Essays

Moseying: Exploring the Natural World

Comparing two communities of organisms 100 yards apart
June 24, 2009

I sat in the shade of trees at the pond, idly watching Gulf Fritillary Butterflies half-heartedly play chase. Flutter, flutter, swoop, turn, then both lit, their wings held out stiffly so all I could see was the top surface, a brilliant glowing orange. One raised its wings - a flash of luminous reflective silver. A few seconds later the other did the same. A black-chinned hummingbird distracted me as it visited a dozen thistle flowers where it caught tiny insects, then to came to investigate me and hovered less than three feet away me. It faced me and scolded me with three fussy chips that preceded its flight to a twig where it seemed to withdraw into itself. For five minutes it did not move. I heard a Bobwhite give an urgent call, a call that split the air, as loud here as its voice would be there, 200 feet away. The butterflies flashed their wings again, one after the other, and resumed their lazy chase.

A frog sat motionless in the water near to my feet. I glanced his way at least a dozen times and he was still in the exact same position. The water snails at his feet weren't, however. When I first noticed them, their formation was similar to the "W" or "M" of Cassiopea, but now they were more in the pattern of the Big Dipper.

I watched a young Bewick's Wren land in the tree above me. He practiced his song a few times as he descended, looking for insect eggs or other food. He'd arrived only a week or two before, in the company of a sibling, but now they didn't stay together. When the wren landed four feet above me he suddenly became aware of my presence and began fussing vociferously - a non-stop stream of invective that lasted ten seconds or so. Satisfied that I'd been chastised, he flitted to the next tree. I could hear young orioles fussing a tree or two farther away, and one of the young Cardinals was chipping in the shade of a thicket in the other direction. A Mockingbird uttered gross squawks from the another tree 40 feet away in the other direction. I looked at the flowers again. Five species of butterflies were visible, as well as two species of flies, one on each of my knees.

Earlier in the morning I also spent time a hundred yards away at a patch of open prairie with only a few small mesquites. No birds visited while I wandered across it, but surely several visited it when I wasn’t there, for I found ample invertebrate food.  I spent time watching grasshoppers and mapping where each species was found. I tried to correlate categories of grasshoppers with plant types, but nothing conclusive was proved.

I came up with two theories. First, a hatch created a grouping - grasshoppers lay eggs in a group. Secondly, maybe groups formed for mating in leks, like prairie chickens. This second theory could certainly apply to the Painted Grasshoppers, for they mated constantly. Possibly the ungrouped grasshoppers were species in which eggs are laid singly -- or perhaps these ungrouped hoppers were not yet sexually active.

What else was out there? Several horny toads, several whiptail lizards, and a box turtle. I found droppings of rabbit, coyote, raccoon and fox. A snake skin lay empty, half of it disappearing into a hole. I found several holes - ground squirrel holes, cotton rat holes, and smaller holes possibly made by a species of mouse. And still smaller holes, made by tarantulas or wolf spiders. Holes the size of a pencil, and there were many, were ground bee homes. I saw many types of arthropods: robber flies, butterflies, spiders, green lacewings, termites, black beetles, flower bugs, moths, a mesquite cicada - 40 species of invertebrates in this one acre of grassland, and there were 51 species of plants present. I also found three types of fungi (including bird-poop fungus). Cryptogamic soil – now dried mats of algae, moss, and fungi - was also present.

Time was another component of community, I realized. None of these invertebrates except the grasshoppers had been present before an inch of rain. Other than the grasshopper population, I did not analyze the interactions of the members of the grassland community. Just one acre of grassland and one small pond can provide a lifetime of study!