Scientists Seek Crowd-Sourced Data To Map Land Damaged By Wild Pigs

Wild pigs cause serious damage to grazing lands and watersheds. UC Cooperative Extension scientists have developed a GIS-based tracking app to assess wild pig damage in order to figure out how to mitigate the creatures' impacts.

John Harper works as a UC Cooperative Extension livestock and natural resources advisor for farmers and ranchers in Mendocino and Lake counties.

Harper says you'll know it if you come across land "disrupted" by wild pigs.

"It looks like you came in with a rototiller and just uprooted everything," he says. "It's like ground squirrel mounds or gopher mounds on steroids because the pigs can go over such a large area."

But roaming wild pigs are no laughing matter for ranchers.

As they root around for truffles and small plant roots to munch on, their sharp tusks tear through plants or "forage" that sheep and cattle like to graze on. In addition to taking away that food source, Harper says they also put soil at risk.

"It sets (the soil) up for invasive species to come in and that removes productive land out of the area," he says. "So you might get something like 'medusahead,' an invasive grass that tends to crowd out other more desirable forage species."

These are some of the reasons UC Cooperative Extension researchers are asking farmers, ranchers and citizen scientists to use a GIS-based mobile app to gather data about where wild pigs are digging up land or wallowing in creekbeds.

Harper says researchers want to get a better handle on the economic cost of wild pigs roaming rangeland, vineyard and orchards. Right now, there are many unknowns.

"We don't know the extent of the acreage or the extent of the damage," Harper explains. "We don't know the (level of) economic loss associated with that damage." 

The data collection is pretty straightforward. People who see land churned up by wild pigs use a smart phone or tablet to take three pictures of the site. Then they upload the images to the GIS-app to map the location. 

This year researchers are using an online survey to collect basic data about wild pig impacts from farmers, ranchers and vintners and those who manage pasture lands and watersheds. 

The next phase will include training more people to use the app.

Long term, Harper and team members plan to analyze a larger set of wild pig data to come up with strategies for mitigating their impact on pasture lands, watersheds and other areas.

According to the USDA there are more than six million feral pigs across 34 states in the U.S. and that number is rapidly expanding.

California's wild pigs have a variety of origins. Harper says many are descended from domestic pigs who were released into the wild by humans or escaped on their own and bred in the wild with game hogs such as the Russian boar hog.