The turtle species that dwell in the world’s rivers, play important, but incompletely understood and largely unappreciated, roles in both the ecology of their respective ecosystems, and in the economy and sociology of the human cultures through which their rivers flow. Accordingly, the precipitous decline of many populations from former levels, and the complete extirpation of some species from large areas of their former ranges is cause for alarm by those concerned, not only with turtles, but with the health and welfare of rivers and humans as well. The causes of these declines are virtually all the result of human activities—including those which involve direct predation on the turtles themselves (and their eggs), removal for the pet trade, and those which result in unfavorable changes in their habitats. The fact that no known modern species has yet been driven to total extinction is testimony to the resiliency and fecundity of river turtle species. This is no cause for complacency—many are almost certainly teetering on the brink now and are facing ever-increasing odds against long-term survival. Some species could be even now beyond hope of recovery, their populations sustained for a time by a relatively few long-lived adults without sufficient collective reproductive “power” to thwart the normal and various mortality sources which plague all turtles, and which their sheer numbers had formerly been able to overcome. However, we are still so ignorant of the population dynamics of these species that we know not which, if any, are doomed. It seems preferable, therefore, as we strive to conserve river turtle stocks that we assume the working philosophy that none is in this category, and focus our efforts and resources toward research and conservation action most likely to return even the most endangered species to robust, sustainable population levels. The roots of the current crisis predate history, beginning with our hominid ancestors, and particularly hunter-gather Homo sapiens’ unparalleled capacity to learn and adapt in order to maximize the harvest of all available food resources.
More Co-parents, Fewer Children: Multiparenting and Sustainable Population
