Geologic Reference Cards With a Purpose
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American & Collared Pika

If you’ve spent time in Rocky Mountain high country, chances are good you’ve either heard or seen an American pika (Ochotona princeps). Originally from the central Asian steppes, these potato-sized mammals migrated across the Bering Land Bridge and have been calling North America home for the past several million years. Nowadays, American/Collared pikas can be found throughout the Rocky Mountains between northern New Mexico and central British Columbia. Populations are also present in the Great Basin and from California’s Sierra Nevada north to the Cascade Range in Oregon and Washington.

American/Collared pikas are often easiest to spot in talus – fields and slopes of broken rock – above ~8,000’ in elevation. Keep your eyes open for grayish-brown critters with large ears and no tails. They’ll often be scurrying between the rocks or taking in the view from a particularly prominent perch. Even if you don’t spot one, you’ll likely hear them: they have a distinctive, squeaky  Eep! call that’s particularly loud for such a tiny animal!

(Colorado Pika Project)

For Additional Info:

Not to be confused with Pica or Pikachu.
For other uses, see Pika (disambiguation).
Pika[2]

Temporal range: Miocene–Holocene, 16.4–0 Ma[1] 
American pika (Ochotona princeps)
Scientific classificationEdit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Lagomorpha
Family: Ochotonidae
Thomas, 1897
Genus: Ochotona
Link, 1795
Type species
Ochotona daurica

Link, 1795
(Lepus dauuricus Pallas, 1776)
Species
See text

A pika is a small, mountain-dwelling mammal native to Asia and North America. With short limbs, a very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but with short, rounded ears.[3] The large-eared pika of the Himalayas and nearby mountains lives at elevations of more than 6,000 m (20,000 ft).

Pikas prefer rocky slopes and graze on a range of plants, primarily grasses, flowers, and young stems. In the autumn they pull hay, soft twigs, and other stores of food into their burrows to eat during the long, cold winter.[4] The pika is also known as the whistling hare because of its high-pitched alarm call when diving into its burrow.

The name “pika” appears to be derived from the Tungus pika,[5] and the scientific name Ochotona is derived from the Mongolian word ogotno, оготно, which means pika.[6] It is used for any member of the Ochotonidae (/ɒkətoʊnɪdeɪ/),[7] a family within the order of lagomorphs which also includes the Leporidae (rabbits and hares). Only one genus, Ochotona[7] (/ɒkəˈtoʊnə/ or /ɒtʃəˈtoʊnə/), is extant within the family, covering 37 species, though many fossil genera are known. Another species, the Sardinian pika, belonging to the separate genus Prolagus, has become extinct within the last 2000 years owing to human activity.

The two species found in North America are the American pika, found primarily in the mountains of the western United States and far southwestern Canada, and the collared pika of northern British Columbia, the Yukon, western Northwest Territories and Alaska.

Habitat

Collared pika on Hatcher Pass, Alaska

Pikas are native to cold climates in Asia and North America. Most species live on rocky mountainsides, where numerous crevices are available for their shelter, although some pikas also construct crude burrows. A few burrowing species are native to open steppe land. In the mountains of Eurasia, pikas often share their burrows with snowfinches, which build their nests there.[8] Changing temperatures have forced some pika populations to restrict their ranges to even higher elevations.[9]

Characteristics

Ochotona sp. fossils[further explanation needed]

Pikas are small mammals, with short limbs and rounded ears. They are about 15 to 23 cm (6 to 9 in) in body length and weigh between 120 and 350 g (4 and 12+1⁄2 oz), depending on species. Like rabbits, after eating they initially produce soft green feces, which they eat again to take in further nutrition before producing the final solid fecal pellets. Collared pikas have been known to store dead birds in their burrows for food during winter and eat the feces of other animals.[10]

These animals are herbivores and feed on a wide variety of plant matter, including forbs, grasses, sedges, shrub twigs, moss and lichens. As with other lagomorphs, pikas have gnawing incisors and no canines, although they have fewer molars than rabbits; they have a dental formula of: 2.0.3.21.0.2.3. Another similarity that pikas share with other lagomorphs is that the bottom of their paws are covered with fur and therefore lack paw pads.[11]

Rock-dwelling pikas have small litters of fewer than five young, whilst the burrowing species tend to give birth to more young and to breed more frequently, possibly owing to a greater availability of resources in their native habitats. The young are born after a gestation period of between 25 and 30 days.[8]

Activity

Pikas are active during daylight (diurnal) or twilight hours (crepuscular), with higher-elevation species generally being more active during the daytime. They show their peak activity just before the winter season. Pikas do not hibernate so they generally spend time during the summer collecting and storing food for the winter. Each rock-dwelling pika stores its own “haypile” of dried vegetation, whilst burrowing species often share food stores with their burrow mates. Haying behavior is more prominent at higher elevations. Many of the vocalizations and social behaviors that pikas exhibit are related to haypile defense.

The impact of human activity on the tundra ecosystems where pikas live has been recorded dating back to the 1970s.[12] Rather than hibernate during winter, pikas forage for grasses and other forms of plant matter and stash these findings in protected dens in a process called “haying” which they sustain themselves with during winter seasons.[13] Sometimes pikas think that humans are predators, so they sometimes respond to humans as they do to other species that may actually be preying on the pikas. Such interactions with humans have been linked to pikas having reduced amounts of foraging time, consequentially limiting the amount of food they can stockpile for winter months.[14] Pikas prefer foraging in temperatures below 25 °C (77 °F), so they generally spend their time in shaded regions and out of direct sunlight when temperatures are high.[14] A link has also been found between temperature increases and lost foraging time, where for every increase of 1°C to the ambient temperature in alpine landscapes home to pikas those pikas lose 3% of their foraging time.[14]

Eurasian pikas commonly live in family groups and share duties of gathering food and keeping watch. Some species are territorial. North American pikas (O. princeps and O. collaris) are asocial, leading solitary lives outside the breeding season.[15]

Vegetation pile drying on rocks for subsequent storage, Little Cottonwood Canyon, Utah
American pika with mouthful of dried grass, Sequoia National Park, California

Dialects

Pikas have distinct calls, which vary in duration. The call can be short and quick, a little longer and more drawn out or long songs. The short calls are an example of geographic variation. The pikas determine the appropriate time to make short calls by listening for cues for sound localization.[16] The calls are used for individual recognition, predator warning signals, territory defense, or as a way to attract the opposite sex.[17] There are also different calls depending on the season. In the spring the songs become more frequent during the breeding season. In late summer the vocalizations become short calls. Through various studies, the acoustic characteristics of the vocalizations can be a useful taxonomic tool.[18]

Lifespan

The average lifespan of pikas in the wild is roughly seven years. A pika’s age may be determined by the number of adhesion lines on the periosteal bone on the lower jaw. The lifespan does not differ between the sexes.[19]

( https://en.wikipedia.org/wiki/Pika )

The Genius of the Pika

Well, the genius of the pika is that it turns the plants’ own defenses against them. Plants don’t like having their leafy parts eaten, because it reduces their ability to photosynthesize, so they have evolved countless ways of discouraging predation by herbivores, and the herbivores have co-evolved countless ways overcoming those defenses. One of the main ways plants make themselves undesirable or inedible is to produce toxic compounds, the most common of which are tannins and other phenols, which make them unpleasant to eat and difficult or impossible to digest. Some animals have evolved a resistance to these compounds, such as enzymes or gut bacteria that help break them down, but the pika does something else entirely.

In the summer months, the pika will gorge itself on plants that are low in phenolic compounds, as they are readily digestible. But it will select a range of plants to store for later that are higher in phenols. The pika won’t eat these plants immediately, it caches them for the winter. The reason for this is that phenolic compounds don’t just discourage predation, they also act as a preservative. Plants higher in phenols don’t decompose as quickly as the more immediately-desirable kinds. What’s more, as they age, the toxins break down as well, rendering them edible and what’s more, more nutritious than plants stored for the same time that were low in phenols to begin with.

Turns out pikas can tell the difference between plants with high and low phenol levels; even when they are presented with a choice of plants which are the same species but individually have differing phenol levels, pikas selected the lower level plants for immediate consumption. This is a fantastic strategy for a creature like the pika. They eat the most nutritious and digestible food first, then move on to the other plants as they become more consumable over time, while at the same time ensuring they have supply of food throughout the whole winter and that it will remain nutritious and safe to eat (due to anti-bacterial and anti-fungal action of the phenols). The pika has completely co-opted the plant strategy for it’s own benefit.

(The Olive Tree)