Pikas are small hamster-like animals, with short limbs, rounded ears, and short tails. The name pika (archaically spelled pica) is used for any member of the Ochotonidae, a family within the order of lagomorphs, which also includes the Leporidae (rabbits and hares). One genus, Ochotona, is recognised within the family, and it includes 30 species. Pikas are also called rock rabbits or coneys. It is also known as the "whistling hare" due to its high-pitched alarm call when diving into its burrow. The pika may look like a hamster, but is actually a cousin of the rabbit. The name "pika" appears to be derived from the Tungus "piika", or perhaps from the Russian "pikat", to squeak. In the United States the pronunciation of the name is usually altered from /pika/ to /'paɪ·ka/, probably due to the spelling.
In an article in the Journal of Biogeography, archeologist Donald Grayson warned that human activity and global climate change appeared to be pushing the American pika population to ever-higher elevations and thus possibly toward extinction. Grayson studied pika habitation over the past 40,000 years in the region between the Sierra Nevada (U.S.) and Rocky Mountains. An earlier Journal of Mammalogy article reached a similar conclusion.
These animals are herbivores, and feed on a wide variety of plant matter. Because of their native habitat, they primarily eat grasses, sedges, shrub twigs, moss, and lichen. As with other lagomorphs, pikas have gnawing incisors and no canines, although they have fewer premolars than rabbits, giving them a dental formula of:
Rock-dwelling pikas have small litters of less than five young, while the burrowing species tend to give birth to more young, and to breed more frequently, possibly due to a greater availability of resources in their native habitats. The young are born after a gestation period of between 25 and 30 days.
Pikas are diurnal or crepuscular, with higher altitude species generally being more active during the daytime. They show their peak activity before the winter season. Pikas do not hibernate, so they rely on collected hay for warm bedding and food. Pikas gather fresh grasses and lay them in stacks to dry. Once the grasses dry out, the pikas take this hay back to the burrows for storage. It is not uncommon for pikas to steal hay from others; the resulting disputes are usually exploited by neighboring predators like ferrets and large birds.
Eurasian pikas commonly live in family groups and share duties of gathering food and keeping watch. At least some species are territorial. North American pikas (O. princeps and O. collaris) are asocial, leading solitary lives outside the breeding season.
A model of wear in curved mammal teeth: controls on occlusal morphology and the evolution of hypsodonty in lagomorphs
Jan 01, 2007; Abstract.- Cheek teeth of some mammalian herbivores exhibit pronounced changes in occlusal size and shape through wear,...