WHERE ARE THE WEASELS? COUNTY RESPONDS TO QUESTIONS OVER GOPHER POISONS AT LINDO LAKE

Printer-friendly versionPrinter-friendly version Share this

 

By Miriam Raftery

August 18, 2016 (Lakeside) – Weasel-watching has been a popular pastime for photographers at Lindo Lake Park. But after the County applied poison to kill gophers, a reader of ours raised questions over what impact that could have on weasels, which have not been popping up in the area lately.

Weasels were last confirmed in the park in August 2013.  A Reader report indicated that their primary food source was gophers—providing natural predator control.

Gig Conaughton, county spokesman, explains why the gopher treatment plan was adopted.  “Gopher tunnels and holes create a public safety concern by creating an unstable ground surface, erosion concerns and tripping hazards. They also create landscape issues — by destroying and inhibiting the growth of vegetation.” The poison bait was applied underground in active gopher burrows to limit access and only near walkways and paths, where the gophers posed the most risk to the public, he said.

Conaughton said weasel activity at the park has not been confirmed for several years. “Still, we conducted a thorough review of the property, both to check for weasels and to provide for the safe and proper use of the pesticide. Not only did we not find any weasels in our physical survey, we did find lots of gopher holes — another indication that there were no weasels in the area because they eat gophers. We also searched the state’s database and did not find records of rare, threatened, or endangered weasels in the area.”

He added that the product used is zinc phosphide, which breaks down after gophers ingest it. Zinc phosphide is “grain-based and specifically formulated to target rodents.” Weasels, by contrast, are carnivores.

The application of gopher bait in county parks is consistent with regional and state efforts to combat gopher infestations, Conaughton said, adding that strict protocols are followed per state and federal regulations.  “Licensed technicians locate active underground gopher runways using a specially designed gopher probe and apply small amounts of the gopher bait underground into the main runway. The product selection, combined with the application method, makes it unlikely that it can be consumed by predators that eat the gophers,” he concludes.

According to a toxicology resource, “Secondary toxicity to mammalian predators from zinc phosphide is rather low primarily because the compound does not significantly accumulate in the muscles of target species. Some of the toxic effects to predators have been due to the ingestion of zinc phosphide that was in the digestive tract of the target organism (the prey). However, most predators will not eat the digestive tract. Studies on secondary organisms have focused on coyotes, fox, mink, weasels and birds of prey. Under field conditions most of the toxic effects to non-target wildlife are due to misuse or misapplication of this rodenticide."

So what happened to Lindo Lake’s weasels?   Drought and predation may have taken a toll, but no one really knows. As long as the County continues to kill off gophers that are the weasels’ primary food source, however, the prospects of weasel populations returning may be slim.

Below are some videos and photos of Lindo Lake’s weasels taken by several photographers back in2013, for weasel aficionados to enjoy:

Video by photographer Billy Ortiz:

https://www.youtube.com/watch?v=x-kS0c9lg58

Again on 6/28/13:  https://www.youtube.com/watch?v=Aw1Jw-FAMdE

The Reader ran a story on weasel-watching at Lindo Lake on June 5, 2013:  http://www.sandiegoreader.com/news/2013/jun/05/stringers-video-weasel-watch-lakeside-park/

More photos on the Save Lindo Lake Facebook page: https://www.facebook.com/Save-Lindo-Lake-Lakeside-Ca-256308657842825/photos/?tab=album&album_id=257140964426261

Thomas Blackman also documented them with photos in 2013:  http://obeach.smugmug.com/keyword/weasel;san%20diego%20county;lindo%20lake/

Jay Keller posted images taken in August 2013:  https://www.flickr.com/photos/71649753@N07/9507469096


Error message

Support community news in the public interest! As nonprofit news, we rely on donations from the public to fund our reporting -- not special interests. Please donate to sustain East County Magazine's local reporting and/or wildfire alerts at https://www.eastcountymedia.org/donate to help us keep people safe and informed across our region.