Biologists in slow race to help North America’s rarest tortoise

Biologists in slow race to help North America’s rarest tortoise

Biologists in slow race to help North America’s rarest tortoise


Less than 2,500 tortoises are believed to remain in the wild in Mexico, and experts warn that dangers to the species are growing due to pet and food hunting.

Bolson Tortoise:

With a carapace (shell) length of roughly 46 cm (18 inches), the Bolson tortoise is the largest of the six North American tortoise species. It is also referred to as the Mexican gigantic tortoise or the yellow-margined turtle.


This species is indigenous to the Bolsón de Mapim, a section of the Chihuahuan Desert in north-central Mexico.

Discovery: Only in 1959 was the Bolson tortoise discovered. It is reported that the discovery of this species was made possible by biologists who were working in the Bolsón de Mapim and saw hens consuming food from a sizable tortoise shell.

Conservation Efforts:

The Bolson tortoise and the distinctive flora and wildlife of the Bolsón de Mapim were protected by the establishment of the 340,000-hectare Mapimi Biosphere Reserve in 1979. Nevertheless, despite this designation, mining and livestock grazing continue inside the reserve, and it is unclear how this will affect the tortoise.

Population decline: 

Based on data gathered in 1983, research from 1991 predicted that less than 10,000 Bolson tortoises were still present in the wild. The overharvesting for food and the pet trade, as well as habitat encroachment from roads, trains, and farmland, are mostly blamed for the population drop.

Local conservation initiatives: 

In some regions of the tortoise’s range, local populations are aware of the species’ protection and actively participate in its preservation.


 There are issues with the tortoise’s continuous collecting for consumption in the northeastern portion of its range, close to La Sierra Mojada. The Mapimi Biosphere Reserve has also seen significant land removal for agriculture, notably maize growing, and cattle grazing.

IUCN Classification:

 Due to persistent risks and population reduction, the IUCN Tortoise and Freshwater Turtle Specialist Group recommended downgrading Gopherus flavomarginatus from Vulnerable (VU) to Critically Endangered (CR) in 2018.

How is the species being protected from being extinct?

  • Reserves that are Protected: The Mapimi Biosphere Reserve was established in 1979, which is a crucial step in preserving the Bolson tortoise and its natural habitat. The purpose of this expansive reserve is to offer a home for the tortoise and other rare plants and animals in the Bolsón de Mapim area.
  • Legislation and Regulations: The Bolson tortoise is legally protected by both domestic and foreign legislation, including the Endangered Species Act in the United States. Without the right authorization, it is prohibited by these laws to injure, gather, or trade these tortoises.
  • Education and Awareness: Governmental organizations and conservation groups aim to increase public understanding of the endangered status of the Bolson tortoise and the significance of its preservation. Educational initiatives may focus on local populations, visitors, and the general public to reduce threats like overcollection and habitat destruction.
  • Release Event: Dozens of people gathered for the release of 20 adult tortoises on the Armendaris Ranch, which already hosts 23 adult tortoises and numerous juvenile ones. The release was held in the evening to ensure the well-being of the tortoises due to the hot daytime temperatures.
  • Safe Harbor Agreement: U.S. wildlife officials have finalized a “safe harbor agreement” with Ted Turner’s Endangered Species Fund. This agreement paves the way for the release of more Bolson tortoises on Turner’s ranch, aiming to establish a free-ranging population.