Musings of a New Naturalist: Picky Eaters
Abert’s squirrel (Sciurus aberti)
At a scenic lookout above Boulder, a former quarry for glinting slabs of ancient sandstone, I came upon pinecones nibbled round like ears of corn. Some were chewed bare, save a few scales poking out of the top; others had a few of their scales still dangling from fibrous threads. I instantly knew, from my naturalist training, who had chewed these cones – an Abert’s squirrel, one of the many critters new to me in my new home.
As they are shy and have larger home ranges than other squirrels, seeing an Abert’s squirrel is a special treat. Black fur (the dominant coat color in this area) and prominent ear tuffs distinguish them from other squirrels and chipmunks. One popped up from behind a log, as if on cue, during one of our trainings on the ponderosa pine ecosystem. I’ve only spotted a handful of them in the year and a half since then.
Compared to Eastern gray squirrels, who’ve moved into the area and eat everything from boxelder seeds to apples to our Halloween pumpkins, the Abert’s squirrel is a picky eater. A very picky eater! A specialist. These squirrels dine, almost exclusively, year-round on pieces and parts of ponderosa pine – the inner bark of twigs (especially in winter), pollen in the spring, cones and their seeds as long as they last. They even sniff out and eat the mycorrhizal fungi that associate with ponderosa pine roots beneath the soil. In return for food, shelter, nesting sites, and escape routes, these squirrels help regenerate the forest by spreading seeds and fungi.
I didn’t see an Abert’s squirrel that day at the old quarry, but I began to wonder about the risks of being such a picky eater. Imagine relying on only one food source! I sense that picky eaters will need extra attention and protection in a changing world.