America's National Parks are being overrun by rats, cats and feral hogsMillions visit US National Parks each year, many hoping to catch glimpses of animals including bison, mountain goats and alligators.
What they don't expect to see are the rats, domesticated cats, feral hogs and many other non-native animals that also thrive there.
The number of invasive animal species in US national parks has put the protected lands under a "deep and immediate threat," says a new study published in the Biological Invasions journal on Monday.
An invasive species is any organism that lives in an ecosystem to which it is not native to and causes harm. Invasive species are among the biggest threats to native wildlife, according to the National Wildlife Federation.
Non-native species may not have any natural predators. This allows them to breed and multiply quickly and then compete with native populations for valuable food and habitat resources, says the NWF. ..............
https://www.cnn.com/travel/article/national-park-invasive-species-scn-trnd/index.html