24
YET, EVEN WITH its triumph, the Supercolony empire was not healthy. It was out of balance with nature. Its huge, dense population was too heavy a burden for the habitat to carry. Many kinds of plants and animals within reach of the worker swarms began to decline, and a few disappeared altogether. Among the first to suffer were other kinds of ants. Those that occupied soil nests similar to that of Supercolony were driven away, or killed and eaten. Those that depended on similar kinds of food found their supplies declining. Their scouts and harvesters were beaten to new food sites by the ubiquitous Supercolony workers. Spiders and ground beetles that once ranked among the chief predators of the Nokobee anthill species were now themselves hunted down as prey.
Supercolony workers were driven by the need for ever more food to supply the unrestrained egg production of the queenlets and the nurseries of hungry grublike larvae located throughout the giant nest. They penetrated parts of the surrounding environment once shunned as dangerous and unproductive by others of their species. They hunted along the waterline, a habitat dangerous for ants. They climbed the trunks of the trees and combed the lower branches, cleaning out caterpillars, sawfly larvae, tree crickets, and any other living thing that could be caught and killed. They captured or unintentionally frightened away pollinators of flowering plants, including the diversity of butterflies, moths, bees, wasps, hoverflies, and flower beetles that once swarmed over the area.
A small number of species were able to stand up to the onslaught of the new myrmidons. Among them were the most heavily armored of the beetles, centipedes, and millipedes. Also relatively safe were mites, springtails, and other arthropods too small to serve as prey. Earthworms were both elusive and shielded by their thick mucus. These survivors were the equivalent of the house sparrows, rock pigeons, and rats that thrive around humans, each either unpalatable or hard to catch.
A very few creatures did love Supercolony and were loved in return. These were the scale insects, aphids, and mealybugs, delicate and sluggish little insects that pierce plants with hollow beaks and suck out the sap. They were protected by the ants in the same manner and for the same reasons that humans cultivate domestic animals. Supercolony nurtured herds of the sap-suckers throughout its domain. The protection the ants provided against sap-sucker enemies, such as ichneumonid wasps that laid eggs in the bodies of the sap-suckers, and ladybird beetles able to kill and eat the little insects outright, allowed the herds to grow abnormally large. The sap-suckers stunted the growth of the infested plants, causing their leaves to turn yellow and drop off.
Unfettered through the absence of all but a few competitors, freed from most ant-eating predators, Supercolony increased not only in total population but also in density. It came to pass that there were simply more ants per square foot than could be supported by the Lake Nokobee shore. What was once a scattering of nests separated by open space was now a nearly continuous ant city. The problem of meeting Supercolony's ravenous needs was basically the same as supporting an overpopulated human city.
By late summer, the growth of Supercolony had already begun to falter. The ecosystem as a whole, their life support system, was suffering. Many of the surviving plants were too weak to set seed. Ground-foraging animals, including brown thrashers, flickers, squirrels, rabbits, voles, lizards, and snakes, avoided the area. They were repelled as much by the scarcity of food as by the bites and stings they were forced to endure when they tried to forage among the aggressive ants.
Supercolony also had become a subject of talk among humans. Picnickers and fishermen who visited Dead Owl Cove steered around the heaped-up soil of its hundreds of nests. The original formicid inhabitants, including the now-vanished Trailheader and Streamsider Colonies, had been scarcely noticed in previous years. Only a few people, usually children, paused to look at the conspicuous but scattered mound nests. Now everyone paid attention to the amazing Supercolony. "It is," they agreed, "a new kind of ant out there, worse than fire ants." Some added, "What's needed is purely and simply an exterminator."
Supercolony had mastered the environment, subdued its rivals and enemies, increased its space, drawn down new sources of energy, and raised the production of ant flesh to record levels.
The truth, nonetheless, was that Supercolony did not have permanent control of Dead Owl Cove. In the long train of ecological time it was guaranteed only a few seasons of success. By trading sustainability of the home for wider dominance, its genes had made a terrible mistake. A price had to be paid, first by the ecosystem and then, with its support systems declining, by Supercolony itself. Life for Supercolony was at its maximum that summer, in the season of maximum growth, but the quality of its life was falling. It owed to nature a debt of energy and materials incurred by overconsumption, the payment of which might be postponed for a little while, especially if Supercolony could conquer more territory--but then it must conquer still more, and yet more, to maintain what it had. The debt could also be postponed if its workers discovered new sources of food on the occupied territory. Yet even that unlikely event would merely increase the density of the population, and the debt would only be increased, not retired.
There should be nothing surprising about the looming crisis of Supercolony. Every species walks a tightrope through ecological time. Launched upon it, there is only one way to keep going, and a thousand ways to fall off. That is the way evolution works, and that is how the natural world as a whole runs itself. The instincts driving the anthill are those that succeeded in the past. The genes that programmed them were selected by particular events in the past. Neither the instincts nor the genes, however, had any way to plan for the future. A major change in the immediate environment, or a mutation of the kind that occurred in Supercolony, could quickly lead to disaster. For a species to continue on in a particular environment indefinitely required precision and luck.
Supercolony had fallen off the tightrope. In this vital way it resembled the great human anthill above and around it. When its end came, it would be at the hands of the moving-tree gods.