|"Flat Head Worm"|
I carefully moved the wormy thing to a new, safe location, and covered it with a dish to keep it from being squashed. Then I turned to the computer and Google to figure out what on earth I'd just found. It's always exciting to discover a new animal in your neighborhood! I didn't know where to start, so I just described it. I typed in "flat head worm". Bingo! I could see right away from the images that I'd found my animal. Unfortunately, as I read on, I learned that it wasn't good. I had found a Land Planarian or Flatworm (Bipalium kewense). Almost every article I read said that I should kill it right away because they are invaders from Asia and they dine exclusively on earthworms. I was so disappointed. I really like this fascinating worm. But now that I know what it does, there's no way I can let it outside again. I'm not good at killing, either, so I'm considering keeping it as a pet for a couple of weeks.
|My Pet Planarian, exploring|
So what's the big deal? Who cares if it eats worms? Well, just like the Dung Beetles from my last post, earthworms are extremely important decomposers. They eat rotting vegetation and turn it into rich soil. They crawl through the dirt, aerating and supplementing with their waste, or castings. If we didn't have earthworms, we'd be buried in plant debris. Earthworms are essential, keystone species that many other organisms and systems depend on. But the funny thing about our earthworms is that they are not all native to North America. Those night-crawlers we use for fishing? Not native. One article that I read said that 60 percent of the earthworms in North America are not native, coming from Asia and Europe, brought here in the horticulture trade starting in the 1600's. There is a fascinating article from National Geographic about the Jamestown Colony which talks about the impact of the importation of non-native earthworms and other species. These non-native earthworms are also decomposers, but they are so numerous and voracious that they eat too much plant debris and dig it deeper into the ground. Some plants and trees need more leaf debris for slow leaching of the nutrients and ground cover and cannot extract nutrients from the soil if it is too deep. So the non-native earthworms may be harming and changing our ecosystems in myriad ways. Now that I think about it, maybe it's a good thing if the Flatworm is added to the mix. Maybe the Planarians can keep the non-native earthworms in check, too. Who knows? Anyway, who am I to point fingers and decide which species can stay in Florida? I was born in Utah. Once you start messing with the natural order of things, there is so much moral ambiguity that I get foggy. I think this time I'm going to err on the side of kindness and I'll let my pet Planarian go. I'm not all that keen on killing animals, even rotten ones (like cockroaches) and I've never seen one before, so they are not running roughshod over my yard. Yet. (Famous last words.)