THE BOLSON TORTOISE
The Bolson Tortoise timeline of endangerment- from 1982 to 2022. From endangered, to vulnerable, to critically endangered due to the destruction of their habitat, and the rapid affects of climate change (Keister, 2017).
Why Im Crawling Away?
The Bolson Tortoise is severely threatened by our human activity which is destroying the one place they call home. The dwindling population and potential extinction of the Bolson Tortoise can be understood by the acronym HIPPCO, with each letter standing for a way that their population could be decreased. The main threat of the Bolson Tortoise is habitat destruction and fragmentation, which continues to increase as the human population rises. The urbanization and exploitation is tearing apart their habitat, and climate change (also brought about by humans) is slowly killing these important animals, causing their population to decline by 80% since the 1980’s, in which there were at least 10,000 individuals (Kiester, 2017). The Chihuahuan desert is extremely diverse, and is home to multitudes of animals and plants. This includes over 3,000 species of plants. The desert also contains the Rio-Grande river, which provides water for humans and animals alike, and is a vital resource for the Rio-Grande Basin (“Chihuahuan Desert”, n.d.).
A graphic showing the six components of the acronym "HIPPCO" (HIPPCO, n.d.).
Homeless Bolson Tortoise…
The Bolson Tortoise is endemic to the Chihuahuan Desert in Mexico, but its range has been restricted due to the greed of humans who are overexploiting the desert, and destroying much of the habitat that our tortoise has called home for many years (“Bolson Tortoise'', n.d.). It is restricted to this area because it is unable to migrate, and it is not adapted to live anywhere else (Becerra-López, n.d.). It is now only found in the area where Durango, Chihuahua and Coahuila meet in north central Mexico (“Bolson Tortoise”, n.d.). 43 of the Chihuahuan desert aquifers are exploited (“Chihuahuan Desert”, n.d.), and 100,000 acres of desert have been converted to agricultural land since 2005, causing much of the tortoise’s burow's and territories to be tilled and destroyed. (“Chihuahuan Grasslands”, n.d.).
Other habitat conversions have occurred for railroads, roads, clearing of brush for cattle and federally subsidized ethanol plants for farming. Much of this overexploitation of resources is due to the rise in population in this area. 13 million people inhabit the Rio-Grande Basin, and that number is expected to double in the next 40 years, which shows that the destruction already caused is only a fraction of the harm that could be caused (“Protecting the Chihuahuan”, n.d.). The Rio-Grande river is 150% over allocated for agriculture, taking away the
resource that so many animals rely on, and taking away the ecosystem services that maintain the health of the desert (“Chihuahuan Desert”, n.d.). The Bolson Tortoises struggle to give birth if they do not have adequate space or the right setting. They need to lay their eggs in a small hole they dig outside their burrow. If this space is destroyed, or taken over for agriculture use they cannot reproduce, and their population can not increase (“Gopherus flavomarginatus”, n.d.).They also have personal territories, and when habitat is decreased the this can result in clashes between the tortoises who have to fight for space (“Gopherus flavomarginatus”, n.d.). The loss and fragmentation of habitat is a crucial aspect to the tragic decline of this species, and the destruction of a vital ecosystem: the Chihhuhuan desert. We MUST work together as humans to bring an end to the constant exploitation of our earth’s resources, because it is not worth the harm it causes the animals, ecosystems, and ultimately ourselves.
A bolson tortoise courtesy of Chuta Studios (Chuta Studio, n.d.).
The Chihuhuan Desert in it's degraded state after extreme overexploitation of it's resources. Courtesy of Edward Parker (Parker, n.d.).
Rapid Rising of Heat,
The Repercussions of OUR Actions
The warming temperatures of our planet is causing the death of so many plants and animals, and it is a huge factor in the quickly diminishing Bolson Tortoise. Environmental sex determination (ESD) causes Bolson Tortoises to have thier sex decided by the temperature their eggs are exposed to. Colder temperatures produce males, and slightly warmer temperatures produce females. Because of the heightened temperatures across our planet, less and less males are being born, causing the bolson tortoise to struggle to reproduce (“Turtles and global climate change”, n.d.).This issue will continue to cause less and less tortoises to be able to survive in the wild, and more and more will be forced to be raised in captivity so that the conditions can be changed to support the production of both males and females. This is not a sustainable option, and will not ultimately support the ecosystem in the same way that having a healthy population in the wild will benefit the environment.
Rising temperature is not the only effect of climate change. Climate change can also be the introduction of invasive plants that harm the natives already living in that habitat. Invasives take away resources that would otherwise go to the native plants The Bolson Tortoise relies on Halophytic grass (Hilaria mutica) for 60% of their diet, while the rest is made up of other plants, fruits, flowers and succulents. The decline of this food source slowly kills the tortoises who struggle to find food in the changing environment (“Gopherus flavomarginatus”, n.d.). The bolson tortoise is especially vulnerable in its juvenile years to the effects of climate change, and to predators in its habitat.
A bolson tortoise hatching in the turtle conservancy conservation in Southern California. Courtesy of Manci Rasmussen (Rasmussen, 2021).
The gestation period for the eggs is 75 to 100 days, and they are usually laid in the summer months. It takes 15 minutes for an egg to hatch, which makes them very vulnerable to being harmed as they enter the world. This is increased by the lack of parental care, which causes the baby tortoises to fend for themselves and learn everything they know through their own instincts and experiences. Though each clutch can produce up to 12 offspring, the juvenile tortoises have a 90% mortality rate (due mostly to predation), so their numbers increase very slowly as is, without the external effects of humans (“Gopherus flavomarginatus”, n.d.). We need to take a look at our actions as humans and try to understand the detrimental effects of the industrialization and exploitation of our planet. Not only is the bolson tortoise affected by this, but all animals on the planet, many of which are also facing extinction.
The Bolson Tortoise is being targeted.
In an effort to protect one of the last remaining intact landscapes of this endangered ecosystem, the Mexican government established the Mapimí Biosphere Reserve. Located in an interior basin in Northern Mexico, the reserve is home to 200 bird, 28 mammal, 5 amphibian, and 39 reptile species, including the Bolson Tortoise, North America’s largest terrestrial reptile.
There are many physical and socioeconomic threats to the Bolson Tortoise due to illegal pet trades, predators, building of railroads, deforestation and cattle grazing the land in the Chihuahuan Desert. Many actions have been put into place to conserve the number of Bolson Tortoise. To name one there has been an effort to create an area where cattle grazing is not allowed. The Turtle Conservancy (TC) is working with the support of LDF,” the TC secured 40,000 acres within the Mapimí reserve to create the Bolson Tortoise Ecosystem Preserve. The establishment of the preserve strengthens the protection for the Bolson Tortoise and other biodiversity found there. Along with local partners, TC will manage the preserve and monitor the status of the Bolson Tortoise population to continuously evaluate the effect of their management actions on the long-term viability of this species.“
The desert is filled with tons of different factors that cause nest mortality. Nest mortality is around 87% which means that only about six living hatchlings are produced over 10 years. (Kiester, 2017). There are many different efforts being made to preserve the Bolson Tortoise.
The Chihuahuan Desert biosphere reserve, which is an effort to protect important areas that are threatened by human activities. Courtesy of Jannette Jurado (Jurado, 2015).
A Bolson Tortoise hatching out of its shell, in the Living Desert Zoo and Gardens State Park in Carlsbad, N.M. This park was put into place to restore the depleted populations of the Bolson Tortoise. Courtesy of The Denver Post (Hatching Bolson Tortoise, 2008).
Humans are destroying Bolson Tortoise
Habitats!
There are continuous residential and commercial developments in the Chihuahuan Desert that are destroying the bolson tortoise’s burrows. As well as annual and perennial non-timber crop growth that is taking over the land space of which the tortoises can live. Hunting and terrestrial traps are placed to capture the bolson tortoises which are a harm to them and the other animals that live in the desert.