Los Angeles County Public Health Department officials, after observing a 200 percent increase in the ground squirrel population in Palisades Park between February and June of this year, notified City staff last month that additional controls must be undertaken to reduce the population to acceptable levels.
A joint statement released by County officials and the City of Santa Monica said, “Regrettably, efforts begun in February to reduce and then manage the ground squirrel population in the park, including administering immunocontraceptives and educating the public on not feeding the squirrels, were not as effective as anticipated.”
To comply with the County directive, the City is contracting with Heritage Wildlife Management to do live-trapping of ground squirrels in several blocks of the park beginning in approximately mid-August, said Elaine Polachek, the City’s Open Space Manager. These squirrels will be euthanized offsite using carbon dioxide and taken to a wildlife rehabilitation facility where they will be fed to hawks and other wild birds being readied for return to the wild, where squirrels are their natural prey. The American Veterinary Association has deemed the use of carbon dioxide as an acceptable method of humane euthanasia of rodents.
Ms. Polachek expressed hope that the Heritage personnel could perform their work without interference from the people of Santa Monica, and thereby without any disturbance to the other animal life in the park.
While the pilot program begun in February did not produce the desired results in the short term, the City has found very promising research regarding the use of a single-injection immunocontraceptive vaccine. This research program was conducted by the USDA Wildlife Service and the California Department of Health Services. The study was conducted in a park portion of the Berkeley Marina that contains a variety of terrains; squirrels were trapped and injected with the vaccine that inhibits their sexual development. This research was conducted over two breeding seasons and was found to have been over 90 percent effective.
City staff, with assistance from the County Health Department, has been in discussions with USDA Wildlife Services regarding the conduct of a similar program in Palisades Park. This type of program could become a model for reducing the use of lethal controls on ground squirrels.
“The goal is not in any way to remove all ground squirrels from Palisades Park,” said Gail Van Gordon, County Public Health entomologist. “The intent is to reduce the number to a level that is acceptable for the safety of park users and pets and for the health of the squirrels. We join the City in asking well-meaning people to please refrain from feeding the squirrels. Allowing squirrels to naturally forage for food is a major factor in maintaining a healthy population in manageable numbers.”