Moseying: Living La Vida Llanero
Changes in the landscape the ecology of development
November 29, 2006
The landscape at my workplace and at my home has changed. Last summer the homebuilder Lance Friday cleared the mesquite thicket directly south of the Sibley Nature Center for a housing development. Now earthmovers have created a pattern of streets and foundation fill and when the project is complete, over a hundred families will be moving into affordable workforce housing.
When I came home the day before the Thanksgiving holidays, the property just east of my homestead (the Gone Native Arboretum) had been cleared in just one day. Huge piles of brush and dirt dotted the acreage. I have yet to learn what will be done with the property, but I assume it will be housing. Four other substantial homes have either been built, or are being built to the west and southeast of my home.
Both developments are signs of a vibrant economy. Midland has the lowest unemployment in the state. Even before the spike in oil prices Midland had seen a terrific flurry of new construction, and with the $70 a barrel oil prices earlier in the year less than a hundred houses had been available for purchase. Times are very, very good in Midland, Texas.
In places of scenic beauty or of fertile and bountiful farmland, development has at times created an anti-development backlash. Many groups have been formed to preserve the landscape, or a way of life. In Texas, greenspace and wildlife habitat are major issues. In the hill country west of Austin the groups protecting rare birds such as the black-capped vireo and the golden-cheeked warbler have fought long protracted battles with developers. The Rio Grande Valley has less than 15 percent of its original landscape remaining. Many of the citizens of Alpine are upset over La Entrada al Pacifico and heavy truck traffic that will increase exponentially as that major transportation artery is developed in the coming decade.
Here in Midland the only issue that some citizens fret over is that of water. Can Midland sustain itself? Will new developments be built with a goal of water conservation? The issue is not an overwhelming one in the minds of most Midlanders. Less than ten percent of homeowners have adopted drought-resistant landscaping. Less than a tenth of a percent have rainwater collection systems. Home landscapes use 40+% of our water. The City of Midland, by passing a commercial landscape ordinance encouraging drought adapted landscaping, promotes water conservation. There is no groundswell to create such an ordinance for new home landscaping, however.
Our countryside is bleak an overgrazed wasteland of mesquite, cactus and weeds, reported the Audubon magazine over a decade ago. There are miles and miles of similar landscape, and no endangered species are endemic to the southern Llano Estacado (other than the Texas Horned Lizard that is on the Texas Endangered Species list.) There is no drive for preservation of the landscape here in Midland County. It is our shared perception that what we humans put on the landscape is prettier than what exists (except for pipeyards, warehouses, and other industrial development.)
I live and work on two pieces of property that preserve the landscape. How will development affect the ecology of those protected landscapes? What happened over the last six months at the Sibley Nature Center?
During the initial clearing of the property south of the Sibley Nature Center, we saw a brief period of increased roadkill. Rabbits, skunks, and non-venomous snakes were the most evident. For most of the summer and fall packrats and cottonrats increased dramatically. Both species were active even in daylight hours. Some of the landscaping suffered from their hunger. The bark of some of the trees and shrubs were stripped. Every group of visitors on the trail reported seeing at least a dozen cotton-tail rabbits. Despite a year of slightly above average rainfall the native grasses did not fill in between the mesquites, overgrazed by the rodents and rabbits.
After six months the numbers of rodents and rabbits dropped due in part to the presence of one lone hawk that spent the late summer and fall harvesting the bounty. For the first time in a few years a badger hunted among the mesquites, leaving its trademark domed shaped holes. A roadrunner family raised young in one of the live oaks in front of the building, harvesting the young rats. Very little coyote or bobcat sign was found, so the majority of the vanished rodents may have died because of stress-related diseases.
In the 40 acres of the development some birds were displaced. By using known territory size in our calculations, we hypothesize that two families each of cactus wrens, curved-billed thrashers, pyrrhuloxias, mockingbirds, four or five families of lark sparrows, and one covey of scaled quail were displaced. By using our knowledge of population density of reptiles, we also calculate that 6 box turtles lost their homes, if not their lives, along with two each of bullsnakes, hognose snakes, and kingsnakes. Several dozen ground snakes, black-headed snakes, and blind snakes also lost their homes. Fifty southern prairie lizards, ten whiptail lizards, and at least ten horned lizards were killed or displaced.
Among the invertebrate animals the numbers lost were much higher, but few would mourn the passing of 1000 scorpions or 500 tarantulas! No one knows for sure how many invertebrate species populate an acre of West Texas mesquite brushland, but it is definitely above 3000 species. Hundreds of thousands, if not millions, of invertebrates died in the clearing of the land.
Some individual invertebrates survived the initial development by remaining deep underground, and will recolonize the new home landscapes, such as several species of ants, beetles, termites, and mites. Some were able to escape to the Sibley Nature Center, or to the other surrounding human-created habitats (the Ranchland Hills Country Club, the apartments to the west, or the housing district further south.) 99.99% of the surviving invertebrates were unnoticed. The only species influx that the Sibley Nature Center staff noticed was that abnormal numbers of robberflies were present during the week of the clearing.
Millions of individuals of approximately 250 plant species were obliterated, but their seeds remain to be weeds for the new homeowners. Individuals of 100 or so species of fungi, algae, and lichens died, but their spores remain.
The development was a catastrophe for millions of individual living things, but very good for Midland. It is merely the price of progress. In the grand scheme of things nothing happened, other than we humans extended our dominion.