In my very first post, I wrote about experimenting with quahog shell jewelry and witnessing the demolition of their shells by hungry gulls. Since then, as the waters have warmed and the skies became sunnier, we have been treated with an explosion in spineless diversity.
 |
| An enormous knobbed whelk with my hand for comparison. Personal photo |
The technical definition of an invertebrate is an animal that lacks a spinal cord and an internal skeletal structure. Their body structures can be variable, their colors vibrant, and their appetites voracious. The three species I've seen most recently across the island are the knobbed whelk (Busycon carica), eastern carpenter bee (Xylocopa virginica), and inchworms (Geometridae).
The photo above shows giant knobbed whelk that one of my students spotted and caught in Bogue Sound last week. Whelks are easily mistaken for conchs as they are both large marine snails living in spiraled shells with flared openings, and pointed ends. They are dramatic and noticeable animals and my students were amazed that such giant snails inhabit our southern coastline.
 |
| A smaller, but equally impressive knobbed whelk. Personal photo. |
Whelks are the bane of oystermen up and down the Eastern Seaboard since they are a predatory snail that dines on bivalves such as clams, oysters, and mussels. They eat their prey by holding them down with their muscular foot and inserting the lip of their shell between the valves (shell halves) of their victims. After chipping away at their protective shell, they force their way inside and begin feeding on the flesh within. Who knew such violence was habitual in our estuaries day in and day out?
Until a rainstorm passed through late last night the whelks seemed almost guaranteed to stay on for another week. What reason could that be? Well, as it turns out, it's all about salinity.
Salinity refers to the amount of salt present in our water. Freshwater contains no salt and therefore has 0 ppt (parts per thousand), while saltwater is 30-50 ppt. The parts per thousand is a ratio of a certain number of salt molecules (NaCl) to one thousand water molecules (H2O). The sound as of late last week had a salinity reading of 35 parts per thousand meaning that it was effectively salt water and not the brackish water that benefits oysters. While consistent brackish water (0.5-30.0 ppt) reduces the number of whelks slowly working their way into the sound, it won't guarantee that they will depart. After all, when there is a feast to be had, why would you leave?
Meanwhile on land, another feast is happening. As new leafy growth appears on trees all over the island, the annoying strands of inchworms have begun to descend from the trees. Nothing aggravates the skin more than the brush of a silk thread on a mosquito bite. And then another. And another. I've decided that it's annoying enough that it's on par with walking into morning spider webs while hiking on a trail. Yes, it's gotten that bad!
But why are they doing it?
 |
| A black-throated green warbler chows down on an inchworm in Oak Harbor, Ohio. Personal photo. |
Well it turns out they have a darn good reason for doing so. You see, caterpillars like inchworms are favorite foods of many songbirds such as warblers, vireos, chickadees, and wrens. They are small, easy to catch, and plentiful when new leaves begin to emerge in the spring. To combat these predators, the first line of defense is to hide in plain sight. Their camouflage is suitable enough to suggest a broken twig or fruit stem and they will remain still until the predator has left. However, if the disturbance is significant enough to them, the inchworms repel in response.
They won't repel them with harsh chemicals or a dazzling threat display, mind you. They will literally repel down from the tree tops on silk threads. If there are others in the vicinity, they will repel as well. So if you're ever walking down a trail and walk into one dangling inchworm, first look forward to see if there are any more (so you can avoid them sticking to you) and then look up to see what bird has dislodged them from their leafy perch.
 |
| A geometer moth hides in plain sight. Personal photo. |
If they are lucky enough to survive into adulthood, these little caterpillars will become unassuming moths called "geometers", so named because their inching behavior suggests that they are literally measuring the earth beneath their feet. Meanwhile, closer to the nearby trunks of pine and cedars, treads a curious bee with a taste for wood.
When we look up anything about bees, we are bombarded with two intertwining messages: We need to save the honey bees and planting a garden will help them. While honey bees are important commercial pollinators for humans; for the rest of the continent, they are nonnative pollinators that steal the spotlight away from the equally important native ones. If anything, the message should be save the pollinators, not just the honey bees!
 |
| As good as a drill bit and as smooth as sandpaper. Personal photo. |
 |
| Entry hole in cedar pole. Personal photo. |
After drilling up to a foot or more into the wood, the female sections off parts of the tunnel with pollen and nectar for her eggs. She places one in each chamber which grow up with a supply of food before they leave to create their own nest or to overwinter for the next spring season.
As I encountered more and more of these holes, I thought about how valuable this dead wood was for them. While I thought to create something of value with the wood itself, I had to admit that the carpenter bee already had done so by turning it into a home. The wood is valuable in and of itself, without being turned into another form. Before returning with my new wood supply, I checked each log for signs of holes. A few pieces would turn out to have them but fortunately no signs of life emerged after cutting them.
As I cut each piece into sections, I thought about how I'd be turning each piece into a representation of a bird; an aspect of nature, embodied in wood. This isn't a weird thing to do as people have been carving effigies of animals in wood, bone, stone, and other materials for thousands of years. A 2012 article on Forbes.com tells of a wooden Canada goose decoy that sold for 1 million dollars and after attending the Core Sound Decoy festival last December, I overheard buyers agreeing to pay several hundred dollars for these likenesses in wood. We're so strange, I thought before feeling something crawling on my leg. I stopped my sawing, took off my goggles, and looked down. On my leg, marching delicately over my hairs was an inchworm, apparently mistaking my hocks for an unusually sparse tree trunk. I gently removed it and continued working. What wonders from the spineless tribe would I experience over the next few days? Only time will tell.
"When birds burp, it must taste like bugs" - Bill Watterson
Comments
Post a Comment