Wetland biologists and others involved in managing lands with associated wetlands have been notified by the Department of Land and Natural Resources' Division of Forestry and Wildlife (DOFAW) of a recent avian botulism outbreak affecting waterbirds on Maui. In just over a week, 67 birds have been found dead at Kanaha Pond Wildlife Sanctuary in Kahului including Hawaiian Stilt, Hawaiian Coot, and Hawaiian Ducks of adult and juvenile stages. The paralytic disease has killed adult birds on their nests, also causing the eggs to be lost.
Because botulinum toxin can be produced in most wetlands, and transported to new wetlands by dead or dying waterfowl, landowners and managers, both public and private, are being asked to frequently survey their wetlands for sick and/or dead birds, remove any dead or dying birds from the wetland, and contact local DOFAW biologists for guidance. Earlier this year a botulism outbreak in Hanalei, Kauai resulted in over 300 sick and dead birds being collected by USFWS refuge staff. Additionally, numerous other botulism fatalities have also been reported at wetlands throughout the state.
Botulism is a paralytic condition brought on by the consumption of a naturally occurring toxin produced by the bacterium Clostridium botulinum. It is an intoxication rather than an infectious disease. Botulism, type C is commonly found in Hawaiian soils and is NOT dangerous to humans. Particular environmental conditions in wetlands will sometimes allow this bacterium to produce botulinum toxin; the toxin is then accumulated in aquatic invertebrates. It is consumption of these toxic invertebrates by waterfowl that leads to mortality.
In Hawai'i, birds commonly affected include waterfowl frequenting wetlands such as our endangered Hawaiian coots, Hawaiian ducks, Laysan ducks, Hawaiian moorhen, Hawaiian stilts, Black-crowned night- herons, and various migratory waterfowl and shorebirds. The U.S. Geological Survey (USGS) National Wildlife Health Center Honolulu Field Station (NWHC-HFS) has been working closely with the US Fish and Wildlife Service and the State of Hawaii DLNR to investigate and confirm botulism as a cause of waterfowl mortality in Hanalei and Kahului. The NWHC-HFS provides technical assistance to federal, state, municipal, and non-governmental organizations on wildlife health related matters in Hawai'i and the Pacific.
The public can help by reporting deaths of waterbirds to the District DOFAW Office on your respective island. On private lands individuals are asked to take the above mentioned recommended wetland management actions to prevent further impacts of this fatal disease.
DOFAW Administration Office, Honolulu (808) 587-0166
O'ahu Branch, Honolulu (808) 973-9778
Kaua'i Branch (808) 274-3433
Maui Branch (including Moloka'i, Lana'i, and Kaho'olawe) (808) 984-8100
Hawai'i Branch (Hilo Office) (808) 974-4221, (Waimea Office) (808) 887-6061
USGS - National Wildlife Health Center, Honolulu Field Station, (808) 792-9520, (808) 792-9521
or (808) 792-9523.