The Bolson tortoise (''Gopherus flavomarginatus''), also called the Mexican giant tortoise or yellow-margined tortoise, is a species of
tortoise
Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like oth ...
from
North America. Of the six North American tortoise species, it is the largest, having a carapace length of about . It lives in a region of the
Chihuahuan Desert
The Chihuahuan Desert ( es, Desierto de Chihuahua, ) is a desert ecoregion designation covering parts of northern Mexico and the southwestern United States. It occupies much of far West Texas, the middle to lower Rio Grande Valley and the lo ...
known as the
Bolsón de Mapimí
The Bolsón de Mapimí is an endorheic, or internal drainage, basin in which no rivers or streams drain to the sea, but rather toward the center of the basin, often terminating in Swamp, swamps and Ephemeral lake, ephemeral lakes. It is located in ...
, which is located in north-central
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
.
Discovery
The Bolson tortoise was discovered only in 1959. The legend is that a group of biologists working in the Bolsón de Mapimí were at a ranch and saw chickens eating out of a large tortoise shell. They inquired about the origin of the shell and the locals responded by saying that it was, "la tortuga grande del desierto", the big turtle of the desert.
In 1979 the 340,000 hectare Mapimi Biosphere Reserve was created to protect the Bolson tortoise and other unique flora and fauna of the Bolsón de Mapimí. Despite this designation, cattle ranching and mining still occur in the reserve. Whether this is detrimental to the tortoise is not known.
Declining population
The most recent research, published in 1991 from data collected in 1983, estimates that fewer than 10,000 tortoises remain in the wild. Populations have declined mostly due to overcollecting for food and the pet trade. Incursion of roads, railroads and agricultural development have accelerated the decline of the species in the last 40 years. In the central portion of its range locals are keenly aware of the tortoise's protected status and aid in its conservation. However, in the northeastern portion of its range, near La Sierra Mojada, populations of the tortoise are low. It is believed that tortoises are still collected and eaten in this area. Additionally, extensive brush clearing operations are being conducted to make way for cattle grazing. In 2008, following the construction of federally subsidized ethanol plants, extensive corn farming operations began within the Mapimi Biosphere Reserve. Farms have been tilled in tortoise habitat, despite its protected status. In 2018, the IUCN Tortoise and Freshwater Turtle Specialist Group recommended a re-assessment and re-classification of all six ''Gopherus'' species. This reclassification would move ''G. flavomarginatus'' from Vulnerable (VU) to Critically Endangered (CR)
Appleton tortoises
In the fall of 2006, 26 Bolson tortoises were translocated from the Audubon Appleton-Whittell Research Ranch in
Elgin, Arizona
Elgin is a census-designated place (CDP) in Santa Cruz County, Arizona, United States. The population was 161 at the 2010 census.
Geography
Elgin is located along the Babocomari River at (31.629095, -110.571951). The Babocomari is known to h ...
to
Ted Turner
Robert Edward "Ted" Turner III (born November 19, 1938) is an American entrepreneur, television producer, media proprietor, and philanthropist. He founded the Cable News Network (CNN), the first 24-hour cable news channel. In addition, he fo ...
's Armendaris Ranch in south-central
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe
, LargestCity = Albuquerque
, LargestMetro = Tiguex
, OfficialLang = None
, Languages = English, Spanish ( New Mexican), Navajo, Ke ...
, a Chihuahuan desert environment within the prehistoric range of this species. These tortoises, known as the Appleton tortoises in commemoration of Ariel Appleton, a champion of Bolson tortoise conservation, were originally brought to Arizona from
Durango, Mexico by Dr. David Morafka in 1973. Four tortoises from the Appleton population were established at the Living Desert Museum in
Carlsbad, New Mexico
Carlsbad ( ) is a city in and the county seat of Eddy County, New Mexico, United States. As of the 2020 census, the city population was 32,238. Carlsbad is centered at the intersection of U.S. Routes 62/180 and 285, and is the principal city ...
. Both locations have active breeding programs in place.
Rewilding
The Bolson tortoise was recently brought to the world's attention when, in August 2005 an, article on
Pleistocene rewilding appeared in the journal ''Nature'' (Donlan, et al., 2005) proposing that
megafauna that became extinct in North America at the close of the
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...
(~12,800 years ago) be reintroduced to the continent to create a
Pleistocene Park
Pleistocene Park (russian: Плейстоценовый парк, Pleystotsenovyy park) is a nature reserve on the Kolyma River south of Chersky in the Sakha Republic, Russia, in northeastern Siberia, where an attempt is being made to re-crea ...
. The Bolson tortoise was the first species proposed for this restoration effort. The tortoise is unique in that, unlike
mammoth
A mammoth is any species of the extinct elephantid genus ''Mammuthus'', one of the many genera that make up the order of trunked mammals called proboscideans. The various species of mammoth were commonly equipped with long, curved tusks an ...
s,
sabre-toothed cats and
giant ground sloth
''Megatherium'' ( ; from Greek () 'great' + () 'beast') is an extinct genus of ground sloths endemic to South America that lived from the Early Pliocene through the end of the Pleistocene. It is best known for the elephant-sized type species ' ...
s, it is not
extinct. The Turner Endangered Species Fund, who re-introduced the tortoise to New Mexico, has made it clear that the restoration of the tortoise to the Southwest is an endangered species recovery project and not a rewilding project, although elements of rewilding exist.
References
* Listed as Vulnerable (VU A1d, B1+2bc, C1 v2.3)
External links
{{Taxonbar , from=Q304573
Gopherus, Bolson Tortoise
Fauna of the Chihuahuan Desert
Reptiles of the United States
Fauna of the Southwestern United States
Reptiles of Mexico
Species endangered by the pet trade
Reptiles described in 1959
Reptiles as pets