Bolson Tortoise

1 Overview

The Bolson Tortoise is one of the tortoises distributed in North America and the largest of the four remaining North American tortoises. It is very long-lived but has a low survival rate, with only about 3 percent reaching adulthood in the wild. It is occasionally traded in the domestic market.

Chinese name: Bolson Tortoise

Chinese alias: Yellow-margined Gopher Tortoise

English name: Bolson tortoise

Latin name: Gopherus flavomarginatus

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Reptilia

Order: Testudines

Suborder: Cryptodira

Family: Testudinidae

Genus: Gopherus

Species: Bolson Tortoise

Geographic distribution: The Mapimi Basin of the Chihuahuan Desert in Mexico.

Endangered status: CITES.

Reproduction: Oviparous, laying about 12 to 15 eggs at a time.

Size: Adults can reach 45 cm, one of the North American gopher tortoises and the largest of them.

Average lifespan: The Bolson Tortoise is very long-lived; wild individuals are estimated to average 80 to 100 years, and in captivity often exceed a century.

2 Physical Characteristics

The appearance of the Bolson Tortoise is little different from other tortoises, but it is a large tortoise species, with adults reaching 45 cm, among the larger of the gopher tortoises. It likes living in burrows and is timid and cautious.

The Bolson Tortoise is one of the North American gopher tortoises and the largest, with adults easily exceeding 40 cm. It is found only in Mexico, inhabiting the Chihuahuan Desert. The carapace is domed, the hind legs short and stout, the front limbs densely covered with scales and flattened for digging, and all toes are unwebbed. The carapace is oval, brown, somewhat horny, with the center of each scute slightly yellowish. The bridge is well developed with a single axillary scute. The plastron is slightly yellow with brown along the scute edges; the adult’s gular scute extends well beyond the carapace. The head is small, rounded in front, tan slightly reddish, with yellow-green irises. Front and hind feet are about the same size. Males have a concave plastron.

In its native range, indigenous people once used the carapace as a container. As Bolson Tortoise numbers declined, people became aware of the need to protect the species, so fewer now hunt it for tools, and its numbers are slowly increasing.

3 Care Guidelines

The Bolson Tortoise was once near extinction from human hunting, but later people discovered and protected the species, helping incubate, raise, and release them after the danger period, with good results and gradually rising numbers.

Bolson Tortoises were heavily hunted early on, nearly to extinction. In 1973 California biologists surveyed the habitat and found numbers critically low, so in 1976 the Mexican government established a reserve and, with biologists, set up stationed research and a protection plan within it.

The hunters who once specialized in catching tortoises now help biologists find gravid females, settle them in research centers as breeding stock, or find nests and dig out eggs to help incubate them, and hire and train locals to raise the young, releasing them at about 2 to 5 years old. The results are very satisfactory and successful, with a survival rate above 80 percent, and locals take pride in it. Wild numbers are gradually increasing and the future looks more optimistic.

Humans can wipe out a population or protect one; it is all in a single thought. Natural beings and humans share the same law of survival; do not casually hunt such a fragile life.

4 Behavior & Habitat

The defining trait of gopher tortoises is burrow digging, and the Bolson Tortoise is no exception. It is a tortoise that lives in burrows; even with a heavy shell for protection, it still uses burrows for added security.

Like other North American gopher tortoises, the Bolson Tortoise uses burrows to hide. Yet few may know that over 80 percent of all gopher-tortoise burrows are dug by males; females mostly enjoy what the males make. The burrows males dig also create safer habitats for many local creatures, some of which depend on them for survival.

The Bolson Tortoise usually leaves its burrow only in the afternoon, hiding almost the rest of the time. It also becomes dormant in winter or summer. It stores water well, replenishing only during the annual rainy season, so it drinks heavily then, enough to last the whole dry season.

Such is the habit of the Bolson Tortoise; like a bird building a pretty nest, its life revolves around its burrow, a tough yet peaceful way of living that has continued to this day.

5 Feeding Requirements

Keeping the Bolson Tortoise is not very difficult, and it can occasionally be found for sale in some domestic markets. But it is usually large, so do not mix it with other tortoises, and pay attention to some issues when newly acquired.

I. Keep Bolson Tortoises separately

Though armored and seemingly unbothered by collision or pressure, keeping gopher tortoises of different sizes together leads to smaller ones being squeezed and underfed while larger ones dominate. Over time the small ones become thin, fearful, and timid, with risk of death. Keep Bolson Tortoises separate from other tortoises.

II. Notes for newly acquired Bolson Tortoises

Wild Bolson Tortoises often swallow food bearing parasite eggs, becoming carriers. Captive food is processed and less likely to carry parasites, so newly arrived wild individuals need deworming. Second, wild individuals should be given or force-fed a broad-spectrum antiparasitic once in food. Captive-born ones can skip medication until late autumn or early winter, when one dose is given. After medication, worm bodies usually pass in feces within 2 to 3 days.