San Francisco is without doubt one of the 'rattiest cities in America.' Will rat contraception assist? – San Francisco Chronicle


Rats have plagued people for hundreds of years. They unfold ailments; contaminate meals; chew by pipes, electrical wires, gasoline traces and constructing supplies — after which there’s the “ick” issue.

Controlling infestations is a problem, particularly in California, the primary state to ban super-toxic rat poisons as a result of additionally they kill hawks, eagles, mountain lions and different species that feed on poisoned rats.

Now there’s a brand new device to battle vermin: rat contraception.

“Name it reproductive administration; contraception makes it sound like tiny condoms or one thing,” mentioned Tamara Barak Aparton, spokesperson for the San Francisco Recreation and Park Division, which deploys the rodent contraceptive ContraPest in metropolis parks as an adjunct to conventional strategies corresponding to snap traps and pumping carbon monoxide into rat burrows.

San Francisco received the doubtful distinction of rating No. 5 on pest-control firm Orkin’s annual listing of the 50 Rattiest Cities in America in 2021, for the second 12 months in a row. Making issues worse, the pandemic exacerbated rat points nationwide. Restaurant closures prompted mass migrations of rats to residential areas.

Zach Goetschi sets up the new rat contraceptive bait at KidsPower Park. San Francisco CA, Thursday, Apr. 14, 2022. The City has chosen a new contraceptive bait that will slow down the growth of its rat population.

Zach Goetschi units up the brand new rat contraceptive bait at KidsPower Park. San Francisco CA, Thursday, Apr. 14, 2022. The Metropolis has chosen a brand new contraceptive bait that can decelerate the expansion of its rat inhabitants.

Felix Uribe / Particular to The Chronicle
Zach Goetschi installs the new contraceptive bait in a rat trap at In Chan Kaajal Park. San Francisco CA, Thursday, Apr. 14, 2022. The City has chosen a new contraceptive bait that will slow down the growth of its rat population.

Zach Goetschi installs the brand new contraceptive bait in a rat lure at In Chan Kaajal Park. San Francisco CA, Thursday, Apr. 14, 2022. The Metropolis has chosen a brand new contraceptive bait that can decelerate the expansion of its rat inhabitants.

Felix Uribe / Particular to The Chronicle

Video at high: A motion-activated digicam captures rats in San Francisco’s Portsmouth Sq. investigating a bait field containing oral contraceptives. Images above: Zach Goetschi units up the brand new contraceptive bait at KidsPower Park, high, and installs it in a rat lure at In Chan Kaajal Park, above. Images by Felix Uribe / Particular to The Chronicle

ContraPest is available in a liquid laden with fats and sugar — basically a rat milkshake — that stops the maturation of feminine rats’ eggs and interrupts the sperm manufacturing of male rats. Ingesting an quantity equal to 10% of a rat’s physique weight (a typical each day liquid consumption) disrupts fertility for about three months, based on SenesTech, the Arizona firm that makes it. Rats must eat it a number of instances to stay infertile all through their common one-year lifespan.

SenesTech mentioned ContraPest shortly breaks down in a rat’s system and poses no hazard to animals larger up the meals chain. Research it carried out to win EPA approval present that the one facet impact for different species is gentle pores and skin irritation.

Rats are astonishingly prolific breeders. One couple and their descendants theoretically can produce as much as 15,000 vermin a 12 months, based on fashions from National Geographic, though predators, drought, chilly, meals shortage and overcrowding cut back that.

“Killing rats is just half the equation,” mentioned Ken Siegel, SenesTech CEO. “The vital issue that drives rodent populations is the start fee. You can’t kill them quick sufficient or sustainably sufficient.”

Most commonly encountered domestic rodents in the Bay Area: Norway rat, roof rat and house mouse

The San Francisco parks division has used ContraPest since 2019, mentioned Zachary Goetschi, a pest-management specialist.

The milkshake is served in two bottles inside the identical sort of rat bait stations used for traps or poison. Barely bigger than a shoebox, a bait station usually has two small holes for rodent entry and is locked to maintain the contents safe from youngsters and pets.

The most important difficulty, Goetschi mentioned, is luring rats to bait containers after they have already got ample meals sources. His technique is to get trash picked up extra usually and to “pre-bait” containers with peanut butter.

However rats do appear to drink ContraPest, he mentioned, and it’s made a distinction.

In Chinatown’s Portsmouth Sq. Park, his crew counted 60 burrows, every of which could home 4 rats. Inside two months that they had it all the way down to 16 utilizing ContraPest alongside standard strategies.

Contraception might be much less labor intensive. With traps, exterminators have to go to usually to eliminate carcasses. With the contraceptive, they’ll “set it and neglect it,” he mentioned, checking again after a month.

“There isn’t any one technique that’s best for rat abatement,” Aparton mentioned. “It’s every thing collectively — eliminating meals waste, vegetation administration, trapping, contraception, and so forth. It’s type of like Whac-a-Mole, to combine my rodent metaphors.”

In the wild, rats have an average life span of 1 year

Loretta Mayer, 72, and her spouse, Cheryl Dyer, 70, who’ve doctorates in biology and pharmacology/physiology, respectively, invented ContraPest by chance.

After a detailed good friend died of a coronary heart assault, they realized there’s a dearth of research of coronary heart illness in post-menopausal ladies as a result of lab rats and mice don’t expertise menopause except their ovaries are eliminated. The couple developed a product known as Mouseopause to induce menopause in mice — then realized its energy for pest management.

“Everybody’s acquired the terrible story of a canine who acquired into the rat poison and died,” mentioned Mayer, who personally tasted each batch within the early days to ensure the chemical compounds’ bitter flavors have been masked.

They based SenesTech in 2003, however left the corporate three years in the past and don’t have any monetary relationship with it.

Mayer and Dyer nonetheless work on contraception for wildlife by their nonprofit FYXX Foundation.

Their high precedence is creating contraception for invasive mice introduced by nineteenth century sailors to the Farallon Islands. This might be a substitute for the controversial plan accepted late final 12 months by the California Coastal Commission to drop 3,000 kilos of poisoned bait from helicopters. The poison drop for the wildlife refuge 27 miles offshore from San Francisco can be carried out in fall 2023 on the earliest.

The mouse contraceptive compound is principally an natural complement, which suggests it will not want years of a authorities approval course of. However it must be strong so it could possibly be delivered by drone drops.

“I’d be the happiest little scientist on the planet” if the complement could possibly be deployed as a substitute of poison, Mayer mentioned. “The mice have been there since 1850; why can’t we look ahead to a brand new know-how?”

Each litter of rats produces 5 to 10 rat pups

A Cooper’s hawk bleeding to dying on a Berkeley sidewalk a decade in the past spurred Lisa Owens Viani to begin Raptors Are The Solution (RATS), a challenge of Earth Island Institute in search of to finish use of rodenticides that additionally kill birds of prey feeding on rats. Across the identical time, her neighbor discovered fledgling Cooper’s hawks useless in a kiddie pool. She had the birds examined at UC Davis and found that they had ingested rat poison, presumably by consuming poisoned rats.

The group acquired California to move AB1788, which bans extremely lethal rodenticides, though they’ll nonetheless be utilized in agriculture, and fewer poisonous ones stay obtainable.

She’s a fan of environmentally pleasant options for rat management, noting that these additionally embody preventative measures owners can take, corresponding to chopping tree branches, sealing openings in a home and eradicating meals sources.

ContraPest “appears promising, positively an vital a part of the device equipment to assist curtail rats,” Owens Viani mentioned.

Her group is engaged on a pilot project in Seattle to check ContraPest at a constructing slated to be razed. Ordinarily, builders deploy poison earlier than a constructing is demolished, she mentioned, as a result of in any other case the rats residing beneath it scurry out. RATS’ challenge is utilizing ContraPest to attempt to rein within the rats prematurely.

“In 27 weeks we’ve seen a 91% lower in rat inhabitants,” she mentioned. “It’s very encouraging.”

Nonetheless, she, like others interviewed, thinks the product’s greatest limitation is that it prices far more than poison or traps. A single tank is about $28, however a giant space corresponding to a business barn would possibly require about $600 a month, Siegel mentioned, an quantity that might decline because the rat inhabitants declined. In contrast, a dozen snap traps value about $20, Goetschi mentioned.

Presently, ContraPest is offered solely to exterminators and business amenities. The corporate is working to get it on ironmongery store cabinets.

One rat averages 3 to 6 litters per year

Whereas the one research of ContraPest’s effectiveness come from the corporate itself, anecdotally, there are tales of it working — in addition to tales of rats turning up their noses on the milkshake.

Luis Agurto is CEO of Pestec, a pest-management firm that’s contracted with San Francisco since 1998 to manage every thing from mosquitoes to rats.

“In idea we like it,” he mentioned of rat contraception. However there’s a giant “nonetheless.”

“We spent a while exploring (ContraPest) in just a few locations and have had a troublesome time getting rats to eat it,” he mentioned. “We tried in 4 totally different locations for months at a time. I do need to give it a good shot, so we have to maintain making an attempt.”

He mentioned he employs strategies corresponding to “pre-baiting” with attractive meals to get rats and can proceed to take action.

One rat averages 3 to 6 litters per year

On the opposite finish of the spectrum, Little Hill Sanctuary mentioned it had spectacular success with ContraPest.

Helbard Alkhassadeh and his spouse, Camilla, look after about 100 rescued animals — goats, sheep, turkeys, chickens, miniature horses and pigs — on the Royal Oaks (Monterey County) sanctuary.

They quickly found rats feasting on their saved animal feed.

“We had created an setting for them that was luxurious — like a five-star lodge with a buffet,” Alkhassadeh mentioned ruefully.

As vegans who needed to apply compassion towards all animals, they felt it will be fallacious to kill one species of animal whereas rescuing others. So that they purchased dwell traps to seize rats and launch them on public land.

“I went into the barn, set a dwell lure, and the following day there have been 12 rats in it,” he mentioned. “The following day I caught 20 rats. In 5 days, I caught 70 rats in only one small constructing. I instructed my spouse, ‘I don’t know if that is going to finish; they’re in all places.’”

He discovered about ContraPest and set out its bait traps about six months in the past within the 4 totally different areas the place the sanctuary shops feed. The fee was about $250 a month initially, he mentioned, however can taper over time.

“Throughout the first six weeks, I seen one thing was totally different,” he mentioned. “You would inform there wasn’t the identical sort of site visitors from the rats in any of the buildings. By the third month, I finished seeing rats, they have been simply gone.”

He thought perhaps they have been hiding, so he put out dwell traps once more. No rats.

“I attempted every thing, no rats, no indicators of rat droppings or chewed wooden,” he mentioned. “We don’t see any rats; they’re gone. It eradicated them.”

In San Francisco, the place Recreation and Park oversees 225 parks protecting about 4,100 acres, 5 full-time staffers work on pest administration, as do exterior distributors.

A few of these “distributors” work without cost.

“Our open areas additionally profit from nature’s rat management — raptors,” Aperton mentioned. “Our bigger parks particularly, corresponding to Golden Gate and McLaren, present loads of habitat for these birds of prey to hunt, breed and nest. Even a number of the smaller parks can permit raptors to thrive.”

15,000 rats are potentially produced in a year by one couple and their descendants

Carolyn Stated is a San Francisco Chronicle workers author. E-mail: [email protected] Twitter: @csaid


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