Ground squirrels are active, burrowing rodents whose diet changes dramatically from birth to adulthood. Pups spend their existence entirely underground, relying solely on their mother’s milk for sustenance and growth. This strict liquid diet rapidly progresses to a complex omnivorous diet as they mature. The transition to an independent, foraging life requires a specific and carefully timed nutritional shift.
The Nursing Phase: Maternal Milk Dependence
A newborn ground squirrel is born completely helpless (altricial), meaning it is blind, hairless, and fully reliant on its mother for warmth and nutrition. For the first few weeks of life, the pup’s diet is exclusively maternal milk. This highly specialized substance is designed for rapid subterranean growth and changes composition over the course of lactation to meet the pup’s evolving needs.
Studies show that ground squirrel milk is uniquely adapted for a short, fast-paced development cycle before the young must hibernate. The milk is notably high in protein and calcium compared to many other rodent species’ milk. This high protein concentration promotes fast growth rates, increasing the likelihood of juvenile survival through their first winter hibernation period.
The calcium content is particularly high, possibly serving as a preventive measure against bone mineral loss during their long hibernation state. While fat content can vary, the overall nutrient density fuels the young squirrel’s intense developmental phase within the burrow. Pups typically nurse for four to six weeks before their eyes open and they begin to explore outside the nest.
The Weaning Period: Transition to Foraging
The weaning phase marks a gradual shift in the baby ground squirrel’s diet, moving away from milk toward solid foods that resemble the adult diet. This transition usually begins while the pups are still in the burrow, shortly after their eyes open, around four to six weeks of age. The first solid foods they consume are typically the most tender, accessible plant parts found near the entrance or brought into the burrow.
Initial solid foods include soft, fresh plant matter like young grass shoots, flower buds, and roots. Ground squirrels are primarily herbivorous but are also opportunists. Their diet rapidly expands to include seeds, grains, and small invertebrates like insects. The mother often guides this process by bringing in appropriate food items and demonstrating how to eat them.
As the pups venture above ground, their diet diversifies further, incorporating berries, fungi, and succulent vegetation. Fresh plant matter is an important source of hydration, as the pups are still learning to seek out and drink water independently. By eight to ten weeks old, young ground squirrels are typically fully weaned and their diet is virtually indistinguishable from that of an adult.
Assisting an Orphaned or Found Baby Ground Squirrel
Finding a baby ground squirrel separated from its mother requires immediate action, and the first priority is always warmth, not food. A cold infant cannot digest food properly, and feeding it formula or milk can lead to aspiration pneumonia, which is often fatal. The animal must first be warmed using a safe heat source, such as a water bottle wrapped in a towel, or a sock filled with uncooked rice and microwaved.
Once the pup is warm, the second concern is dehydration, which is common in orphaned wildlife. Before any milk is offered, the squirrel needs a temporary rehydration solution, such as a mix of water, salt, and sugar, or a commercial electrolyte solution. This fluid must be administered slowly using a small syringe while the squirrel is held upright, preventing accidental inhalation of the liquid.
Avoid common household liquids like cow’s milk, goat’s milk, or human baby formula. These lack the necessary fat and protein ratios and contain high levels of lactose that ground squirrels cannot digest. Ingesting inappropriate substances can cause severe diarrhea, leading to fatal dehydration and intestinal distress. A specialized, species-appropriate milk replacer, often available through wildlife centers, is the only suitable nutritional substitute.
The most responsible action is to contact a licensed wildlife rehabilitator immediately. They possess the permits, expertise, and specialized formulas necessary for proper care. Attempting to raise a baby ground squirrel without professional guidance often results in nutritional deficiencies, such as metabolic bone disease, or improper weaning. Rehabilitators can also advise on stimulating urination and defecation after feeding, a necessary task for young pups that cannot eliminate waste on their own.