Duck Die-Off in the Ballona Wetlands

International Bird Rescue (Bird Rescue) is responding to a possible botulism incident on the Ballona Creek in Los Angeles, CA that has already resulted in the death of over 60 Mallard Ducks. 19 live Ducks and an American Coot (and two pelicans that were not a part of the incident – one tangled in fishing line, and the other emaciated) were captured and brought to International Bird Rescue’s Los Angeles Wildlife Center; 5 of the Ducks later perished.

Botulism is a condition brought on by the consumption of a naturally occurring toxin produced by the bacterium Clostridium botulinum. Usually, the first sign of this sickness involves partial paralysis of the birds. Early stages might show only the nictitating membrane, or third eyelid, being paralyzed, followed by larger muscle groups. Ultimately, the ducks are unable to move and drown.

Botulism outbreaks affect many water birds species, especially waterfowl, every year in summer and fall when wetlands are dryer and there are large concentrations of birds. The toxin can be passed on through ingestion of maggots from decaying bodies. These events can be managed by picking up all dead birds, and collecting affected live ones on a daily basis. Ducks with botulism respond well to an aggressive fluid therapy treatment. Bird Rescue’s typical release rate is from 80% to 90% if the birds are captured treated in time.

Since this is a naturally occurring phenomenon, there is little that can be done to prevent it, but International Bird Rescue will mitigate the effects by having a proactive search, collection and rescue system in place.