established that AVM disease occurs only at specific lakes
  • Demonstrated that birds could get sick within 5 days of release onto an AVM lake
  • Documented that AVM disease only occurs during late fall and winter
Fischer et al. 2003: Southeastern Cooperative Wildlife Disease Study
  • Transfer of AVM from infected coot tissue to red-tailed hawks
  • Established food chain link between coots and eagles
Birrenkott et al. 2004, Lewis-Weis, et al. 2004: Clemson University Department of Forestry and Natural Resources
South Carolina Department of Natural Resources
Southeastern Cooperative Wildlife Disease Study
  • AVM lesions in mallards fed hydrilla from AVM site
  • Established food chain link between hydrilla, waterbirds and eagles
Wilde et al. 2005: South Carolina Department of Natural Resources
Clemson University Department of Forestry and Natural Resources
  • Field correlative study of hydrilla, cyanobacteria, and mallards
  • Established food chain link between cyanobacteria, invasive plants, and waterbirds
Wiley et al. 2009: Clemson University Department of Forestry and Natural Resources
South Carolina Department of Natural Resources
Southeastern Cooperative Wildlife Disease Study
NOAA: Center for Coastal Environmental Health and Biomolecular Research
  • Toxin extraction and testing on mallards and laboratory cell lines
  • Established nuerotoxin source is hydrilla and associated cyanobacteria