Alligator Snapper Translocation

Alligator snapping turtle (Macrochelys temminckii) conservation has received substantial attention in Oklahoma for over a decade, starting with a state-wide survey of populations in the 1990s, the results of which triggered the inception of a captive propagation and reintroduction program by Tishomingo National Fish Hatchery and Sequoyah National Wildlife Refuge.

This program is ongoing, and release of headstarted turtles began in 2006. Reestablishing populations of turtles by releasing juveniles is, by necessity, a long-term endeavor, in large part because of the long time many species take to reach sexual maturity. Thus, alligator snapper conservation in Oklahoma got a major boost in 2007 by the translocation of more than 250 confiscated adult turtles to the southern part of the state. It is expected that supplementing reintroduction efforts with translocation of these reproductively mature animals will dramatically decrease the time required to generate a stable, self-sufficient population.

As is the case for any major conservation effort, it was important that we measure the long-term results of the release in order to determine its impact. Therefore, monitoring of the repatriated turtles was initiated soon after their release. Radio transmitters, purchased with assistance from the Turtle Survival Alliance and Delta Foundation, were affixed to a subset of the turtles. Dan Moore, a graduate student in Dr. Stanley Fox’s lab at Oklahoma State University, used a combination of radio telemetry and trap-release techniques to keep tabs on the turtles’ seasonal movement and habitat association patterns as they acclimatized to the new environment. Additionally, springtime searches for evidence of nesting have been conducted in each of the last three years, and the results have been used as a proxy for condition of females in the population.

Initially, many of the transmitter-equipped turtles moved significant distances from the point of release. However, within months nearly all of them had settled into home ranges similar in size to those seen in naturally occurring populations elsewhere in the state. Evidence of nesting, in the form of predated nests, was first observed in 2007 within two months following the release. However, the summer of 2007 saw some of the worst flooding in the region in decades and, as a result, we expect that high water claimed any nests that predators failed to uncover. Additional evidence of nesting was observed in 2008 and 2009, including an intact nest that was subsequently covered with a wire cage to prevent predation. In coming years, we plan to use a combination of intensive on-the-ground searching and strategically placed motion-sensitive cameras to identify turtle nests and their potential predators to ensure that some recruitment of hatchlings into the population occurs. This, in combination with continued release of headstarted juveniles elsewhere in the state, will guarantee alligator snappers a bright future in Oklahoma.

- Day Ligon and Daren Riedle

The TSA provided partial support for the reintroduction of alligator snappers in Oklahoma with funds from the 2007 Batchelor Foundation grant.