LIFE (AND DEATH) IN THE TALUS FIELD

July 16, 2009  •  Leave a Comment



LIFE (AND DEATH) IN THE TALUS FIELD
©Jay Ryser www.jayryser.com
Wildlife, Landscape, and Nature Photography Online Magazine


To the casual observer, a talus field is a large jumble of oddly-shaped rocks that have collected at the base of a mountain slope. To anyone who has ever tried to ascend or descend a talus slope, particularly while wearing a heavy pack, it’s a dangerous area where one misstep on a poorly balanced rock can pitch you dangerously into a world of hurt. It’s slow going, and treacherous footing – most people and many animals avoid talus field when they can.

Talus is another word for scree – a collection of broken rock fragments that have broken away from a higher cliff or mountain slope as a result of weathering and erosion. Talus can range in size from golf ball-sized stones to chunks of rock the size of VW Beetles. Technically, scree is smaller than talus, ranging in size from gravel to small stones. Because of the irregular size of the rock fragments, there can be quite a bit of space between the rocks, making talus slopes an ideal home for a variety of small animals.

The alpine zone (mountainous regions above tree-line), is a unique ecosystem characterized by intense weather conditions, a very brief Summer growing season, hardy vegetation, and animals with specialized survival skills. Many talus fields are found in the alpine zone. Two of those species of animals with specialized survival skills happen to be two of my favorite animals – pikas and marmots.
American Pikas (Ochotona princeps) and Yellow-Bellied Marmots (Marmota flaviventris) are two of the more common species inhabiting the talus field, and two species highly adapted to this extreme environment.

Marmots
Marmots are essentially high-altitude ground hogs. The name marmot comes from French marmotte, from Old French marmotan, marmontaine, from Old Franco-Provençal, from Low Latin mures montani “mountain mouse”, from Latin mures monti, from Classical Latin mures alpini “Alps mouse”. Marmots are also called “whistle pigs,” “rock chuck,” and my favorite nickname, “brake-line chewers.” In North America, marmots inhabit mountainous terrain in the western ranges, including the Sierra Nevada and the Rocky Mountains. Other varieties of marmots can be found in similar locales in Europe and Asia.



I have not always been so kindly disposed to marmots. In my younger and more adventurous days, I’ve had ropes and harnesses chewed upon during alpine bivvies, and once very nearly rappelled using a nearly chewed-through rope. I’ve even been known to chase a marmot with an ice ax, without good intentions, after catching one chewing through my pack. Since that time we’ve managed to put aside some of our old conflicts and have actually become quite chummy. How can you stay mad at something so cute?

Marmots get the nickname “whistle pig” from their habit of whistling, hooting, or squeaking out a warning to their neighbors if predators are present. Marmots therefore have the reputation as being one of the few truly altruistic species on the planet – they keep themselves in danger to warn their peers. Marmots are also apparently Mormons (or LDS, if you prefer). One dominant male can share a burrow with 3, 4, or more females, and breed with all of them. Marmots are very skilled burrowers, and can construct a complex system of rooms and tunnels under the talus, including toilet areas, dining rooms, living rooms, and bedrooms.

To survive the long, cold alpine winters, marmots hibernate for 6-8 or months out of the year. Each summer (and at their altitude, it’s a very brief summer), they must almost double their body weight. Much of their day is devoted to eating, and they have a varied diet. Marmots are usually vegetarians, consuming alpine grasses, leaves, and flowers, gut also eat fruits (when they can find them), grasshoppers, and even bird eggs. Full grown marmots weigh between 6 and 12 pounds (2.7-5.5 kilograms).

Marmots have several behaviors that set them apart from other mammals. To protect their young, marmot parents whistle, hoot, and squeak, and run back and forth to distract predators as their young flee to safety (another way they are considered altruistic). My favorite behavior is the Helicopter-Tail. When they sense danger, while fleeing, their tails spin around in a circular pattern- it sometimes appears like they’re getting an extra boost in speed with the propeller action of their tail. And while they’re running, they’re hooting and whistling, but honestly, in my head I hear Nya-aaa-aa, wooob-woob-woob-woob.

Pikas
Pikas are very close in appearance to large hamsters, but are actually more closely related to rabbits and hares. They’re often referred to as “rock rabbits.” They’re small animals, only about 6-8inches in length (160-220mm) and weigh about 6 ounces (170grams).

Unlike their marmot neighbors, pikas are awake and active over the winter months. To survive during the coldest months under the rocks and snow, pikas must gather enough food during their brief summers to last them through the winter. To do this, pikas devote a sizeable portion of every day to gathering food (grasses, leaves, flowers, thistles, etc.). The process for this is for the pika to run out in their talus field and gather mouthfuls of vegetation and pile it into tiny little hay bales to dry in the sun. Once the vegetation is dried, they bring it into their underground burrow for storage. Despite weighing only about 6 ounces themselves, they must gather in excess of 50 pounds of food to last the long alpine winter. It’s not uncommon for pikas to try to steal little hay bales from other neighboring pikas – when they’re caught, a loud argument usually ensues. These arguments are sometimes exploited by nearby predators.

Pikas live in small communities, but unlike their neighboring marmots, they tend to be solitary except for mating season. Pikas seem to have three speeds during the summer. The first is to perch themselves on a rock outcropping to survey their surroundings. They can be absolutely still during these times (presumably to prevent detection from raptors and other predators. The second is to move at blindingly fast speeds through the talus field, going out in search of and returning with mouthfuls of vegetation for processing and storage. because they blend in so well with their environment, they can be exceptionally tough to spot and track. Lastly, they disappear for long periods of time into their burrows in the talus, and may not emerge for minutes to hours later.

Pikas do share another trait with marmots. When they spot a predator or potential danger (or if you get too close to their little hay bales), they emit a surprisingly loud “EEENK.” They also keep themselves in harm’s way to alert their neighbors. It’s more common to hear pikas than see them.

Pikas have special adaptation to like at high altitude. They have very thick, dense fur means they stay warm in frigid temps and high winds, but it also means they can’t dissipate heat quickly or effectively, making them prone to overheating in warmer temps. About the only place not covered in thick fur is their eyes. Even their toes and the end of their nose is covered with fur. Their ears are short and round and lay almost flat against their skull, presenting the least area to the cold. When perched on a rock, they tuck their feet almost all the way under their bodies and bunch their shoulders around their short neck in an effort to conserve heat.

Both marmots and pikas are common (at least for now) in alpine regions of western North America. It’s easiest to spot marmot near roads and trails as the sun themselves on a warm rock or sit upright to survey their environment. Pikas are much more difficult to spot, in part because of their small size, their coloring, their speed, and their ability to look just like a rock when perched motionless on a rock outcropping. You’re much more likely to hear a pika than see one. Patience is rewarded, as both species are very curious and will check out visitors (from a distance) to their realm.

I find the best times to photograph marmots and pikas is summers, from dawn until mid morning. On very cold mornings (below freezing t mid 40’sF), marmots may be slow in getting out of their burrows and may wait for the sun to warm rocks. During the mid part of the day, marmots seems to nap, and may become active again in the late afternoons to close to sunset. Pikas seem to be busy most of the day, with three primary activities – perched on a rock, maniacally gathering, drying, and storing food, and hidden away in their burrows for long periods of time.

Because both species are smart and curious, sometimes the best photo strategies is to locate an area where you can hear marmot whistles and pika squeaks, and set you gear there quietly, and wait. Marmots are much easier to spot. They can approach quit closely at times when they don’t feel threatened. Pikas are much more difficult to spot. It’s not unusual to just see movement out of the corner of your eye as they run between the rocks. Spend some time and get to know your pika – they tend to have established routes and follow those routes most of the time. Instead of trying to track them with a long lens, pre-focus on a spot that you’ve observed them perch on, and when they resume their perch, hit the shutter. The more time you spend, the more familiar you’ll become with the routes and their habits. My favorite pika, Larry the Pika, has a routine that’s well known to me, and I can usually get fairly close and have memorized most of his favorite perches, allowing me to get set up and wait for my shots.

Since both species live anywhere from 8,000 to 14,000+ feet, dress appropriately. You may need to spend hours in the talus field waiting on your subjects. They have specialized fur to keep them warm and protected from the wind, and if all you have is a T-shirt and shorts, your photo safari will be over very quickly. And while you’re at altitude, wear a broad-brimmed hat and wear sunscreen. Your skin will thank you in the coming decades.

My usual set-up for capturing images is a DSLR and a telephoto lens, usually a 300mm f/2.8 with a variety of teleconverters. I use a tripod and gimbal head for practically every image I shoot. Without a tripod, I stand little chance of getting images of tiny little pikas that don’t look like a potato in a pile of rocks. I shoot close to wide open using a large aperture (f/2.8-5.6) to limit DOF and make the subject stand out from the background (in this case, similarly sized and colored rocks). There’s usually plenty of light, so low ISOs are the norm. Because of the plentiful sunlight, I sometimes add a polarizing filter to reduce glare and help prevent blown highlights from snow and light colored rocks – losing a couple of stops still gives me shutter speeds in the 1/1,000-2,000 range – plenty fast to freeze action.

Pikas, and marmots to a lesser extent, are considered at risk species due to climate change and global warming. They live on what is essentially a cold island. They are unable to migrate to different locations, as doing so would require them to cross long stretches of excessively hot ground. Their only alternative is to climb higher and higher up the mountain, and there’s only so much mountain to climb. Most pikas spend their entire lives in a half-mile radius. It’s estimated that pikas cannot survive in temps higher than 75F for more than a few hours.

Anecdotally, 8-9 years ago I rarely saw coyotes much above 12,000ft on Mt Evans, but now I see them regularly above 14,000ft, presumably pursuing their prey (marmots and pikas) as they continue to move up the mountain to escape climbing temperatures.

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