Rodent Census Finds Population Boom : Del Mar--Where Surf Meets the Rats

If Del Mar is truly the elitist community that its envious North County neighbors say it is, no one told the varmints that have established residence here from Sandy Lane to Torrey Pines Terrace.

Del Mar’s rat population underwent an official census recently by county vector control manager Moise Mizrahi. Based on a 27-block survey, the verdict is that 22% of Del Mar’s households have rats. When absent or uncooperative householders are factored in, the figure is more realistically set by Mizrahi as high as 41%.

The bottom line on the city-ordered study is a recommendation for a $40,000 eradication and education program, followed by $30,000 annual follow-ups.

None of the inspectors who poked around in the ice plant and eaves of 437 Del Mar “premises” confronted a roof rat ( Rattus rattus ), but the evidence was overwhelming. Uptown, downtown, on the beach and up the hill, roof rats reside, usually hanging out in dense vegetation that residents call landscaping, or in improperly stacked woodpiles, thorny tangles of bougainvillea, under the house, on it or even in it. Experts disagree on why the common variety of rat is called a roof rat, but all agree that the patter of little feet on the roof is more likely to be a rat than a reindeer.

Droppings, rat-size nests and branch cuttings peculiar to roof rats were all the evidence Mizrahi needed for the announcement that “the rat problem in the City of Del Mar is heavy and must be dealt with.”

In a finger-shaking report, Mizrahi noted that 56%, or 246 of the 437 Del Mar properties inspected, had “rat harborages”--the makings of a cozy abode for the rodents. Twenty-two percent, or 98 of the 437 homes, also had one or more food sources such as fruit trees, dog food dishes and unlidded garbage cans on the property. And 21 of the 67 sewer manhole covers inspected (33%) showed evidence of roof rat activity, he reported.

Mizrahi’s concurrent ground squirrel census zeroed in on the city’s Seagrove Park, where the critters are making mincemeat out of the ocean bluffs. He described the squirrel burrowing activity as “damaging the integrity of the western slopes.” On a scale of one to 10, Mizrahi rated the squirrel infestation in the park as a 6--”somewhat higher than moderate”--and blamed park visitors for the problem.

“Staff noted visitors at the park feed the squirrels, thereby fostering their presence in that area,” Mizrahi stated. The recommended remedy is a “depredation program” (poison placed in burrows) for the squirrels and a sign program for the humans, asking them not to feed the squirrels.

Also reported on the county rodent census report were:

- A light to moderate infestation of gophers in Seagrove.

- A number of house mouse sightings.

- An infestation of American and Oriental cockroaches around manhole covers.

Del Mar is not alone in its rodent problems, Mizrahi said. Coronado and San Diego city officials contract with the county vector control division to eradicate similar varmint invasions. Encinitas and Solana Beach homeowners have long fought the ground squirrel vs. bluff battle. Mizrahi said the county handles the extermination work for Del Mar. For a price, of course.

City Manager Bob Nelson said that the decision is up to the Del Mar City Council because it is difficult to come up with $40,000 in the middle of the budget year.

“They (council members) will have to decide the priorities and whether or not they want to drop some other program costing $40,000” in order to oust the roof rats, Nelson said.

Mizrahi said that there is no need to press the panic button in Del Mar. The roof rats appear to have been established in the community for some time, he said, and “do not present an immediate threat to public health.”

He outlined a program of education and eradication, and estimated that 1,400 man-hours would be required to coordinate the first-year effort. Among his proposals are:

- Responding to citizen complaints and requests for service.

- Coordinating citizen efforts.

- Providing rat poison and instructions to residents who want to do it themselves.

- Placing baited traps at rat feeding and breeding areas.

- Enforcement of tate rat-control laws.

At present, Nelson said, residents haven’t shown much interest in the city’s announcement that the complete rat survey report is available at City Hall. Mizrahi, with years of vector control experience under his belt, can explain the seeming lack of interest.

People aren’t unconcerned about rats, he said. They just don’t want to think about them.