Ear tufts that come and go with the seasons
An Abert’s squirrel is heavy-bodied for a tree squirrel, gray above with a rusty saddle and a clean white belly, but the build isn’t what identifies it. It’s the ear tufts: long, dark, and pointed, growing into dramatic black plumes through the cold months, then shrinking to almost nothing by late summer. A squirrel photographed in January and one photographed in July can look like two different animals.
Coat color varies even more than the tufts do. Many populations run heavily melanistic, all black from nose to tail, and some ranges produce paler or browner squirrels. What stays constant is the pairing of long ear tufts with a two-tone tail, gray on top and white underneath.
Four other Southwestern squirrels get mistaken for it, and none of them wears tassels. The Arizona gray squirrel is smoother gray with no tufts at all. The Mexican fox squirrel has rusty-orange underparts instead of a white belly. Fremont’s squirrel is much smaller, red-backed, and noisy. The fox squirrel that has spread into lowland towns is tawny below with a bushy rust tail.
A forest specialist bound to one pine belt
No North American tree squirrel depends on a single conifer the way this one depends on ponderosa pine. It eats the tree’s cones and inner bark, nests in its crown, and rarely comes down when a better route exists overhead. Ponderosa doesn’t grow as one continuous forest. It wraps individual mountains and plateaus in a mid-elevation belt and skips the low desert between them. The squirrel’s range reads as a scatter of forested islands rather than a solid block.
Those islands sit across Arizona and New Mexico, the southern Rockies of Colorado, and the high plateaus of Utah, a Four Corners story more than any single state’s. It also turns up in pinyon-juniper woodland, mixed conifer forest, and pine-shaded mountain towns wherever enough canopy remains. Records cluster hardest inside the ponderosa belt itself and thin out fast above and below it.
Separated by desert the squirrel can’t cross on its own, isolated populations drift apart over time. Wildlife agencies have used that in reverse, moving squirrels onto pine ranges they’d never reach unassisted, including several of Arizona’s sky islands, where the transplants took hold.
The truffle a whole forest depends on
Diet stays narrow but shifts with the season: seeds and cones first, especially pinyon and ponderosa, then buds and pollen-cones in spring, then the sweet inner bark of twigs once the cone crop runs out, plus occasional insects and fungi. Bright piles of bark-stripped twigs under a pine in winter are the surest sign an Abert’s squirrel has been at work.
The fungi matter more than they sound. Ponderosa roots depend on soil fungi to draw water and nutrients, and many of those fungi fruit underground as truffles that can’t scatter their own spores. The squirrel digs them up, eats them heavily when other food runs short, and carries the still-viable spores across the forest floor in its droppings. It’s one of the better-documented mammal-and-fungus partnerships in the West.
A squirrel that feeds by day in open pine crowns is exposed. Hawks and other predators hunt from the air, and a raven will take what it can from an unwary one.
Solitary in the canopy, then briefly not
Abert’s squirrels are active by day, year-round, and they don’t hibernate; in hard weather they just hole up in a nest for a day or two and wait it out. Each one builds one or more bulky nests of twigs and needles high in a living ponderosa, and uses a tree cavity when it finds one. Outside the breeding season it lives a largely solitary life.
That changes in late winter and spring, when a receptive female draws a string of males into long, headlong chases through the canopy. Young are born blind and helpless in the treetop nest, stay there for weeks before venturing onto nearby branches, and are weaned soon after. A female usually raises one litter a year, occasionally two, and most squirrels don’t live many years in the wild, though captive individuals can live considerably longer.
The white-tailed squirrel of the Grand Canyon
The most distinctive Abert’s squirrels live on the Kaibab Plateau, on the North Rim of the Grand Canyon. Walled off by the canyon on one side and by desert on the others, that population evolved into a strikingly dark, almost black-bodied squirrel with a pure white tail. It’s different enough that some authorities treat it as its own subspecies. Visitors to the North Rim’s meadows and pine stands see them regularly in summer.
The Kaibab squirrel is really an extreme case of a pattern that plays out across the whole range. Because each pine island holds its own semi-isolated population, coat and tail color vary noticeably from one mountain range to the next.
Fire is the real threat now
Abert’s squirrel is listed as Least Concern, and it remains widespread wherever mature ponderosa stands persist. The catch is that its whole life is bound up in one forest type, and that forest is under growing pressure. Stand-replacing wildfire is the single biggest threat, and it’s grown more frequent and severe across the Southwest in recent decades. A severe burn can turn mature pine into open shrubland for decades, erasing food and travel routes at once.
Heavy logging of older, cone-bearing pines does similar damage more slowly, and drought or bark-beetle die-offs thin the food supply in bad years. Forests managed for a mix of tree ages, good cone crops, and connected canopy keep populations steady. Road strikes, dogs, and fragmentation near recreation sites add smaller pressure around the edges. This squirrel’s future, in the end, tracks the health of the ponderosa forest it can’t live without.
