by Christopher Yahnke, University of Wisconsin - Stevens Point
Making it to the NCAA men's championship basketball game was the 2nd coolest thing the The Gonzaga Bulldogs did this year. The coolest thing: participating in the Squirrel-Net behavior module. The number of new institutions that have contributed data during this pandemic year was incredible. Right away, I noticed that the Zags observed a number of eastern grey squirrels on their campus. "What!?!”, I thought. Gonzaga is in Spokane, Washington. That can't be right! Time to check Peplinski and Brown.
Between 2015 and 2017, Joy Peplinski and Joel Brown contacted more than 1000 colleges, community colleges, and universities in the United States and Canada asking what squirrelly critters were running around on their campuses. They heard back from 536 campuses and published their findings in a 2020 Journal of Mammalogy paper. In the same way that Dug the dog was distracted by a squirrel in the Pixar movie Up, I was distracted by the first paragraph of Peplinski and Brown. They refer to a paper in the Journal of Irreducible Results called Selecting a College: The Squirrel Index, which is a humorous guide that encourages students to select their college based on the diversity and friendliness of squirrels found on campus.
I thought for sure that the University of Wisconsin - Stevens Point would rate highly based on the Squirrel Index until I learned that Peplinski and Brown excluded flying squirrels from their analysis (come on – every squirrel counts!). They singled out Gustavus Adolphus College in Minnesota as having the most squirrel species (N = 8) of the non-flying variety on any of the surveyed campuses. They also mentioned Sierra Nevada College as a standout for high species richness. When you removed the flying squirrels from the list of squirrels on our campus here in Wisconsin, we were left with what Peplinski and Brown called the “Big Five” (plus we have the little thirteen-lined ground squirrel - so adorable).
The "Big Five" are the species of squirrels found on more than 10% of the campuses surveyed: the eastern grey squirrel (Sciurus carolinensis), eastern fox squirrel (Sciurus niger), American red squirrel (Tamiasciurus hudsonicus), eastern chipmunk (Tamias striatus), and woodchuck (Marmota monax). They predicted three known urban adapters (eastern grey squirrel, eastern fox squirrel, and woodchuck) would be most common on campuses but mentioned little research on American red squirrels as urban adapters. I laughed when I read that research suggested that red squirrels were “indifferent”, “ambivalent”, and “neutral,” regarding urbanization. Talking with my wildlife students that spend time in tree stands, red squirrels are “complainy”, “annoyed”, and generally “pissed off” should a bipedal primate encroach on “their tree”. And then there is the eastern chipmunk - the scourge of the suburban gardener. I can’t even convince my own wife that the chipmunks overwintering under the concrete slab of our back porch are just being resourceful.
Back to Gonzaga, where I learned that it’s indeed the eastern grey squirrel, and not the western that is found on their campus. Figure 4 from the Peplinski and Brown paper clearly shows Spokane is an eastern grey squirrel town (that is, of course, if you know which dot represents Spokane) - mystery solved.
I downloaded the supplementary data that lists squirrel species by campus and both reporting campuses in Spokane also have yellow-bellied marmots. I found it interesting that many campuses had a nearly even mix of tree squirrels and ground squirrels, even some universities that, if memory serves, are renowned for having very few trees.
A quick scroll through the supplementary data revealed few campuses with no squirrels (how depressing - maybe they have other things like snakes or birds, or at least bugs?) One example was Sul Ross State in Alpine, Texas, a pretty campus up the long long road to Big Bend National Park. I do remember seeing rock squirrels and Texas antelope squirrels in the park, they just are not running around on the Alpine campus. In fact, Figure 1 in the Peplinski and Brown paper shows a squirrel desert in west Texas except for the big red blister that is Texas Tech (which is incidentally home to half the world’s mammalogists, so they probably know every squirrel on that campus by name).
Many campuses only have one or two species running around. For example Kansas State, like most Kansas campuses, only has fox squirrels (and maybe a ground squirrel reluctant to leave its cool burrow). The American Society of Mammalogists had their annual meeting at KSU in June 2019 - I think I lost 10 lbs sweating. Walking on campus after lunch, a fox squirrel ran past me into the shade, and hugged a concrete curb. Being from Wisconsin, I’d never seen heat-dumping behavior so beautifully exhibited. I think I heard the squirrel say, “Thank you, Jesus,” or at least that’s what I wrote on my squirrel behavior data sheet.
So, in perhaps one of the greatest contributions to Mammalogy this century, Peplinski and Brown have actually delivered the Campus Squirrel Index they only joked about in the opening paragraph. More importantly, they have used the college campus to paint a delightfully accurate picture of squirrel distributions in North America. Of course they have also provided Squirrel-Net instructors with a resource to identify which species of squirrels can be found on their local campus, should they care to incorporate a squirrel behavioral ecology module into their course. Finally, it’s important to remember that Peplinski and Brown are two others, like all of us at Squirrel-Net, who are passionate about squirrels.
Thank you, Joy and Joel!