Native, Invasive, and Introduced: Understanding the Different Types of Non-Native Birds in America
By Nick Lund
Humans have really made a mess of things. For millions of years, wildlife all over the world was doing just fine just evolving in their own little areas at their own paces. Then here come the humans, all fancy with our big brains and our technology and we start yanking species out of their own little areas and dragging them all over the globe with us. Both intentionally and accidentally, humans plopped all manner of living things – birds, insects, plants, mammals – into parts of the globe they’d never lived and would never have gotten to on their own, and just let the chaos unfold.
Some of those species couldn’t survive in their new surroundings. Others survived. Some thrived, taking advantage of better conditions or a lack of competition in their new home. It was an opportunity these transplanted species didn’t ask for, but dealt with the best they could. Then we had the nerve to call them “invasive.”
We humans are still causing all kinds of messes in the world, but recognizing and understanding our impacts is the first step towards cleaning things up. Nations around the globe have prioritized the protection of biodiversity: the incredible variety of evolved life. In many cases, one of the biggest threats to the biodiversity of an area are the plants and animals that humans have brought there from other places.
Is it fair to demonize “invasive” species? No, they’re only there because we brought them there and they’re only just trying to survive. But if we’re trying to protect biodiversity and trying not to let species go extinct, there are important designations scientists use to describe the relative statuses of different species. Here’s a brief breakdown:
Native
A native species is one that naturally occurs in a particular area or ecosystem, without the aid of human activity. These are birds that evolved in North America, and there are hundreds of native species here.
Endemic
A subcategory of a native species is an endemic one, which naturalists use to describe a species with a range limited to a particular, usually small, area. The Florida Scrub-Jay is endemic to Florida, for example, or the Yellow-billed Magpie is endemic to California’s Central Valley.
Introduced
Introduced species, on the other hand, are ones that were brought to their present location by people. Sometimes birds were brought intentionally, like European Starlings or Rock Pigeons. Other species were accidental imports, like Eurasian Collared-Doves, which escaped into North America after a pet store in the Bahamas was burglarized. (True story!) Either way, introduced species have managed to survive and sometimes thrive in their new home.
Exotic
These are introduced species that aren’t part of stable populations, such as a pet parrot that’s escaped its cage, or Flaco, the Central Park Eurasian Eagle-Owl. Birders can’t “count” escaped pets on their life lists because they aren’t really wild birds, but if a population of exotic birds survives long enough in the wild, it could become “established”.
Established
Established species are introduced species that have created a stable and lasting population in their new home. According to the American Birding Association, which sets rules for what birds can be counted on official American life lists, populations of exotic birds need to meet a number of criteria before they are established, including surviving without human support for at least 15 years. There are dozens of established introduced species in America, including White-winged Parakeet in Miami and the Eurasian Tree Sparrow in the St. Louis area.
Invasive
If biologists believe that an introduced species causes harm to its new environment, they may call it “invasive.” The House Sparrow, native to Europe, aggressively outcompetes native species like Eastern Bluebirds or Tree Swallows for nest boxes. European Starlings also take over nest cavities, and are blamed for millions of dollars in crop losses.
“Invasive” is a loaded term, of course, and can oversimplify the situation into “bad” and “good” species. Invasive species are just doing their best to survive, and may provide positive ecological services in addition to their harmful ones. Still, controlling invasive species is crucial to protecting the diversity of species that makes life on earth so fascinating.
Domesticated
Domesticated species are those that have been selectively bred over many generations to live alongside humans. They’re all descendants of wild species: the domestic chicken was once a Red Junglefowl in Asia, and most domestic ducks come from Mallards or Muscovy Ducks. Though they aren’t given much thought by birders, domestic birds are the most numerous on earth, including a whopping 33 billion chickens.
Does that all make sense? Birders view certain species differently based on their origins and histories, and our own perspectives inform which species we value. Though introduced and invasive species are sometimes disparaged, it’s important to remember that these birds did nothing wrong. They’re just living the lives that were given to them and trying to survive. If you’re looking to get upset, get upset at humans and the messes we’ve made, and then donate to or volunteer with a group working to protect the environment.