Nepedia
Back to Discover
Advanced Reader
🧬

Ground squirrel

life science Maturity 5-7 Next article →

Ground squirrels are a diverse group of rodents within the squirrel family, Sciuridae. Unlike many common tree squirrels, most members of this group live on the ground or within underground burrows. The term "ground squirrel" often refers to medium-sized species. However, the group includes much larger animals known as marmots (genus Marmota) and prairie dogs (genus Cynomys). It also includes smaller animals with less bushy tails, commonly called chipmunks (genus Tamias). These animals belong to a biological group called the Marmotini tribe. This tribe is part of the larger Xerinae subfamily and includes six different living genera.

California Ground Squirrel
California Ground Squirrel

These rodents have developed specific behaviors to survive in open environments. Many species are gregarious, meaning they are social and live in colonies with complex structures. They are also remarkably able to stand fully erect on their hind legs for long periods. This upright posture is used for watching their surroundings. In fact, ground squirrels spend about one-third of their time standing. When a predator is visible, they will stop and watch 60% of the time. This watchful behavior helps them monitor potential threats in their habitat.

Marmot-edit1
Marmot-edit1

To defend themselves, ground squirrels use both sound and engineering. When a threat is detected, they emit high-pitched warning calls. These alarm calls act as an early warning system for the entire colony. This allows nearby squirrels to find cover quickly. They also build intricate tunnel systems underground. These burrows feature multiple entrances and various chambers. Some tunnels can reach lengths of up to 10 meters. These complex designs provide many escape routes. The underground chambers make it very difficult for predators to reach them.

Squirrel Mummy
Squirrel Mummy

The evolutionary history of the Marmotini is a subject of scientific study. The oldest fossils of this group date back to the Early Oligocene, more than 30 million years ago (Mya). The genus likely persisted until the mid-Miocene, about 15 Mya. A 20,000-year-old Arctic ground squirrel mummy, known as Palaeosciurus, was found in Europe. This mummy is the oldest known ground squirrel species, though it is not closely related to modern lineages. Scientists are still researching how these animals spread across the world. They may have moved between North America and Eurasia by "island-hopping" across the Bering Straits or the Greenland region.

Squirrel Mummy
Squirrel Mummy

Ground squirrels are found in many different types of habitats. They prefer open areas such as rocky outcrops, fields, and pastures. They also live on sparsely wooded hillsides and grassy areas like parks or golf courses. Their physical size varies significantly depending on the species. Some marmots are among the heaviest squirrels in existence. They can grow to various heights and weights. Their diet is also quite varied because they are omnivores. They eat fungi, nuts, fruits, and seeds. They also occasionally consume insects, eggs, and other small animals.

Scientists categorize these animals into different subtribes based on their relationships. The subtribe Tamiina includes chipmunks, which sometimes spend time in trees. The subtribe Marmotina contains larger animals like marmots and prairie dogs. There is also a subtribe called Spermophilina, which includes "true" ground squirrels like the thirteen-lined ground squirrel (Ictidomys). The fossil record for "true" ground squirrels is less complete than others. It only clearly begins in the mid-Miocene. During this time, modern susliks and prairie dogs were already living in their current ranges.

California Ground Squirrel
California Ground Squirrel

The movement of these squirrels was likely shaped by the environment and competition. While they spread through parts of the Northern Hemisphere, they did not reach Africa. This was likely due to competitive exclusion. This means that close relatives called Protoxerini and Xerini were already living there. These native squirrels evolved at the same time as the Marmotini. This competition prevented the Marmotini from expanding into the African continent. Understanding these patterns helps scientists see how different species interact and occupy different parts of the world.

641 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (3)
File:Squirrel Mummy.jpg
Squirrel Mummy.jpg
File:California Ground Squirrel.jpg
California Ground Squirrel.jpg
File:Marmot-edit1.jpg
Marmot-edit1.jpg
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.