Coordinated response and recovery efforts at Smith and Bybee Wetlands Natural Area limited the impact of a recent disease outbreak of avian botulism – saving the lives of thousands of migratory birds.
The lakes were closed to the public during the outbreak, which is now over. Avian botulism does not present a health risk for humans and, due to the completion of protection efforts, the lakes are open for paddlers to enjoy once again.
Avian botulism is a natural toxin often present in wetlands. However, the lengthy period without rain this summer, combined with warm fall temperatures, contributed to an unusually high level of the toxin. Even healthy, adult birds that would normally survive exposure to this type of botulism were affected. The concentration is now at a normal and safe level for the many birds that use these wetlands at this time of year.
During the past eight weeks, Metro collaborated with the Oregon Department of Fish and Wildlife, the U.S. Department of Agriculture Wildlife Services division, the Port of Portland and the Audubon Society of Portland to remove approximately 3,000 dead or dying birds, mostly green-winged teal ducks.
Since birds spending even a short time on the lakes were affected, Metro and its partners diverted healthy birds away from the area using air cannons and auditory frightening devices provided by the Port of Portland and the Department of Agriculture. Without action to move the birds off the lakes, it was anticipated that thousands more would have died, including several species with declining populations.
"In over 30 years of working with wildlife, this was by far the most impressive effort of cooperation and collaboration among regional wildlife conservation partners I have ever experienced,” said Katy Weil, a senior analyst at Metro who managed the day-to-day recovery efforts. “It takes very special people to bury so many once-healthy birds, find innovative ways to contain and treat the live ones that could be treated, travel through thigh-high heavy mud while wearing chest waders in 90-degree weather – all while using large, ear-protecting head gear as air cannons fired around everyone every three to five minutes."
The Audubon Society of Portland accepted sick birds and provided supportive care while the botulism worked its way out of the birds' systems. More than 100 recovered birds have been released back into the wild on Sauvie Island and were able to continue their migration.
"The rehabilitation effort was very intensive. After the animals came in to the center, they received fluids and were force fed up to five times a day. We recruited an extra staff member and three extra volunteers a day to help. All in all we had about an 80 percent success rate," said Lacey Campbell, Audubon Wildlife Care Center operations manager, who helped treat and lead the long term care for the birds.
Watch Metro park ranger Kristina Prosser release birds into the wild
Kristina Prosser releasing birds from oregonmetro on Vimeo.