Bolson Tortoise Ecosystem Preserve

Our goal is to manage this land with Mexican partners for the long-term protection of the tortoise and the rest of the rich biodiversity habitating there. Land preservation is a priority of the Turtle Conservancy, and this particular property was chosen because of its size, geography, and ecological importance.

The TC team also contributes to research by adapting survey protocols developed for the Mojave Desert Tortoise. The team systematically walks one square kilometer of tortoise habitat in transects, with six to eight surveyors walking side-by-side 10 meters (33 feet) apart, for a total of 100 kilometers. Each surveyor carefully looks for burrows and other tortoise signs in the five meters on either side, and any tortoise signs are recorded and mapped. Where previously only eight burrows were known, this method effectively documented a total of 28 active and abandoned burrows.

We also use drones to fly over a preprogrammed series of transects and take partly overlapping high-resolution photographs, creating a highly detailed photographic map of the area. Such analysis can theoretically be used to identify tortoise burrows, as well as to determine vegetation patterns. Turtle Conservancy scientists are working to develop software technology to scan the images and recognize tortoise burrows by feeding the locations of burrows found by the walking survey team into the drone data. If the drone data can successfully identify most tortoise burrows in the sample plot, then we could use that technology to survey the remainder of the area and estimate total tortoise numbers.

Other activities by the research team involved using a burrow scope—a camera with lights at the end of a long hose—to verify whether tortoises actually inhabit a burrow, or whether it’s abandoned. Most scoped burrows indeed provided clear views of a resident tortoise, often 10 feet down a tunnel or further.