Over 300 Invasive Species Are Taking Over US National Parks

by Jennifer Shea

More than 6,500 foreign species have invaded the U.S., and hundreds of them have made it into America’s national parks.

Collectively, they are wreaking more havoc on the environment, the economy and human health than all the natural disasters put together, according to National Geographic.

Invasive Species On the Rise

“Half the parks have reported problems with invasive species,” Jennifer Sieracki, the Park Service’s invasive animals program coordinator, told National Geographic. “But we suspect the vast majority of parks are affected.”

The parks have a hit list of more than 300 animals to vanquish. Those include rats, quagga mussels, gypsy moths, lionfish and feral hogs, goats and cats.

But the invasive species are obviously also growing beyond the borders of national parks. So the Park Service is trying to cooperate with local agencies and communities to address the problem.

“We need everyone to work together to deal with this issue,” Sieracki said.

That includes the more than 320 million park visitors every year. The Park Service manages about 85 million acres of wilderness, and they’ve got their hands full.

Invaders Causing Extinctions

Guam is one place where an invasive species caused significant damage. Brown snakes showed up on Guam in the 1950s, probably brought there on military equipment. By now there are roughly 15,000 snakes per square mile on the island. 

The snakes often short out electrical systems. And they’ve driven 10 of Guam’s 12 native bird species into extinction. 

Rats often hide away in planes and overtake new habitats, earning them a bit of a reputation. Rats are responsible for between 40 to 60 percent of all known bird and reptile extinctions over the last four centuries, according to National Geographic.

Parks have developed foreign species management programs to kill off invaders, but those can be controversial. For example, cats can prove quite destructive to native bird species, but exterminating them provokes an outcry.

Still, park officials are asking visitors to do what they can to reduce the spread of invasive species. 

They remind people to care for pets that they purchase, and to never just release an animal into the wild. They further ask that people inspect their boots and gear before they hit the park, to make sure they’re not carrying invasive plant seeds that could potentially alter a habitat forever.