What you hear in nature is not always what you may think it is. Nature is full of marvel and intrigue, and…copycats. Birds especially can be accomplished mimics not only copying other bird calls, but human made sounds as well.
Most of us have heard a Northern Mockingbird sing the songs of other birds, and we are familiar with the fact that they mimic others. But there are many other bird species that also mimic for various reasons, including the catbird and thrasher species, jays, ravens, crows and others. Starlings and mynas are know as some of the best mimics in the world. And, of course, many parrot species can talk it up!
Besides it being comical, what reasons would drive a bird to mimic other calls or sounds? Why bother to spend time learning and performing all those sounds? There are many reasons, and they vary between species.
Impressing a mate is probably the number one reason mimics. Females will always look for healthy males, with the brightest plumage, but if you can sing 200 calls, your chances are better! Since calls are learned, it demonstrates intelligence and survival strengths. Some birds mimic predators such as hawks around their own nest to scare off other lesser predators. Similar would be for birds to mimic Hawks, owls, cats, and dogs to keep others away from a food source. A big repertoire can also demonstrate a bird’s strength and keep others off its territory. Additional calls can also fool others into thinking there is more than one bird present on the territory. Young birds may mimic older birds within their family or flock to be accepted and included. And in some cases birds accidentally mimic and learn some calls just because they come across the unusual sound.
At the nature center, where I worked in the Rio Grande Valley, we had a resident mockingbird that staked out its territory outside the back door. It knew how to make the squeaking sound of the door hinges perfectly. It also did a perfect ambulance siren, and could make the different sounds of the fire engines. Green Jays, especially at Bentsen State Park, would do Gray Hawk calls around the seed feeders and make every other bird scurry for cover while claiming the feeders for themselves.
Some birds actually have the same calls without mimicry. the White-breasted Nuthatcher and Red-winged Blackbirds make a thin pitched call that sounds like the squeaky toy trumpet horn on a kid’s tricycle. And previously unknown, but as we learned while I did a stint of Ivory-billed Woodpecker searching in the Arkansas woods while working with Cornell…Great Blue Herons can do the same call!
Mockingbirds can learn up to 200 or more calls in a lifetime, and thrashers learn a lot more than that! They add more each year, but don’t always retain all the calls, therefore sometimes sounding like a different bird. And this can drive bird watcher crazy trying to figure out if they really heard what they think they heard…or was it just some imitator! Enjoy the marvel of nature!
