Colorado is home to a wide range of wildlife, including iconic animals such as the mountain lion, the black bear, and the rattlesnake. However, all of the animals found in the Centennial State aren’t actually native. Here’s a look at a few species that most people assume were always a part of the local ecosystem, while actually, they’re not.
1. Mountain Goats
Though mountain goats thrive in Colorado’s rugged alpine terrain, they’ve only been here since 1947. About 5 dozen goats were introduced as game animals to several locations in Colorado including Mt. Evans. Their numbers are now in the thousands. Today, it’s not uncommon to see these white, fluffy alpinists atop technical Colorado peaks. Many conflate the mountain goat with the native Rocky Mountain Bighorn Sheep, and though they both dwell in the alpine zone, they look quite different. Native Rocky Mountain Bighorn Sheep are typically brown with prominent, curling horns compared to mountain goats, which tend to be white with smaller, sharper spikes for horns.
Though moose run rampant across Colorado postcards, they were actually artificially introduced as recently as 1978 by Colorado Parks and Wildlife. Prior to this introduction, transient moose were spotted occasionally in the state, though experts believe populations were never fully established here naturally. While only a few dozen moose were introduced, they thrived and their numbers swelled. Today, there are an estimated 2,500 members of the species spread throughout the state. Don’t be fooled–though they appear docile, they turn aggressive when threatened.
3. Various Trout: Rainbow, Brown, Lake, Brook
Colorado fishers are often more likely to catch one of the non-native trout species found in the Centennial State over the actual state fish – the greenback cutthroat trout. Colorado began stocking nonnative fish species in the late 1800s of trout, including the rainbow, brown, lake, brook varieties. By the 1930s, it was already clear that the native cutthroat was no match to its hardier competitors. Wildlife management hurriedly tried to restock greenbacks in places the species had been pushed out. At the turn of the century, to the dismay of Colorado Fish and Game, new genetic tools revealed that they had stocked a cousin of the greenback cutthroat, but not the endangered fish itself. That could spell ‘trouble’ for the state fish.
4. Northern Pike
This beastly predator has been lurking in Colorado waters since its introduction in the late 19th-century. People love the thrill of fishing for Northern pike thanks to their several rows of teeth and their length – the record length for catch-and-release in the state was nearly five feet. They prey voraciously on other fish species, including several whose populations are dangerously small. Last summer, fisherpeople were actually paid $20 per Northern Pike caught and removed from water around the state.
5. Turtles, Frogs, Starlings
Similar to many other places around the world, Colorado is host to an entire suite of nonnative species small enough to escape attention. For instance, the American Bullfrog isn’t a native species in the Centennial State, but they’re making a home here, preying on the smaller and native leopard frog. Similarly, the red-eared slider turtle, released into the Colorado wild by pet owners, competes with the native painted turtle population. In the aerial space, bird species like the European starling, the pigeon, and the house sparrow compete with local species for the best nesting sites and bagel scraps.