Essays

Wild On The Prairie: Habitats

Temporary Pluvial Ecosystems
April 15, 1999

IT RAINED! IT RAINED! IT RAINED! Did you dance with joy? Did you go for a walk to enjoy the freshly-washed landscape? Did you hear the birds sing as the sun shone for a few minutes at the end of the rainy day? Did you see a toad hopping and plopping along?

It was so amazing – the native grasses turned brilliantly green in a single day! Along one stretch of road southeast of Midland, forty species of wildflowers began blooming within a week of the rain, joining the two lonely species that preceded them.

Later in the year, when the soil temperature is 68 degrees or more, an ephemeral rain ecosystem exists for a few days. The basis of such an ecosystem is the presence of grass root termites. When walking on the prairie, one often notices small mud tubes encasing dead plant matter. Sometimes the mud tubes extend as high as eighteen inches along the upright stalk of a dead plant.

Many insects, arthropods, and birds eat the alates (the winged males and females) when they emerge to mate in the air. Following a thundershower hundreds of thousands of alates per acre fill the sky near sundown. Nighthawks, scissortail flycatchers and kingbirds go berserk at the bounty, sweeping and swooping with mouths wide open, beaks clacking at every gulp. Tarantulas open their burrows and lurk at the rim of the hole for passing victims. Male tarantulas roam about, hoping to find a female with her door open.

In May and June, giant red mites (known locally as rainbugs) emerge from their burrows, the morning after a rain to feast on the dying male termites that litter the ground. Midland County has approximately thirty species of ants that also swarm the morning after a rain. The flycatchers go “nuts” again, feasting during the two to three hour madness.

Millipedes also come forth after a rain, looking for rain- softened decaying vegetation, their favorite gastronomical delight. Several species of beetles have similar tastes, joining the millipedes at choice locations.

Because many species of arthropods nest underground, after a rain a dozen holes per square foot can be found. Some belong to various species of ground bees. Others belong to beetles, thread-waisted wasps, and several species of wolf spiders. Each type of critter moves dirt in a different way – piling it, spreading it out, or pushing it in one direction.

Fossorial mammals also move the rain-softened soil. Pocket gophers sometimes dig lengthy new tunnels in one night, piling the dirt aboveground at intervals. Ground squirrels open new back doors and dig new hidey-holes within their territories. Mice of several species, cotton rats, and kangaroo rats get busy as well.

After a rain on the arid Llano Estacado, a curious observer can spend hours walking about and wondering which creature has done what, and if lucky, can see one at work. But… after a week without rain the activity dwindles. If sufficient rain has fallen, insect herbivores and pollinators (and their predators) become the most visible signs of animal life.

Native plants of the Llano respond rampantly to rain. Because the moisture will soon evaporate, some plants, such as cactus, store water. Others use the brief shot of rainwater for quick flowering and seed production. Some annual plants need a scant two inches of moisture to complete life spans of only six weeks. Other plants grow at phenomenal rates after a rain – Careless Weed can grow a foot in a week.

Our native plants reflect the limitations of the local environment, surviving long dry spells, such as the present eight year drought (and, sadly, two rains in ten days does NOT end a drought). We spend a great deal of money on the beautification of our yards and, in many cases, unrealistically attempt to recreate landscapes of other places.

The current drought is not severely affecting the average homeowner chiefly due to the foresight of creating Lake Ivie (which was built to slow the usage of our precious underground water. Water conservation measures will become more of a political issue if the drought continues.