Tortoise Fencing

Threatened Mojave Desert Tortoises (Gopherus agassizii) and other Gopherus species face numerous threats, not least from collisions with vehicles as they attempt to cross highways traversing their territories and entrapment in trenches, pipework, and machinery on construction sites. Also, with the increase in solar power installations in desert habitats that are used by the tortoises, fencing is required to keep the animals out. An additional problem is that although exclusion fencing can successfully keep tortoises off construction sites and roads, some individuals have difficulties adjusting to new barriers and their body temperature rises – sometimes fatally – as they pace up and down the fencing in hot weather.

Fencing, along with other mitigation measures, such as underpasses, has been shown to reduce mortality without disrupting the animals’ life cycle too much, but it has to be the right kind of fencing, installed with consideration for the animals’ direction of movement. Otherwise, tortoises may be able to get through or over it – or they may perish trying to find a way through.

Evidence provided by biologists and contractors in Nevada revealed that previously specified mesh fencing designed to exclude Mohave Desert Tortoises had been found to corrode within a few years of installation and posed risks to a variety of animals. Additionally, installation methods often damaged large areas of surrounding habitat.

Fencing can also be used to aid population assessment before the development of new construction sites.