Colorado is home to three kinds of tree squirrels: The rusty red fox squirrel; Abert’s squirrel, which has a striking black or gray coat and magnificent ear-tufts; and the smaller but noisier pine squirrel, or chickaree. (Photo from Colorado Parks & Wildlife website, by Michael Seraphin, courtesy of National Park Service)
The lower elevations of Staunton State Park are predominately Ponderosa Pine (Pinus ponderosa) woodlands, with widely spaced trees interspersed with grasses and wildflowers. This is the preferred environment for a healthy population of the Abert’s squirrel (Sciurus aberti ferreus), which is uniquely dependent on this tree species for much of its life. As you can see from the photo, it is also called “tassel-eared” squirrel. In Colorado, it normally has dark gray or black fur, which distinguishes it from other similar subspecies found further south that have white fur on the underside, and more color variations. All the subspecies live between Wyoming and Arizona, and the mountains of Northern Mexico.
Unlike other North American squirrels, Abert’s does not store its food, and the ponderosa pine provides nearly all its food, from seeds in the cones when available, buds, pollen, sap, and the inner bark of twigs in the winter. It will also eat dwarf mistletoe and fungi. It spends much of the day foraging for food in the trees and on the ground below. It has strong hind legs, and can climb easily and jump between tree branches to adjacent trees. It makes nests high in the trees, where large branches attach to the trunk, and also uses witch’s brooms (dense deformations caused by dwarf mistletoe) as ready-made nests.
Mating season is spring, when you may see a number of male squirrels chasing a female in an attempt to mate. After a gestation period of about 43 days, the result is normally a litter of 3 or 4 young, who are nursed and cared for by the mother until they are about 15 weeks old. Fully grown they are 17 to 22 inches long (tail appears to be half their length), and weigh about 20 ounces on average.
They are generally solitary except during mating season, and are not territorial. Their range is up to 200 acres in summer and fall, but limited to about 50 acres during winter. The density of their population in the optimum habitat is 3 to 5 squirrels per 10 acres. The optimum habitat would be described as about 200 mature ponderosa pines per acre of 12” diameter or more.
Abert’s squirrels are hunted in Colorado, and have natural predators including the Northern Goshawk, coyotes, bobcats, and foxes, but their habit of spending most of their time in trees limits the opportunity for ground-based predators. The major long-term danger to their survival is their limited habitat, which is vulnerable to clear cut logging and pine beetle infestation. Their life span in the wild is uncertain, but they can live to about 7 years old in captivity.
Their relationship to the ponderosa pine tree has some fascinating aspects. Where these squirrels are present, their uses of the pine’s assets for food can cause the tree to produce more toxins such as turpenes (which we detect as pine scent) to discourage squirrel activity. The Abert’s seem to prefer trees with lower toxin levels. The trees inhabited by the squirrels also seem to grow slower, but the squirrels is known to spread fungal spores that are essential to the health of the trees.
This cache is located within Staunton State Park, which has one public entrance along S. Elk Creek Road, six miles west of Conifer, about 1.5 miles off U.S. Highway 285. Parking along either side of S. Elk Creek Road and Upper Ranch Road adjacent to the park boundary is prohibited. All vehicles entering the park must have a daily park pass ($10) or a CO state park annual or special pass.
The Park is open year-round, and day use hours at 6:00 am to 10:00 pm. A walk-in campground (up to ¼ mile from parking) is open for public use, and overnight parking is currently permitted only for those staying in the campground. During summer and autumn weekends, the park may reach capacity, and cars are allowed to enter only if a parking space is available. Horse trailers are admitted if space is available for parking trailers in a new, dedicated, unpaved parking area. All Park trails are natural surface, some trails are hiker-only, but other trails are multiuse for bicycles and horses also. Information about the park can be found at Staunton State Park website
All visitors must follow park rules and regulations. These include dogs on leash at all times, clean up after pets, travel on developed trails to the extent feasible, leave no trace, respect areas closed for resource management, and be careful around wildlife (especially mountain lions, coyotes, and black bears). Fires are strictly prohibited, except for camp stoves with an on/off switch in the designated campsites and grilles found in the picnic areas. No motorized vehicles are allowed on trails within the Park. An exception is the special tracked chairs that the Park offers to visitors who cannot access selected trails on their own mobility. Pack your own trash out of the back country, and trash receptacles are located near the parking areas. Also, be prepared for changing weather, bring adequate water and footwear, and trails may be snow-covered or icy in winter.