The Ground Squirrels of Idaho 

Discover the unexpected thrill of small mammal research.

By Grace Vaziri. Photographs by Amanda Goldberg.

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The Northern Idaho Ground Squirrel (NIDGS) is a federally threatened species under the Endangered Species Act. It occurs in only two counties in West-Central Idaho, and is one of the rarest small mammals in North America. Northern Idaho Ground Squirrels are a species in peril, and yet as I held one for the first time, my main concern was how unbelievably adorable I found the tiny mammal quivering in my hands. I study small mammals because they are ubiquitous wherever humans occur, because they convey a wealth of information about the health of ecosystems and the spread of disease, and because they are just plain cute.

Admittedly, ground squirrels aren’t the stuff of National Geographic covers. Nor does the study of small mammals often make for fantastic tales of danger and suspense– no close run-ins with grizzly bears or hungry anacondas here. Ask me about studying small mammals and you might hear the story of the time I combed 83 fleas off a single Columbian ground squirrel (dirty lady!) or the time I was so disgusted by the botfly infestation on a chipmunk’s face that I made my research partner do all the chipmunk handling alone.

When I tell people that I study squirrels, I am customarily rewarded with quizzical nods and mutters of polite confusion. Call it the chipmunk on my shoulder, but I’m ready for biologists and laypeople alike to recognize the incredible feats performed by small mammals everywhere. Charismatic mega-mammals step aside, your little cousins the rodents are ready for their close-up.  

As a biologist fascinated by small mammals (fondly referred to as smammals), I often find myself justifying my area of study to biologists and non-biologists alike who wonder, “why not wolves, or bears, or eagles?” What they are really asking is “why something so boring?” I understand their confusion though, because until you pause to appreciate the commitment it takes for a Northern Idaho Ground Squirrel to sleep for eight months of the year, or the incredible effort and diligence a Dusky-footed Woodrat puts into creating a perfect multi-chambered multi-level nest for its young, or the lifelong courtship of the California mouse (with greater fidelity than that seen even in birds), it might be easy to write off smammals as simply being pesky plague-bearers.

If your interest in smammals starts and ends with disgust or disinterest, allow me to convert you. When I moved to West-Central Idaho last summer to work on a project studying the demography of Northern Idaho Ground Squirrels, I imagined I might quickly become bored of the project, but that was not the case. In the four months I spent capturing, marking, and recapturing squirrels in the forests and meadows of Idaho, I learned to appreciate the rat-race it is to live life as a Northern Idaho Ground Squirrel. Challenges include the following:

1. Obtain enough nutrition in your four waking months to get you through 8 months of hibernation.
2. Avoid being eaten by weasels, badgers, hawks, eagles, coyotes, bobcats, and the rancher’s dog.
3. Consume the perfect ratio of poly-unsaturated fatty acids to repress your metabolism throughout your hibernation, and forage for these essential foods in the sparsely vegetated areas left to you by your greedy evolutionary cousins, the Columbian Ground Squirrels.
4. Do all these things while producing a litter of baby squirrels that you (if you are a female NIDGS) will rear in less than four months.

NIDGS aren’t the only small mammals worth talking about, however. Another species of small mammal, the deer mouse (Peromyscus maniculatus), is found almost everywhere in the U.S., and is a vector and carrier for diseases like hantavirus, and Lyme disease.

Anyone familiar with the early '90s outbreak of the Sin Nombre virus in the Four Corners region of the U.S. might know that deer mice were quickly identified as the host of the virus that caused the outbreak. The deer mouse lobby was recently encouraged by the acquittal of the black rat in the plague case from Europe, and is looking for local populations of gerbil analogs on which to pin the Sin Nombre blame.

P. man, tough little mouse that it is, makes its home everywhere from the non-native eucalyptus stands of the Berkeley hills in California, to the Ponderosa Pine savannahs of Idaho, to the deciduous forests of New England. In my opinion, anywhere that deer mice exist there also exist opportunities to ask questions about emerging infectious disease transmission and the impacts of invasive plant species on small mammal habitats. In fact, during the summer of 2015, I will be working to help collect data to determine whether bubonic plague is present in habitats shared by deer mice and NIDGS.

When I moved back to California last year, after the NIDGSs had entered hibernation, I swore I wouldn’t return to Idaho. Too exhausting, I thought. Keeping up with those squirrels through hilly hectares of sagebrush and snowberry, chasing them from dawn to dusk in heat and sleet till I swore my feet would fall off. That was fun one time, but not something I needed to do again. But like a moth to a flame (or a mouse to peanut butter?), I found myself signing on to return to Idaho this year.

I could say that the endless spread of Ponderosa-covered mountains or the lingering possibility of a coveted wolf-encounter drew me back to Idaho. But maybe it was just the delight of observing the industrious NIDGSs scurrying away that drew me back. When I return to Idaho this spring my fingers will be crossed in hopes that lots of juvenile squirrels, squirrels I met last year, made it through the winter. Until then, I’ll be as busy as a squirrel in a bag of nuts, telling anyone who will listen about the excitement and intrigue inherent in the world of small mammals.

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Grace graduated with a bachelor’s degree from UC Berkeley in 2013 and now spends her summers working as a biology technician for the University of Idaho. In addition to chasing squirrels down holes, Grace enjoys working as a dog walker in San Francisco. When she goes back to school she plans on studying the impacts of habitat fragmentation and invasive vegetation species on small mammal communities. Reach her at

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