What’s Going On Down There?
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Anyone who spends even a few hours walking around our local desert will soon discover that the place is full of holes. Seemingly, everyone digs burrows or lives in them. Observing all of the burrows and tunnels gives one the sensation that the life that is observed on the surface represents just the tip of the iceberg. And, not only are there holes, but an observer will also notice that there seem to be many mounds of dirt that are without visible entrances, strange piles of earth that sit out on the desert floor for no apparent reason.
What are these odd piles and who’s making them? Well, as it turns out, they are sealed up entrances to tunnels. They are made by Botta’s Pocket Gophers, representatives of a southwestern species of pocket gopher that spends nearly its entire existence underground.
Botta’s Pocket Gophers are heroic diggers. They dig immense personal burrows. One of these rodents can produce tunnels that are tens of yards long. It spends its life living beneath the surface, digging openings to its burrow that it will use for foraging for vegetation. It has a unique style of foraging. It will pop up from a tunnel, harvest all of the plant material that is within reach, then descend into its burrow after sealing up the hole that it has made. That’s what those little mounds are all about.
People literally never see these animals. They are shy and secretive and will not emerge if they believe that they are under observation. But, this morning I had the amazing good fortune of being able to observe not one, but two Botta’s Pocket Gophers. I was walking in Ft. Lowell Park — an urban park in Tucson — when I suddenly saw a small animal pop up from a hole at the edge of the park’s pond. It was a Botta’s Pocket Gopher and I observed and photographed it for several minutes while it harvested plants adjacent to the hole.
The gopher was about the size of a domestic Guinea Pig. As is typical of this animal, it never emerged completely from the hole, always keeping its hindquarters in the tunnel entrance so as to enable a quick escape.
Pocket Gophers have external cheek pouches in which they can store large quantities of food. This individual was obviously stuffing itself as I observed it.
Botta’s Pocket Gophers have tiny eyes. Undoubtedly vision is not an especially important sense for these creatures, who spend nearly their entire lives in darkness. They come in a tremendous variety of colors ranging from nearly black to pale gray. This individual is a sleek brown with a whitish stripe on its back.
These are solitary creatures. They do not socialize with others of their species except to breed. They are sexually dimorphic: a male can be nearly twice the size of a female. To my surprise and pleasure, I saw a second gopher pop up out of the ground a few feet away from the first one. This one was much lighter in color than the first individual and much smaller. My guess is that the first individual is a male and the second, a female, perhaps his mate. Pocket gophers do associate to breed, of course, but they don’t stay together. Perhaps these two were associating only for breeding purposes? The female briefly showed off her huge incisors as I photographed her. Those are impressive teeth and they show why these animals are so good at harvesting plants. Those giant incisors are also primary digging tools for the gophers. These animals can expose their front teeth while sealing off their mouths, thus enabling digging without getting mouthfuls of dirt.
Images taken with a Canon 5Diii, 400 DO+1.4X Extender, ISO 800, aperture preferred setting, f7.1, shutter speeds varied.