Karli Weatherill was a Colorado Mesa University sophomore when she showed up at the office of Johanna Varner and voiced an interest in doing scientific research in the mountains.
As it happened, Varner, an associate professor of biology, had a field trip planned the upcoming weekend in the La Sal Mountains outside Moab as part of her long involvement with researching American pikas. She invited Weatherill to join her and a fellow researcher.
“She said, ‘yes, sounds great,’” Varner recalls.
The trip was anything but, Varner recalls.
“It was basically a comedy of errors,” Varner remembers.
The outing involved difficulties such as negotiating unexpected roadwork, having to do some walking to get to a subpar campsite Varner’s vehicle couldn’t quite reach, and coping with an unexpectedly cold September night and early morning, followed by an unexpectedly long 12 hours of field work.
“Karli was really cold and she was really hungry,” said Varner.
“… I was just thinking to myself, well, that’s too bad because this student just seemed like she was really enthusiastic and motivated and now she’s not going to want to do this. And when I dropped her off she was like, ‘That was fun, let’s do it again.’”
“That’s when I thought to myself, this is going to be great,” Varner recalled with a laugh. “I thought, if this person thinks that that was fun, she’s going to be successful in alpine field work.”
Thanks to some hard work, that success hasn’t taken long to arrive for Weatherill. By her senior year, she was writing the draft of a research paper investigating how climate and habitat affect stress among La Sal pikas. That’s important because high stress levels can be an early indicator of vulnerability before a pika population disappears.
That peer-reviewed paper is now being published in Western North American Naturalist. It found that over a research period of 2018-23, pikas were most stressed in hot, dry years, but at the individual level, having more grass for forage in a pika’s territory may buffer that stress.
“It was a really cool experience. I was involved in the lab work, the field work and all the writing and everything that went into the publication process,” Weatherill said.
Varner said it is fairly unusual for a student to lead such an undertaking at a big research institution, let alone somewhere where research isn’t as big a focus of either the faculty or student experience.
“I think that speaks to both Karli’s time management skills and her determination, and she also has some pretty exceptional writing and thinking skills,” she said.
Varner said Weatherill had a lot of support from her and all the other coauthors of the paper, “but it was really a student-led endeavor.” The paper is expected to go live online today at https://scholarsarchive.byu.edu/wnan/vol86/iss2/1.
STRESS TEST
Pikas are small relatives of rabbits that live in alpine terrain. Varner began the research that resulted in the paper before Weatherill had even started college. It involved trapping and marking 74 pikas and measuring their stress levels, sometimes over multiple years when researchers were able to spot them again. Researchers were able to measure stress by collecting pika scat in each of the pikas’ territories and measuring metabolized stress hormones in the scat.
Among other things, researchers found that higher average August temperatures were associated with increased stress metabolite levels. The paper notes that warmer temperatures may cause pikas to restrict their foraging to the cooler parts of the day, resulting in smaller food caches for winter.
LOW SNOW WOES
The study results also suggested that on a population level, pikas were most stressed in years with the least snowpack. Varner said those high stress levels showed up the summer after low-snowpack years.
A possible reason for this is that snowpack acts as an insulating blanket for the animals living beneath it during the winters.
“So ironically in years where there’s lower snowpack, the animals actually are exposed to the colder surface temperatures because they don’t have this layer of insulation,” Varner said.
She said that could mean they have to ramp up their metabolism to stay warm, and go through their cached food source too fast.
A concern is that declining snowpack in the West could exacerbate this problem, also reducing availability of snow as a source of water for pikas, which Varner said the animals mostly get through the vegetation they eat. Varner said that with this winter’s particularly low snowpack, in many places there are areas in the talus fields where pikas live that weren’t completely covered with snow, meaning the cold surface temperatures could get through uncovered holes between rocks.
With the researchers’ work continuing in the La Sal Mountains, “I think it will be really interesting to see what we find this year given the kind of exceptional conditions that the mountain West, across the mountain West, is experiencing,” Varner said. “… We hope the consequences won’t be too dire for (the La Sal pikas).”
Varner thinks less snowpack also could mean less growth of the vegetation that pikas rely on.
A key finding in the study was that while average population-level stress levels were higher in hot, dry years and lower in colder years, pikas with more grass in their territories tended to have lower stress levels than everyone else in the populations.
For land managers, that could be useful information in terms of helping protect pikas. Varner said that while it’s harder for local land management units to take on stopping climate change, as important as that is, they can work on managing grass cover in pika areas. In the La Sal Mountains, for example, livestock grazing occurs in areas where there are pikas. Varner said while more experiments would be needed to determine any effects of grazing on pika grass cover, it could turn out that managing herbivores, especially livestock, that compete with pikas for grasses could be one meaningful thing that could be done to help with pika conservation.
A LOVE OF FIELD SCIENCE
Despite the difficulties of her first field outing, Weatherill said they were overshadowed by the parts she enjoyed. She’s from Cañon City, and spent a lot of time in the outdoors growing up, enjoying hiking and the alpine environment.
“I thought it was cool that my professor invited me to go out and go camping and then do science … and then it was just a team of all women, which I had never really seen a group of women hanging out and going to do science to try to protect and understand this cute little mammal that lived up there,” she said.
“I just thought it was cool to be hanging out with bunch of cool people in the mountains.”
Weatherill ended up being funded to do field work in the La Sal Mountains for two summers through the Saccomanno Internship Program in Biological Research, which is funded by the Saccomanno Higher Education Foundation. Josey King, Tabitha McFarland and Holly Nelson, who are among the co-authors on the pika study, also worked through the internship program.
Other CMU students helped the research through means such as doing engineering work to design housing for data loggers used to record temperatures at the research sites, and conducting genetic testing from extracted DNA to determine the gender of pikas being studied. Varner said a number of CMU faculty also helped in the field and otherwise with the study.
Weatherill said writing the study paper was one of the most challenging things she’s ever done, particularly as she balanced being a full-time student.
But she added, “I think I was very supported throughout all of it and it was a really cool experience, and I think it also solidified my want to go on to graduate school for sure.”
After getting her bachelor’s degree in ecology, evolution and organismal biology last year, she took a gap year, during which time she has been able to finish up the editing and final submission of the pika paper and work on applying to graduate programs. She will be heading to the University of Oklahoma next fall to pursue a PhD, and is hoping to continue studying alpine systems and small mammals such as pikas that live in those systems.
Weatherill said she remembers learning in the fifth grade about the hole in the ozone, and realizing how big an impact humans can have on the planet. That made her think about how people can take responsibility for that.
“I think research is one of the ways that we can try to further understand our impact and what we can do to try to reverse that impact. That’s a lot of what motivates me, other than being able to hike around and look at cute animals all day,” she said, laughing.
“Which is a good perk,” Varner interjected.
Said Weatherill, “Yeah, it’s a great perk. It’s like recreating but also making a difference.”
‘COMPLICATED STORY’
Ironically, the research into climate impacts on pikas in the La Sal Mountains was impacted when the Pack Creek Fire in 2021 blocked access to research sites and burned up to them but stopped short, Varner said.
Across the range of pikas, the strongest climate-change-related declines are being seen at lower-elevation, isolated, small mountain ranges pretty far south in the animal’s distribution, Varner noted. While the La Sal Mountains check all those boxes, Varner said there appear to still be lot of pikas there and at least the ones she and colleagues have been working with appear to be in good physical condition.
Despite declines in pikas in some parts of their overall range, they also have proven in some areas to be more resilient, accommodating environmental changes by changing their behavior, such as through shifts in their diet and moving around their territories to make the best use of microclimates, she said.
While pikas rightly get a lot of press about being canaries in the coal mine and supersensitive to climate change, “it’s also a much more complicated story than that and I think that makes it really interesting,” Varner said.
She notes that members of the public who are interested in contributing to pika-related observations in the field can do so by downloading and using the free Pika Patrol app, which she helped develop and can be found at https://pikapartners.org/.