Grant Funded for Rio Grande Cooter Research

By: Laura Nelson

The Rio Grande cooter (Pseudemys gorzugi), a freshwater turtle commonly seen in waters around Lake Amistad, will soon be the subject of research using state-of-the-art technology.

Sul Ross State Univ. Rio Grande College biology professor Dr. Dan Foley and Dr. Michael R. J. Forstner, a biology professor at Texas State Univ., have already been studying the Rio Grande cooter, marking 100s of individuals over the past five years. Now, a grant from Texas Parks and Wildlife will fund transmitters that will be attached to 10-15 adult individuals. The small, lightweight transmitters will not interfere with the turtles’ normal activities and will provide a wealth of information including where and when the turtles are active, their hibernation patterns, and where the females lay eggs. The grant will also open opportunities for RGC undergraduates to learn about and participate in research methodology, data collection and data processing.

According to Foley, this type of research breaks new ground because the technology will allow them to follow the turtles for several years rather than the month or two that more traditional, time-consuming techniques permit. The transmitters will be programmed to link to satellites four times per day in order to save the information gathered. The process relies upon the turtle surfacing at certain times and staying at the surface long enough for the data to transmit, so while not every movement of every turtle can be tracked, the accumulation of the data will convey where and when the turtles are moving, feeding, and laying eggs.

Little is known about Rio Grande cooter population numbers and how far their habitat ranges. They are fairly common around Lake Amistad, San Felipe Creek, and Devils River, but not up and down the Pecos and Rio Grande rivers like they once were. In fact, the turtle may be threatened, in part due to loss of habitat, but also because they are collected for the pet trade and also used to feed the demand in Asian markets for turtle meat.

Foley said a large number of the turtles may be found in the Dolan Falls Nature Preserve and in August, he and Forstner will choose the adult turtles to study from that population. Foley believes 90 percent of the effort in the research will be finding each individual once per month to retrieve the data. The turtles must be within 1.5 miles of the receiver before their location can be pinpointed, and many hours may be spent paddling area waters to find that signal.

The two biologists anticipate adding to the meager amount of information available about this important species found only in our own backyard.