Barn Owls Are Effective Vermin Catchers
Andrew Lasken, co-director of CLAW (Citizens for Los Angeles Wildlife), spoke to the Pacific Palisades Garden Club on April 1 about vermin, coyotes and habitat fragmentation.
“Our local mountain lions have a 25 percent chance of becoming extinct because of gene pools,” said Lasken, who noted that the famous lion, P22, that lives in the Griffith Park area “is a very eligible bachelor, but if he’s going to pass on his genes, a female lion will have to cross several freeways.”
Turns out P22 is the only lion in the area bounded on all sides by freeways and someone asked, “Why don’t you just drop a female in?”
“If we drop one in, we haven’t fixed the fragmentation,” Lasken explained, and if the pair have cubs, they still don’t have anyone to mate with—and not enough room to establish new territories.
“It’s important to protect animals by protecting habitats,” Lasken continued, pointing out that CLAW had just saved 17 acres from development in Laurel Canyon, which will allow wild animals to continue to move to different areas. “CLAW has filed an appeal in Nichols Canyon, because it wasn’t given an adequate environmental review.”
He explained that unless some corridors are maintained, a choke point happens, and animals cannot move freely to mate and keep the gene pool healthy.
P22 has on a collar because at one point he was discovered with a bad case of mange that scientists had to treat. Tests revealed that the underlying cause was a weakened immune system because of compounds from two different rat poisons. The lion was treated with topical medications and vitamin K injections and was released.
“Scientists have determined that 83 percent of coyotes that they’ve tested have some sort of rat poison in their system, 92 percent of bobcats have poison and 94 percent of mountain lions have poison in their system,” Lasken said.
He explained how rodicides make the way up the food chain. When a rat or mouse consumes the poison, it can take up to 10 days to kill it. During that time, it may be eaten by a larger predator (or even a cat or dog, which is deadly).
What does CLAW recommend instead of a poison? “Stop the problem before it starts,” Lasken said. “Make sure that your home is sealed from rats and don’t leave pet food outside.”
He said that all fruit under trees should be picked up and that there should be no open dumpsters or garbage cans.
“Trim trees back three feet from the roof,” Lasken said and remember that “rats like to hang out in the ivy.” He recommended using non-toxic measures, such as traps.
Then he suggested an idea for Pacific Palisades homeowners, who live in an urban/wildlife interface area. “Use an eco-system service: Get a barn owl. Their diet exists almost entirely of rodents.” The owl’s range is about a mile and barn owl boxes can be hosted in a yard. The cost is about $200 through clawonline.org.
One warning: If you have a barn owl move into your neighborhood, all neighbors will need to stop using rodenticides.
“These boxes have been used all over the world,” said Lasken, who noted that the barn owl weighs only about a pound. Some sources say that owl boxes can be less costly than rodenticides.
Last year, the Santa Monica Mountains National Recreation Area and the Santa Monica Mountains Fund launched a campaign called #BreakThePoisonChain to educate people about the potential negative impacts rat poison has on wildlife.
Assemblymember Richard Bloom has introduced AB 1788 to amend a current law. The bill would create the California Ecosystems Protection Act of 2019 and expand the prohibition against the use of a pesticide containing specified anticoagulants in wildlife habitats to the entire state.
Lasken then addressed “urban” coyotes. “They don’t mix well with pets,” he observed. “There appear to be more coyotes because development has encroached on their habitat.” And with more development there is more food, including pets and feral cats.
He said that killing coyotes doesn’t work, because in each group there is an alpha male and female. Once one is killed, more coyotes move in because the alpha coyote is not there to chase out the interlopers.
“We can co-exist with coyotes,” said Lasken, who recommended five steps to keep them out of your yard: 1) do not feed coyotes; 2) do not leave pet food outside; 3) do not leave water outside; 4) keep garbage cans closed; and 5) clean up fruit.
He suggested that if you want to let your cat outside, you should make a “catio,” which is a fenced-in patio for the animal.
When you walk a pet, vary the time and route, and if you see a coyote pick up your [small] dog.
He also suggested hazing coyote techniques.
“Some coyotes have lost the fear of people,” Lasken said. “If you see a coyote, don’t run. Make yourself as big as possible. Shout. Throw rocks, stones and do it until the coyote retreats.”
If you stop it before the coyote retreats, these animals are smart and learn there’s no fear. “Have your neighbors do it, too.”
(Editor’s note: When Potrero Canyon Park opens, maybe that could be an area to host several barn owls? Or above the Asilomar and El Medio bluffs? Or in the Highlands? Also, could this area be the first area in the country to give up rat and mouse poison in favor of a smart environmental choice?)