Rock squirrels are adaptable rodents found across the southwestern United States and Mexico, inhabiting rocky terrains, canyons, and suburban areas. Characterized by their bushy tails and mottled fur, these ground squirrels exhibit a diverse diet, allowing them to thrive in varied environments and utilize available resources opportunistically.
Core Dietary Components
Rock squirrels primarily eat plant-based foods. Their diet includes a wide array of seeds, such as acorns, pine nuts, mesquite, saltbush, agave, wild gourds, and walnuts.
They also forage for various fruits and green vegetation. Juniper berries, cactus fruits, wild sumac berries, cherries, and wild plums are among the fruits they consume. During spring and early summer, they supplement their diet with fresh grasses, plant leaves, and flowers, which provide essential hydration and nutrients.
Supplemental Food Sources
Beyond their plant-based diet, rock squirrels are opportunistic, consuming other food items. They prey on insects like grasshoppers, beetles, caterpillars, and earthworms, which supply protein.
Rock squirrels also consume bird eggs and nestlings, demonstrating their omnivorous capabilities. They may also eat small vertebrates like young wild turkeys and lizards. Carrion and fungi also form part of their diet, particularly when other food sources are scarce.
Seasonal Adaptations in Diet
A rock squirrel’s diet changes with the seasonal availability of food. In early spring, as vegetation emerges, they primarily consume green plants, fresh leaves, and flowers. As spring progresses into summer, fruits and berries become more abundant, forming a larger part of their diet.
In autumn, rock squirrels transition to a diet rich in high-energy seeds and nuts. These items are important for building energy reserves before colder months. During winter, especially in northern regions, they rely on stored food, supplementing it with tree bark, fungi, or available plant material.
Foraging Strategies
Rock squirrels employ various strategies to acquire food, searching on the ground and by climbing trees and bushes. They use their keen senses of smell and sight to locate food. Foraging trips are typically short, with most activity occurring in the cooler morning hours to avoid midday heat.
They use large cheek pouches to transport collected food. These pouches allow them to carry significant quantities back to a den or safe location for consumption or storage.
Caching is a common practice where rock squirrels bury food items, particularly nuts and seeds, for later consumption. This behavior is important for survival during periods of scarcity, such as winter. They possess a spatial memory and an acute sense of smell, enabling them to locate their buried caches even under snow.