A Simple Food Chain

I have a beautyberry bush (Callicarpa americana) in my yard. I think it is comprised of more than one individual. I think I remember planting more than one. I wish now, as I look as the thick tangle of stems and downward-curving branches, that I had planted them farther apart. I got those plants from the side of a dirt road in Doyline. I was bird-watching, and had ventured down the road which I knew ended at a little open space at the edge of Lake Bistineau named "Tadpole" by the locals. The right fork of the road went to Tadpole; the left fork went to a really big house that was visible from Tadpole. Folks said that house belonged to Coach Roach's brother. Folks also said Mr. Roach didn't like people on his road.

I'd been to Tadpole dozens of times when I lived out there. I never saw anyone come or go on that road. Before this day, I'd always been on foot, and I never felt like walking an unknown distance to see a house that supposedly belonged to a mean hermit. But this day I was riding in a truck, so when we reached the fork and discovered that the path leading to Tadpole was overgrown and impassable, we decided to venture down Mr. Roach's forbidden driveway. The forest edge created by the dirt road made for incredible birding. We crept slowly down the road, stopping every so many yards to listen for something new. We got to the end of the drive to see an electronic gate, and beyond it the biggest house I've ever seen.

Seeing three cars parked up at the house, we figured we'd soon be explaining to someone what we were doing there, so we pulled to the side of the drive and continued pishing, kissing, and broadcasting a recording of a never-ending Screech Owl call in an attempt to illicit mobbing behavior from unsuspecting birds. Another vehicle came down the road and entered the gate. The driver waved to us as he passed. He came back out a few minutes later, and passed us by, waving again. Not long after that we decided we'd counted every bird we could from that location, and began to drive out. Going slowly so as to hear if something new was singing, we spotted some beautyberry sprouts right at the edge of the road. I got out and pulled a few plants up with my hands. I put the roots in a soda bottle with a little water, and went on with my birding adventure.

I planted the beautyberry that evening. I remember the stem of the biggest sprout had snapped and even though I thought it was lost, I tried to mend it with scotch tape. Three years later, I can still find the stem with the scotch tape bandage. The plants are loaded down with berries. The weight of the berries causes the branches to sag, giving the bush a sort of fountain-spray appearance. The mockingbird whom eats there daily finds it difficult to stay on the branch as he forages. He often falls, and catches himself on another branch, falls again, and so on and so forth until he either has had his fill of berries, or tired of the Mr. Bean routine. I don't know which.

I planted those plants specifically because I wanted birds to have berries to eat. I am happy when I see the mockingbird coming to the bush, but I'm also a little happy when he falls down…because I think he ate my Spicebush caterpillars.

I had collected two Spicebush Swallowtail caterpillars and brought them to live on my spicebushes. I observed them daily (and nightly, since I read that's when they eat). I watched them morph from small blobs of bird droppings into green freaks with giant false eyespots. I watched them change from green freaks with giant false eyespots to orange freaks with giant false eyespots - one a day earlier than the other. And then they disappeared - one a day earlier than the other. I had hoped they had gone off to form their chrysalides. But when I saw the mockingbird shopping around my little spicebushes, I feared my little caterpillars had been somebody's dinner.

So I have mixed feelings about my neighbor the mockingbird. And I'm having second thoughts about the beautyberry's role in my 'landscaping plan.'

Warning Colors

I thought I understood well how warning colors function in nature. It makes perfect sense to me that a blue jay – new to the world – would sample a monarch butterfly. And that after vomiting and feeling quite terrible, he would choose not to eat any more of those orange and black-striped critters. I understand that the blue jay’s experience didn’t help the individual monarch whom he ate, but does benefit the monarch’s relatives within the jay’s territory.

It is also easy to see how a bobcat might approach a skunk, have a negative experience, and learn from it. In fact, I can find innumerable examples of how warningly colored animals teach predators a lesson they will not likely forget.

But what about that coral snake? One can’t learn every lesson first-hand. If a coyote tries to eat a coral snake, it may not survive the experience. Who would that be a lesson to? No one. Unless you want to try to convince me that the coyote had an audience, and that the onlooker learned to avoid coral snakes vicariously.

In The Birder’s Bug Book, Waldbauer speculates that it is possible that the coral snake actually mimics some other, less venomous snake. He supposes that the coyote encounters the other red, yellow, and black snake, and is assaulted with some mild venom. By the time he sees a coral snake, he knows to avoid the aposematic colors.

That’s a thought.

But what is that other snake? This snake would have to be nearly every place the coral snake is…from North Carolina to Argentina. There are 52 kinds of snakes in Louisiana. There are 5 venomous snakes besides the coral snake: pygmy rattlesnake, copperhead, cottonmouth, timber rattlesnake, and eastern diamond-backed rattlesnake. None of these contestants could win a coral snake look-alike contest.

So here’s what I think: Snake-eaters don’t learn to avoid red, black, and yellow rings. They are born with the instinct to avoid those colors. Add this behavior to hundreds of others that we already accept as instinctual (from how sea turtles get back to the same beaches where they started their lives to lay their eggs, to how my dog always makes three circles before lying down), and doesn’t it just make sense?



http://links.jstor.org/sici?sici=0003-0031(198004)103%3A2%3C346%3ARONTBT%3E2.0.CO%3B2-I



http://www.amazon.com/Birders-Bug-Book-Gilbert-Waldbauer/dp/0674002067

Host Plants

I found this caterpillar on the Ouachita Trail at Walter B. Jacobs Memorial Nature Park. I was inspecting Paw Paw (Asimina triloba) leaves for Zebra Swallowtail caterpillars.

I have read that Zebra Swallowtail caterpillars eat only leaves of Asimina species. I have read that Paw Paw Sphinx caterpillars eat only Asimina species. I have read that there is this pyralid moth with no common name (Omphalocera munroei) that eats Paw Paw leaves so voraciously that it defoliates the trees in the middle of the summer, stimulating the trees to grow new leaves, providing the last generation of zebra swallowtail caterpillars with an unusually abundant food supply, and thus is responsible for increasing the population of adult Zebra Swallowtail butterflies that fly in the fall.

I discovered a folded Paw Paw leaf, and pried it open to peek inside, curious to see if I had found a Zebra Swallowtail caterpillar, or a Paw Paw Sphinx caterpillar, or the never-seen-by-me O. munroei. I found this. It's a Spicebush Swallowtail caterpillar. As you might guess Spicebush Swallowtail caterpillars eat Spicebush (Lindera benzoin). They are also known to eat Sassafras. Some sources say they will eat Sweet bay, Swamp bay, laurels. Caterpillars in the Field and Garden say the Spicebush Swallowtail caterpillar "lives in folded leaf shelters on the host." ON THE HOST.

That's a Paw Paw leaf I'm holding. So did I just find another host for the Spicebush Swallowtail?

http://creatures.ifas.ufl.edu/bfly/zebra_swallowtail.htm

http://www.amazon.com/Caterpillars-Field-Garden-Butterfly-America/dp/0195149874

http://www.amazon.com/gp/reader/0618254005/ref=sib_dp_pt/105-3765951-6342023#reader-link

[By the way, the Zebra Swallowtail caterpillars seem to stick to the underside of the Paw Paw leaves. I have discovered that curled Paw Paw leaves most often conceal little jumping spiders.]