What do you do when you are forced out of your home? How do you find another place to live, when the sites you need are already full?
American Pika, small rodent-like rabbit relatives who live in the alpine tundra of the Rocky Mountains, are facing this problem as warmer temperatures force them ever higher. The problem is that there is only so much “up” that pika can go.
Pika are small critters most closely related to rabbits. They have been called “unmercifully cute”, which is probably an understatement.
I spent Saturday in the alpine tundra on Loveland Pass (elevation 11,990 feet, or 3655 m), west of Denver, with scientists from the Denver Zoo and researchers from CU Boulder, learning how to measure pika habitat.
Pika are exquisitely adapted for life in the alpine tundra, where winter temperatures are often 0o F (-18o C), and winds average 50 mph (80 kph). Storms bring blows of 100 mph (160 kph) or more, and drop to -40o F (-40o C). Only a very few animals stay in the tundra through conditions like that: Bighorn sheep, mountain goats, ptarmigan, marmots — and pika. And what’s more pika are active all winter long.
Master of all it surveys — a territory of about 12 meters, or 36 square feet.
How do pika survive these extreme conditions? In a sense, they don’t; they avoid them. Pika live beneath six feet (2 meters) or more of snow. At these depths, the temperature is about 28o F (-1 C) and dead calm. The little critters run through tunnels among the talus rocks to graze on leftover alpine plants. But there aren’t enough of these low-growing plants nearby for pika to survive the winter. So during the fall, the animals gather vegetation and stash it in rock crevasses to build haystacks. They then eat the haystacks throughout the long winter.
A pika gathering forage for it’s hay stack.
The beginnings of a pika hay stack. The Zoo people tell us that by the time the pika is finished, this little crevice will be overflowing with a bushels-worth of hay — about 62 pounds (28 kg) of forage! It takes pika 14,000 trips to gather this much hay.
Here’s the problem for pika: their body temperature is about 104o F (40o C), and they have dense fur to hold this heat in. While this helps them stay warm through the winter, it means they are vulnerable to overheating when temperatures hit 70o F (21o C) in the summer. They can survive short warm spells by descending into the passages beneath the talus. But if pika are chillin’ in the rocks, they aren’t gathering forage to make hay for the winter. As global temperatures rise, pika can overheat, or they can starve. Tough choice.
You can get a sense of how dense pika fur is in this photo.
The one thing pika can’t do is move. Their habitat is limited to the tops of mountains above tree line. If it is suitable for a pika, one already lives there. There isn’t any more.
Scientists at the Denver Zoo want to know how pika are responding as global temperatures rise. So they called for volunteers to come learn how to measure pika habitat. Over forty people showed up at the top of Loveland Pass Saturday morning. After leading us up the alpine trail for a couple of hundred feet, we all sat in a learning circle.
A Denver Zoo staff person explains how the survey works.
We were a bunch of strangers — retired biologists, teachers, a family who wanted to do something together, longtime hikers — but all were passionate about pikas, or Citizen Science. People came prepared, and asked good questions: How big is a pika’s territory? What makes good territory? How did the zoo pick the sites?
We get answers to our questions.
Biologists have a couple of ways to study animals in the field. They can watch them, which takes a lot of time and yields limited information. They can catch them, which is stressful for everybody involved. Or they can study bits of the animal that are left behind — hair, feathers, and even more exciting — animal feces. As a matter of fact, biologists tend to get a little fixated on scat. The animal has no further use for it, and it can tell a scientist a lot.
So we learned how to look for scat, recognize that it was fresh, gather it, and send it to the researchers.
The orange lichen on the foreground rocks is a type that needs more nitrogen. It thrives where pika pee, which makes it a good indicator of pika dens. In the center of the photo is a small pile of pika scat, waiting to be collected by Citizen Scientists.
The researchers can break the little pellets apart and see what the pika are eating. Flowers are higher in protein for growth, while grasses are higher in carbohydrates that provide energy. Another thing that pika scientists can measure is the amount of stress hormones in the scat. If the animals are stressed, they are probably having a harder time surviving. The big reward, though, may be the DNA gathered in the scat. DNA can tell scientists who is moving where, and who doesn’t survive.
Pika fecal pellets glued to the top of a rock with urine. See? I’m fixating.
As the morning progressed, I and the other volunteers put what we had learned to the test. We measured, we crumbled pika poop between our fingers. When we found a hay stack on our own, we whooped with excitement. I had a wonderful day at 12,000 feet, looking for pika with total strangers.
But the funny thing is, they didn’t feel like strangers. As I looked around at the people who were passionate enough about this Citizen Science project to volunteer to spend the day learning how to find pika poop, I saw that they people were just as enthralled with science as I was. I thought “This is my tribe. These are my people.”
So now that I’m trained, it’s time for me to go monitor some pika habitat. I’ll probably wait until September, so that the pika have a chance to gather some hay, and I’ll have a better chance of finding them. But I can hardly wait.