QUESTION: We live in a condo complex very close to the ocean. Despite a wind-activated "singing string" and a plastic owl, the sea gulls are becoming more and more brazen and fearless as they come for a bath in the pool several times a day. They make a mess both in and out of the pool. Short of enclosing the whole area, do you have any suggestions?
R.B., Redondo Beach.
ANSWER: Keeping sea gulls out of pool areas is one of the easier tasks in the business of controlling pesky wildlife.
Many restaurants around the country, including one on Cannery Row in Monterey and another at Disney World in Florida, have successfully repelled gulls by suspending a simple network of monofilament line or non-rusting wire over the area needing protection.
This tactic also can be applied to your pool area to prevent the gulls from landing.
I talked with Ron Johnson, an extension wildlife specialist at the University of Nebraska, where scientists have tested size, color, orientation and spacing of monofilament lines used to repel gulls and other birds from landfills, fish hatcheries, restaurants and other public places.
Although the bulk of studies on lines have involved ring-billed, herring and laughing gulls, Johnson tells me most other gulls should be equally deterred by the lines. It is merely a matter of experimenting with line spacing, height and grid pattern until you determine what works best in your situation.
To create a barrier, string several strands of 40-pound test monofilament line or 32-gauge stainless steel fishing line over the pool area. Attach the lines to whatever's available or install posts if necessary.
Run the lines eight feet apart at whatever height seems appropriate and safe. Make sure that people can easily walk underneath the lines, and they won't interfere with stairs.
If the birds continue to penetrate the lines, add another series perpendicular to the original set so that you have a crisscross grid.
If the gulls still penetrate the line, fill in the existing spaces so that the lines are only 4 feet apart. And so on.
Gulls have been repelled using a grid of lines as low as two feet off the ground and up to 33 feet. Any higher, however, and they may venture through.
Be sure the sides of the grid extend across the entire area you want covered. Workers at a California Department of Fish and Game fish hatchery in northern California found that gulls may discover a way to land off to the side and simply walk under the lines.
This control technique works on a few other species also, including house sparrows, Canada geese and pigeons.
Exactly why the birds are repelled isn't clear. Obviously, the birds can fit through the lines, which seem to work more as a psychological barrier than a physical one.
How easily deterred the many species of gulls in the Southland (including the ring-billed) will be is also influenced by other factors. Is there food or garbage for the birds to feed on at the poolside? Clean it up and put lids on garbage cans.
Is your pool area the birds' prime loafing area between foraging visits to the ocean? If so, they may be more motivated to stay unless there are alternate resting areas.
Watch the gulls and try to understand what they gain by visiting your pool. In understanding what motivates animals, you often learn better how to intercept their bad behavior.
Wash Food to Avoid Diseases From Animals
Q: I read your column recently on raccoons and the diseases that can be transmitted to humans (zoonoses). This alarmed me considerably.
We have a garden in the backyard and have seen two opossums eating peaches from the tree and running through the garden. We have also seen feces in the garden. Do the raccoon roundworm eggs live in opossum feces? Does this mean the garden vegetables are contaminated and unsafe to eat?
A: The raccoon roundworm, Baylisascaris procyonis, is primarily restricted to raccoons, according to Kevin Kazacos, professor of veterinary parasitology at Purdue University and the nation's leading expert on raccoon roundworm.
But you'd be wise to wash your vegetables and fruit thoroughly before eating. It's generally accepted that food from the garden should be washed under running water for at least a minute.
Your concerns about disease transmission from your furry neighbors are justifiable. In fact, the Los Angeles County Department of Health Services just sent out a health advisory at the end of August concerning marine typhus.
Two county residents have contracted the disease, which is transmitted by fleas that live on wild animals, particularly rats, opossums and feral cats.
The advisory says the disease is "characterized by fever, headache, muscle ache and rash and is treatable with antibiotics."
To keep the number of rodents and opossums around the house to a minimum, the department recommends trimming back ivy and ground cover where the animals live, rodent-proofing the house and garage, bringing in pet food dishes at night and keeping pets flea-free.
The subject of wildlife disease can be unsettling. It's a little like reading the Merck manual: The more you read, the more you're sure you have every disease listed. But taking reasonable precautions like fencing the garden and protecting fruit trees with nets and trunk guards will go a long way toward keeping you protected.
For more information on marine typhus and other zoonoses, call the Los Angeles County Office of Veterinary Public Health at (213) 250-8645. Or contact Orange County's Vector Control District at (714) 971-2421. Ask them to send you some of their pamphlets.
Not a Good Idea to Feed Wildlife
Q: I live in the South Bay and we have a squirrel living in our neighborhood. My children love him and I was wondering what to set out as food in the yard for him.
A: Your letter brings up an important issue, one that's growing in importance all the time, across the country.
With a very few exceptions, such as songbirds, feeding wildlife is a bad idea. Although it's tempting to set food out for squirrels, particularly when they sit on their haunches and look up at you with wide, hopeful eyes, it's a mistake, and here's why.
* We can't match wild animals' nutritional needs with our processed foods.
* The animals may lose their fear of people and may become aggressive when they don't get what they want.
* Their "body clocks" become altered as they adjust to eating on our schedule.
* Populations become larger than they otherwise would or should, which may affect the ability of other species to remain in an area and almost certainly creates a problem for neighbors who spend their time devising ways to keep the animals out of their garden and house.
* Food left out for them may attract undesirable animals like rats and mice and increase disease transmission.
* It often leads to their demise. The recent case of the mother bear in Yosemite and her two cubs is a perfect example. The bears had grown increasingly reliant on food in tents and cars.
When the park biologists felt the bears had grown too dangerous and all reasonable efforts to remove them had been exhausted, the biologists had to kill the bears to keep visitors safe.
This plays out every day in less dramatic terms. People at one house feed marshmallows to raccoons, while their neighbors are frustrated with the animals denning under the porch and damaging their property.
You'd be doing your kids and wildlife a world of good to teach them that if they love wild animals, they'll let them find their own food.
Critter conflicts? Send your queries to wildlife biologist Andrea Kitay at P.O. Box 2489, Camarillo, CA 93011, or via e-mail at email@example.com. Please include your name, where you live and as much detail as possible. Questions cannot be answered individually.