When we purchased our modest-sized, suburban property in Columbia, Missouri, 26 years ago, garter snakes were regularly observed in the yard and flower beds; during some springs, their young seemed to be everywhere. We also noticed a fair number of five-lined skinks (also known as blue-tailed skinks) on the property.
Now, two decades later, the skinks are abundant and the snakes are all but absent. I suspect the garter snakes had preyed on the skinks, keeping their population in check; once their numbers crashed (for reasons unknown....perhaps predation by opossums, raccoons and red-shouldered hawks), the skink population exploded.
Though I am unsure regarding the specifics, it appears that our reptilian imbalance is symbolic of the predator-prey relationships that we observe in all natural ecosystems. As with the gyrations of the cottontail population on our Littleton, Colorado, farm, in relation to the presence or absence of red fox, population dynamics are most evident in contained environments. Since we humans seem committed to carving up what little open space remains, such imbalances will likely lead to an accelerated rate of extinction.
