By Eric Duran
Many common backyard animals found in your garden are actually from another continent. You may have grown up with them as part of your outdoor landscape, but they didn’t originate here in North America. Some creatures have been introduced accidentally in the soil of potted plants, others were introduced purposefully to help with agricultural problems, and some were introduced purely for aesthetic reasons. This month, we take a look at some of those more common aliens, species of animals from afar.
Roly polys are also called pill bugs, sow bugs, and potato bugs. The roly poly in your garden is actually a terrestrial (land-based) crustacean. Crustaceans are the group of animals which includes shrimp, crabs and lobsters. Pill bugs feed on decaying plant matter, as well as on fungi and algae.
Common Pillbugs (Armadillidium vulgare), which are the species we find here in our yards, are actually native to Europe, and were introduced into North America, presumably, through the introduction of garden and food plants to North America from Europe. Pill bugs are renowned for their ability to temporarily remove toxic metals from soil.
The Mediterranean gecko is commonly seen around outdoor lights on the sides of buildings. These nocturnal lizards, though common around the Houston area in the spring and summer, are not actually native to our area. This active little reptile is originally from the Mediterranean region around North Africa, Southern Europe, the Middle East and India. They were introduced into the port of Galveston, possibly in the early 1900s, and were first reported in the U.S. in Key West in 1915. As far as we can tell, they don’t seem to do much harm to native wildlife.
Most of us have grown up our whole lives seeing earthworms in the garden. While we do have native earthworms here in Texas, by far the most commonly encountered earthworm is the Common Earthworm (Lumbricus terrestris), also known as a Nightcrawler. The Common Earthworm is actually an introduction from Europe. It’s not known exactly how it was introduced, but its popularly believed that they were introduced in the soil of imported plants around Colonial times. They have since spread from the Eastern United States out across the continent. Although they are known to be beneficial for soil and plants, in the far North, these introduced worms upset the balance of highly organic soils that did not have earthworms in large numbers before the arrival of these legless invaders. In the South, they are much less disruptive, and our native earthworms and soils are faring much better.
These are only a few of the commonly occurring animals that many of us grew up with, which are actually not originally from North America. There’s the slimy Chinese hammerhead flatworm, the garden centipede, European Starlings, House Sparrows, and Cuban Brown Anoles, just to name a few. If you’d like to find out more, visit us at the Nature Discovery Center on Newcastle in Bellaire, during regular hours (Tues-Fri, 12-530; Sat & Sun 10 – 530), and talk to one of our naturalists.
Duran is the head naturalist at the Nature Discovery Center, 7112 Newcastle Dr., Bellaire, NatureDiscoveryCenter.org