Slow but Mighty: The Desert Tortoise of the Mojave

Most of us are familiar with tortoises, but what are Desert Tortoises? 

Desert Tortoises, Gopherus agassizii, are slow-moving reptiles just like other tortoises, but they are native to the Southwest of the US and Northwest Mexico. These guys have thrived in the harsh Mojave Desert ecosystem for millions of years and have adapted to severe desert temperatures that make them extremely resilient. Appearance-wise, desert tortoises have a dome-shaped shell, which is typically tan or dark brown in color. They have heavily scaled front claws used for burrowing and relatively long rear legs. Male desert tortoises have longer tails than female desert tortoises, and males have a concave shaped underbelly. 

A baby desert tortoise, fitting in the palm of a hand. Photo Credits: www.tortoiseclub.org 

Life as a Young Desert Tortoise 

Desert tortoises begin life as tiny hatchlings in the sand, typically born during the late summer or early fall, measure just about 2 inches in length and weigh- only a few ounces. In their youth, they feed on insects, greens, flowers and snails. But,during this time, their shells are soft which makes them easy prey for their predators, so they are extremely vulnerable. Because of this, very few baby tortoises survive to adulthood. 

Adaptations and Characteristics: How do they survive? 

Before we get into their adaptations, let’s lay out the size guide of these tortoises. Adult desert tortoises can grow up to 14 inches in length and weigh anywhere between 8 to 15 pounds. But their growing process is about as slow as they move, because it can take on average 16 years for a desert tortoise to reach just 8 inches! 

What helps them survive the brutal conditions of their habitat is their digging skills. As I mentioned before, they have sharp claws that allow them to dig burrows in the tough desert terrain. To escape the extreme desert temperatures, desert tortoises spend up to 95% of their lives in burrows, and these burrows can be up to 30 feet long. These burrows provide shelter from both extreme heat and cold, especially during winter when tortoises enter brumation, a hibernation-like state that cold-blooded animals, such as reptiles, use to survive low temperatures.These tortoises are herbivores, feeding on a variety of desert plants, including grasses, wildflowers, and cacti, and can even go 3-6 months without food. On top of that, they can survive up to a year without fresh water by storing water in their bladders and reabsorbing it when needed. 

A Desert Tortoise feeding on the flower of a cacti. Photo Credits: www.reptilefact.com 

Overall Importance 

In addition to being a fascinating animal, Desert Tortoises are actually a keystone species, meaning they play a crucial role in balancing the ecosystem around them. For example, their burrow system benefits other desert animals such as lizards, snakes, and birds, because they are creating habitats for them as well. We can think of them as animal architects, because they create a home in the rugged landscape that provides a safe space for other animals to live. Another important role they play in our ecosystem is seed dispersal. Since they are herbivores, the seeds they ingest are excreted in their feces, planting seeds and fertilizing the soil. They are also indicators of the health of the ecosystem; if the desert tortoise population is declining it can often mean that climate change or an overpopulation of predators is causing it. 

A desert tortoise emerging from one of its burrows. Photo Credits: www.kids.nationalgeographic.com 

Fun Facts About Desert Tortoises 

• Their lifespan ranges from 30 to 50 years in the wild, but some have even been recorded to live past 80 years 

• They dig shallow pits to collect rainwater, returning to these spots after storms to drink 

• As many as 25 desert tortoises can bunk together in one shelter 

• Sometimes when males come across each other, they’ll fight to establish dominance. They use the horns on their chests to try and knock each other over; the fight is over when one animal flips the other on its back, and it takes quite some effort to flip back over.

A Call to Protect 

Despite their resilience, desert tortoises face numerous threats that have led to a dramatic decline in their populations. Since 1950, their numbers have decreased by an estimated 90%. This is mainly due to human intervention whether it’s urban development or the introduction of more predators like ravens, eagles, coyotes, etc. 

Here are 4 main points to aid in conserving our Desert Tortoises 

1. Education and awareness is the 1st step to conservation 

2. Support conservation efforts, the U.S Fish & Wildlife Service has The Desert Tortoise Recovery Office that works to provide effective and coordinated recovery, research, and monitoring activities for the Mojave desert tortoise

3. Let the wild be wild, do not interfere with our desert tortoises and allow them to live as they should be 

4. Reduce human waste that attracts predators of the desert tortoise, ravens, for example, love food scraps but are also a main predator of young desert tortoises 

I hope we can all join forces and protect our desert tortoises, and ensure they continue to thrive in their natural habitats!