CONTENTS

Living Organisms / Animalia / Craniata / Mammalia / Lagomorpha / Ochotonidae / Ochotona / Species

Ochotona princeps - American pika (Click photographs/illustrations for full picture & further details)

INDEX - INFORMATION AVAILABLE

Alternative Names (Synonyms)

Specific Ochotona princeps information

• North American pika (B285.w5i)
• Other common names for this pika include:
  • Rocky Mountain pika
  • Southern pika
  • Rock rabbit
  • Piping hare
  • Hay-maker
  • Mouse-hare
  • Whistling hare
  • Cony
  • (B430.w2)
• The American Pika has also been given the following specific names under five main groupings of populations in this species:
  • Northern Rockies: Ochotona cuppes, Ochotona goldmani, Ochotona levis, Ochotona lutescens, Ochotona obscura, Ochotona saturata.
  • Central Rockies: Ochotona figginsi, Ochotona clamosa, Ochotona fuscipes, Ochotona howelli, Ochotona lemhi, Ochotona uinta, Ochotona ventorum, Ochotona wasatchensis.
  • Southern Rockies: Ochotona saxatilis, Ochotona barnesi, Ochotona incana, Ochotona lasalensis, Ochotona moorei, Ochotona nevadensis, Ochotona nigrescens, Ochotona utahensis.
  • Sierra Nevada-Great Basin: Ochotona schisticeps, Ochotona albata, Ochotona cinnamomea, Ochotona muiri, Ochotona sheltoni, Ochotona tutelata.
  • Cascades: Ochotona taylori, Ochotona brooksi, Ochotona brunnescens, Ochotona fenisex, Ochotona fumosa, Ochotona jewetti, Ochotona littoralis, Ochotona minimus, Ochotona septentrionalis

(B607.w20)

• Previous names include Lepus (Lagomys) princeps, Lagomys minimus and Lagomys schisticeps. (J469.353.w1)

General pika information

• The name pika originated from the Tungus of Siberia who attempted to mimic the call "peeka" of the local pika species. (B285.w5g)
• The generic name of Ochotona is derived from the Mongolian name for pikas: "ogdoi". (B285.w5g)
• Mouse hares or conies are alternative names for pikas. (B147)
• "Pishchukha" is the Russian common name for all species of pika and some gerbils (Rhombomys opimus, Meriones tamareiscinus (Muridae - (Family)). (B605.3.w3)

Names for new-borns / juveniles

Names for males

Names for females

General Appearance

General pika information 

• Pikas are small, egg-shaped, rodent-like lagomorphs which weigh under 500 g. They have rounded, relatively large ears, short legs, and a very short tail which is hardly visible. (B285.w5g, B430.w2, J469.782.w1)

Specific Ochotona princeps information 

Newborn:

General pika information

• Newborn pikas are helpless and naked (B147, B287) or slightly furred. (B287)

Similar Species

This species of pika has a diploid chromosome number of 68 which along with morphological differences, helps differentiate it from other similar species of pikas including:

• Ochotona alpina - Alpine pika (B605.3.w3)
• Ochotona hyperborea - Northern pika
  • The Northern pika has a diploid chromosome number of 40. (B605.3.w3)
• Ochotona collaris - Collared pika
  • Has the same diploid chromosome number of 68 but is differentiated on the basis of craniometric data including the fact that the Collared pika's skull is relatively broad; (B605.3.w3)
  • The male Collared pika does not have the chattering long call that is characteristic of Ochotona princeps and some Asian pikas. (B605.3.w3)
  • Compared with Ochotona collaris - Collared pika , the underparts hava buffy wash, rather than being white, there is no greyish collar on the shoulders, and the length of the tympanic bulla is usually less than 25% of total skull length (usually greater than 27% in Ochotona collaris - Collared pika ). (J469.782.w1)

Sexual Dimorphism

• Male and female pikas are similar in size and can be difficult to tell apart from one another. (B147)

References

Species Authors & Referees

• See: DIRECTORY- Organisations working with Rabbits and their Relatives

• Rabbits, Hares and Pikas Status Survey and Conservation Action Plan
• See also: The Electronic Library- further reading for "Rabbits and their Relatives: Health & Management"

Husbandry Information

Notes

• --

Management Techniques

• Accommodation Design for Mammals
• Mammal Behavioural Requirements
• Food and Feeding for Mammals
• Mammal Handling & Movement
• Mammal Identification
• Preventative Medicine for Mammals
• Rearing of Mammals
• Reproductive Management of Mammals
• Management of Unwanted or Illegally Held Animals

Measurement & Weight

Notes

Specific Ochotona princeps information

• This species of pika is intermediate in size. (B605.3.w3)

LENGTH

Specific Ochotona princeps information

Adult: 162-216 mm (B430.w2, J469.782.w1)

Newborns: --

HEIGHT
Adults and sub-adults: --
Juveniles: --

WEIGHT
Adult: 

Specific Ochotona princeps information

• The weight of this species has been reported to be:
  • 113 to 180 grams. (B147)
  • 121 to 176 grams. (B430.w, J469.782.w1)

Newborns:

Specific Ochotona princeps information

Different studies have reported the following mean average weights for neonates of this species:

• 8.5 g (with a range of 4.1 to 12.5; sample size of 34). 
• 9.0 g (with a range of 8.0 to 10.23; sample size of 5).
• 12.4 g (with a sample size of 71).
• 11.5 g for males.
• 12.7 g for females.

(B287)

GROWTH RATE:

Specific Ochotona princeps information

Different studies have reported the following mean average weights for weanlings of this species:

• 52.24 g at 28 days (sample size of 28)
• 75 g at 6 weeks (standard deviation of 13.2; range of 50.9 to 103.2; sample size 37)
• 121.5 g for females at 59 days. 
• 132 g for males at 59 days.

(B287)

• By three months of age, young American pikas reach full adult weight. (B147, J469.782.w1)

Head and Neck

Notes

GENERAL HEAD STRUCTURE:
Adult:

General pika information

• In general, the head of pikas is blunt and short, and the skull is quite flattened rather than arched. There is also a constriction between the orbits. (B147)

Specific Ochotona princeps information

• The skull of the American pika is slightly rounded in profile and the region between the orbits is broad and flat. 
• The rostrum is slender.
• The nasals are widest anteriorly. 
  (B605.3.w3)

• General pika information: Pikas have small, rounded ears which are 12-36 mm in length. (B147; B285.w5g)

• General pika information: Pikas can completely close their nostrils. (B147)

• General pika information: These are longer in the rock dwelling pikas, such as this species, than in burrowing pikas. (B605.3.w3)

Newborn: --

DENTITION

• There are 26 teeth in total - two less than other lagomorphs who have one more upper molar on each side. (B285.w5a, B605.1.w1)
• The dental formula of pikas is 2/1 incisors, 0/0 canines, 3/2 premolars, and 2/3 molars. (B147, B605.1.w1)

Incisors

• Lagomorphs, including pikas, differ from rodents by having two pairs of upper incisors rather than just the one pair. The additional set of incisors are called peg teeth and are found directly behind the long pair in the upper jaw. (B147, B285.w5a, B605.1.w1)
• At birth, lagomorphs actually have three pairs of upper incisors, but they quickly lose the outer incisor on each side. (B147)
• The incisors are covered completely by enamel. (B147)
• The upper incisors' roots are found in the skull's premaxillary bones. However, the length of the lower incisors' roots varies. (B147)
  • [Note: lagomorphs have teeth which grow throughout their lives. For this reason the portion of the teeth which is not exposed (not above the gum line) is strictly speaking not a "root"; however, it is sometimes convenient to describe it as a root.]
• The first upper incisors have a cutting edge which is V-shaped. (B147)
• The peg teeth lack a cutting edge. (B147)

Molars

• Pikas have high crowned cheek teeth with no roots [the teeth grow continuously throughout life]. (B147)
• The lower tooth rows are closer together than the upper tooth rows. (B147)

EYES:

General pika information

• Pikas have eyes positioned to give a broad field of vision (B285.w5a)

Specific Ochotona princeps information

• Neonates are blind; the eyes open at eight to ten days. (B287)
• Eyes of American pikas open at about nine days old. (J469.782.w1)

Legs, Spine and Tracks

Notes

• Pikas have short legs. (B285.w5g)

Specific Ochotona princeps information

• The hindlimbs are just slightly longer than the forelimbs. (B147, B430.w2, B605.2.w2)
• They have five digits on each foot. (B147)
• The feet are heavily furred on the underside. (B147)
• In rock dwelling pikas, such as this species, the claws are more curved and less powerful than those of the burrowing pikas. (B605.3.w3)

Ochotona princeps specific information

• Hind foot 25 - 35 mm. (J469.782.w1)
• There are small, naked black pads at the ends of the toes, otherwise the soles of the feet are heavily furred. (J469.782.w1)

Tail

Notes

• The tail of pikas is virtually absent at a length of 5 mm (B285.w5g); it is not visible. (B147; B430.w2)

Skin / Coat / Pelage

Notes

Adult: 

• Fine, long, soft and dense coat with fur that covers the feet including the under surface. (B147, B285.w5g)
• Most pikas are lighter ventrally than dorsally. (B285.w5g)
• Most species have two moults per year with a brighter summer coat - often a yellowish red - and a greyer winter coat. (B147)

• Summer coat:
  • Dorsal surface: greyish to cinnamon-brown often enriched with a tawny or ochraceous colouring.
  • Ventral surface: whitish with a buffy wash.
• Winter coat:
  • Greyer and almost twice as long as the summer coat. 
  • The dense underfur is generally slate-grey or lead coloured.

(B605.3.w3, J469.782.w1)

Specific Ochotona princeps information

• Two annual moults, with the summer moult starting two weeks later in females than in males. (J469.782.w1)
• The vibrissae are 40 - 77 mm long. (J469.782.w1)

Adult Colour variations:

Specific Ochotona princeps information 

• There may be significant variability amongst the various forms.
• The coastal forms are usually darker than the subspecies found further inland except for those found on the dark lava beds.
• Melanistic forms may occur in this species.

(B605.3.w3)

Newborn/Juvenile:

General pika information

• Newborn pikas are hairless (B147, B287) or slightly furred. (B287)

Detailed Anatomy Notes
(Summary information provided for pertinent species-specific data cross-referenced in Wildpro)

Notes

• "In both sexes, the rectal canal and urogenital canal are separated by a septum terminating 2 to 3 mm from the single "pseudocloacal" opening, which must be everted to expose the penis (log and pointed) or the clitoris (broad, with a shallow groove." (J469.782.w1)

Specific Ochotona princeps information

• Three pairs of mammary glands (pectoral, abdominal and inguinal); these do not enlarge much during lactation. (J469.782.w1)

Female reproductive tract:

• Ochotona spp. general information: The uterus is duplex. The placenta is discoid, deciduate and hemochorial,with a mesometrial, superficial implantation. (B287)

• Testes:
  • The testes are intra-abdominal outside the breeding season. (B147, B287)
  • Ochotona princeps specific information: No obvious scrotum. (J469.782.w1)
• Penis:
  • Lagomorphs do not have a baculum. (B147)

Ochotona spp. general information

• Pikas have scent glands, as do all lagomorphs. (B285.w5a)

• There is an apocrine gland complex in the lower cheek from which scent marks are deposited. (J469.782.w1)

Natural Diet

Notes

NATURAL DIET:

General pika information

• Pikas are herbivorous - they eat grasses, flowering stalks, and leaves. Pikas have a preference for those plants highest in protein or other chemicals important to them. (B285.w5g)

• Pikas eat a range of vegetable matter: "in the summer and early autumn the animals gather grasses, sedges, weeds, and many of the large flowering and woody plants, sometimes climbing a few meters up in trees and out on limbs to cut twigs. The material is sometimes place in exposed locations for curing by the sun"; many populations create haystacks to store food for winter. (B147)

Specific Ochotona princeps information

• Studies of the American pika have demonstrated the following patterns: (B605.3.w3)
  • There are often differences in species composition of plants harvested, reflecting local variation in the composition of plant communities. (B605.3.w3)
  • At any one location, the pikas have a preference for certain plants and other plants are not harvested at all. (B605.3.w3)
  • These plants which are preferred by the pikas are often harvested in a precise sequence that usually corresponds to their seasonal phenology. (B605.3.w3)
• Preferred plants of the American pika have a markedly higher water, protein, calorie and lipid content than other plants. They ignore some plants due to the presence of toxic chemicals. (B605.3.w3, J469.782.w1)
• Cushion plants are thought to be an important winter food (in addition to food stored in haypiles); lichens may also be importent in the winter diet. (J469.782.w1)
• Amount eaten:

  • Daily energy intake for a 171 g non-pregnant, non-lactating adult American pika is estimated at 54.8 kcal, with an assimilation of about 68%. This is equivalent to filling the stomach nine times per 24 hours. (J469.782.w1)

  • A pregnant or lactating female increases her food intake and possibly also her intake of caecotrophs. (J469.782.w1)

Hibernation / Aestivation

Notes

• Pikas, including this species do not hibernate. (B147, B285.w5g, B430.w2, B605.3.w3, J469.782.w1)

Haematology / Biochemistry

Notes

HAEMATOLOGY: --

BIOCHEMISTRY: --

Detailed Physiology Notes
(Summary information provided for pertinent species-specific data cross-referenced in WILDPro)

Notes

METABOLISM (TEMPERATURE):

General pika information 

• Pikas have a high body temperature. (B285.w5g)

Specific Ochotona princeps information 

• Body temperature is about 40.1 °C, with an upper lethal temperature of 43.1 °C and a lower critical temperature of 21 °C. (J469.782.w1)

• They have a relatively high basal metabolic rate and low thermal conductance. (J469.782.w1)

• Thermoregulation in response to high ambient temperatures is mainly behavioural, with pikas being fairly inactive on warm days. (J469.782.w1)

• Even brief exposures to relatively moderate ambient temperatures (25.5 - 29.4 °C) can cause hyperthermia and death. (J469.782.w1)

• Daily energy intake for a 171 g non-pregnant, non-lactating adult American pika is estimated at 54.8 kcal, with an assimilation of about 68%. (J469.782.w1)

RESPIRATORY SYSTEM (RESPIRATION): --

CIRCULATORY SYSTEM (PULSE/HEART RATE): --

GASTROINTESTINAL SYSTEM (FAECES AND GUT MOTILITY):

General pika information

• Jaw motion: Pikas have a vertical or transverse jaw motion. (B147); pikas use a side-to-side jaw motion. (B285.w5g)
• Coprophagy: Pikas produce two types of faeces, hard faeces like pepper seeds - small green spherical pellets - which are passed during the day; and soft faeces, sticky and dark green/black, passed at night. Faeces of the latter type have high a energy value and B vitamin levels, and are re-ingested. This behaviour, known as coprophagy, may have a similar function to the ruminant behaviour of chewing the cud. (B147, B285.w5a)

• Unlike most lagomorphs, American pikas can produce caecotrophs throughout the day and may either consume them directly as they are produced or store them and consume them later. Caecotrophs are higher in both energy and protein than is plant material stored in haypiles. (J469.782.w1)

URINARY SYSTEM (URINE): --

CHROMOSOMES:

Specific Ochotona princeps information

• Diploid chromosome number is 68. 
  • This is the same as Ochotona collaris - Collared pika and Ochotona pusilla - Steppe pika.
  • Whereas the diploid chromosome number in the similar species of Ochotona alpina - Alpine pika and Ochotona hyperborea - Northern pika is 42 and 40 respectively. 

  (B605.3.w3; B607.w20, J469.782.w1)

MUSCULO-SKELETAL SYSTEM: --

SPECIAL SENSES AND VOCALISATIONS:

Vocalisations:

• Pikas are known to be more vocal than other lagomorphs. (B285.w5a)

Specific Ochotona princeps information 

• The American pika has two characteristic and frequently used vocalisations:

Short call: 

• This is uniform within populations (although it is possible to recognise individuals based on their distinctive calls) but varies geographically. (B605.3.w3, J469.782.w1)
• This call is used by the pika as either an alarm call to warn of predators and it is used to discourage other pikas from intruding on its territory (it is uttered when the pika is about to leave its territory to forage and then again upon return (B430.w2)). (B147; B430.w2; B605.3.w3, J469.782.w1)
  • In one study, a resident pika was killed by a weasel and immediately all the resident pikas in the vicinity uttered the consecutive short calls that are used when they are alarmed by predators; the only pika in the area that didn't use the call was an unrelated immigrant pika that had only just come into the area. (B285.w5h)
• Alarm calls are usually repetitive short calls. (B605.3.w3)
• Short calls are used by both sexes of all ages. (B605.3.w3)
• This short, sharp call is reported to vary geographically and also individually. (B147)

Long call:

• This call is used by adult males mainly in the breeding season. (B147; B430.w2; B605.3.w3, J469.782.w1)
• Females may also use this vocalisation with an apparently territorial role. (B147)
• Long calls are used most often in the breeding season; they are also used by both sexes in autumn. (J469.782.w1)

Additional calls

• There is also a third vocalisation which is a submissive squeak uttered by juvenile pikas when chased by adults. (B147)
• Nursing chirps may be given from day one and twitters from day nine; "the twitter maintained its infant quality, except in that it became louder and more like the tooth chatter with age." This twitter was used in various contexts. Adult vocalisations of the alarm call and "raspy wail" started at 12 days old. (J334.32.w1)

Scent glands:

General pika information

• Pikas have scent glands, as do all lagomorphs. (B285.w5a)
• Both sexes use scent marking. (B430.w2)
• They communicate by depositing scent onto rocks from (in North American species) "the enlarged apocrine gland complex found on their cheeks". It is possible for pikas to discriminate among individuals by the odours from these scent marks.  (B605.3.w3)
• The two functions of this behaviour are:
  • territory maintenance and possibly advertisement.
  • sexual advertisement leading on to mating.
    (B605.3.w3)
• Ochotona princeps specific information: 
  • Scent marks are deposited from the apocrine gland complex in the lower cheek by rubbing onto rocks. This is carried out by both sexes and is used to distinguish individuals. (J469.782.w1)

• Scent marks are deposited from the apocrine gland complex in the lower cheek by rubbing onto rocks. This is carried out by both sexes and is used to distinguish individuals. (J469.782.w1)

Feeding Behaviour

Notes

• Pikas are unable to grasp plants with their forepaws; they eat with a side-to-side jaw motion and carry vegetation in their mouths. (B285.w5g)

Haying and foraging 

• In spring, summer and/or autumn (fall) (depending on species/location) many pika species spend much time "haying" - harvesting mouthfuls of vegetation which are carried back to the den for storage. They build up these stores, resembling piles of hay, and use them for consumption during periods of sparse vegetation, often over-harvesting so that it is a rare occurrence for them to run out of food. (B285.w5g, B605.3.w3) 
• Pika species living in areas where winter snow is common may also make tunnels in the snow to reach and harvest any nearby vegetation. (B285.w5g)
• Some species continue to forage throughout winter rather than haying, because snows are uncommon. (B285.w5g)
• Even at a fairly low population density of ten to twelve pikas per hectare, vegetation storage by pikas may be up to 30 kg per hectare. (B605.3.w3)

Specific Ochotona princeps information

• The American pika uses two forms of feeding - directly eating and making haypiles for later consumption. (J469.782.w1)
• Over 30% of this species' active time is devoted to haying. (B285.w5g)
• The size of haypiles is influenced by the following factors:
  • sex - males have larger haypiles;
  • age - adults have larger haypiles;
  • amount of forage available from meadows close by;
  • distance that vegetation has to be transported.

  (J469.782.w1)

• Most piles of hay are built close to the talus-meadow interface and these sites seem to be traditional. (J469.782.w1)
• Haying starts after the breeding season and males start making haypiles earlier than do females. (J469.782.w1)
• During the summer, pikas can be seen making trips from the talus to nearby meadows to forage or gather hay. This hay is then taken back to the talus and stored in haypiles to act as winter stores of food. The hay is reportedly not cured or dried on the talus before storage. (B430.w2)
• In Washington, this species of pika has been observed devoting more energy to gathering hay as the season advanced. (B147)
  • "Fresh leaves would be laid out daily on top of the conical heap and partly cured by the sun until the mass rose to a height of 600 mm" (B147)
  • One pika was reported to bring in fifteen loads of hay during the period of 06.45 to 07.45 hours. (B147)
  • The researchers found that most of the haystacks in the area were out in the open and were not taken under cover for the winter. (B147)
  • The pikas were reported to place many small stores of just one or two mouthfuls in scattered crevices among the rocks. However, the main effort of each animal was concentrated on one large haystack. (B147)
• In southwestern Alberta, the haying season is reported to extend from June to October with the maximum intensity of activity occurring in August. Most pikas make one or two large haypiles beneath large rocks; however, a few pikas make five or six small piles. The process of curing was not observed. The weight of food in each hay stack has been reported to reach 400 to 6000 grams by September. However, it is thought that pikas are likely to forage year-round because very few animals gathered enough food material to last through the winter. Also, a few individuals have been seen to habitually attempt to steal food from their neighbours' haypiles. (B147)
• Ochotona princeps has been reported to venture, on average, only 2.19 metres in its home range when it was just grazing but 7.49 metres when it was gathering material for haying. (B147)
• Haypiles may be under a boulder, or exposed. (J469.782.w1)
• Short alpine grasses are generally eaten, which tall grasses and forbes are usually taken to a haypile. (J469.782.w1)

Parental Behaviour

Notes

• "Although males do not contribute directly to the raising of their offspring, they still primarily associate with a single neighbouring female". (B285.w5h)
• The female remains away from her young for long times, visiting to nurse the young once per two hours, remaining only 10 minutes. (J469.782.w1)
  • Captive data showed visits to the nest about twice an hour during the first week. (J334.32.w1)
  • Nursing visits occurred only every two hours, with nursing bouts lasting 10.7 minutes on average. While the young were nursing, the doe vigorously licked them: "during the first week, females averaged 33 s of licking for every 5.6 min of nursing." (J334.32.w1)
  • Other visits to the nest were short, involving sniffing the young and nest-maintenance activities, with about 1.5 minutes per hour spent on nest maintenance. Materials surrounding the nest were used to carefully cover the young; this generally hid the young as well as discouraging them from wandering out of the nest. (J334.32.w1)
  • Neonates which wander out of the nest are not retrieved by the mother. (J334.32.w1)
  • Maternal visits to the nest decreased with time (0.89 +/- 0.61 visits per hour in the second week), so that it was near zero by the third and fourth week post-partum ( 0.16 +/- 0.20 visits per hour in the third week, 0.07 +/- 0.08 in the fourth week). As female-initiated nursing (by the female returning to the nest) decreased, the young started to attempt to nurse (nuzzling the female's flanks and belly), but these attempts were usually unsuccessful. Occasional success could extend the period of nursing to the sixth week. (J334.32.w1)

Social Behaviour / Territoriality / Predation / Learning

Notes

Social

General pika information

• The rock dwelling pikas are often relatively asocial.  (B605.3.w3)

• It is rare that they interact and usually it is to repel an intruder if they do so. (B285.w5g)

• Even in a pair of pikas which are contributing to a shared hay pile, they spend a large part of the day apart. (B285.w5g)

Territoriality

General pika information

• Pikas are highly territorial lagomorphs; both sexes use scent marking and vocalisations to maintain territories. (B605.1.w1)

• The rock- dwelling pikas have large territories defended by the individual (in North American species). (B285.w5g, B605.3.w3)

• The population density is low, at 5-25 per acre, and reasonably stable over a period of time. (B285.w5g, B605.3.w3)

  • Population densities of pikas in rocky areas do not usually reach more than 20 per hectare. (B147)

Specific Ochotona princeps information

• Adults are individually territorial and the sex ratio of adults has been found to be close to 1:1. (B605.3.w3)
• Male and female average territory sizes are similar. (B605.3.w3)
• Territory sizes vary seasonally, being substantially larger in early rather than in late summer. (B605.3.w3)
• "Size of territories averages about 55% of home range size." (B605.3.w3)
• Defence of territories is primarily by aggression with an American pika chasing and fighting conspecifics. Displays of aggression don't occur very often, "generally less than one act for every 10 hours" and usually occur between same sex animals. The highest frequency of aggression occurs when unfamiliar animals come into contact, for example an immigrant and a resident. While individuals frequently intrude on their neighbours' territories, usually they do this only when the resident is inactive. (B605.3.w3, J469.782.w1)
  • There may be a hierarchy, with some individuals being dominant over, and aggressive towards, other individuals. (J469.782.w1)
• Juveniles:
  • Young American pikas are born into the relatively static and permanent social organisation of territory holders. The chance of a young pika living to adult age is dependent on it discovering a vacant territory to occupy; this can be quite unpredictable and infrequent in time and space. (B605.3.w3, J469.782.w1)
  • If juveniles do disperse they are confronted with high rates of aggression by adults unfamiliar to them, therefore most remain on their natal range or in an area adjoining it (philopatry), with only about 25% attempting dispersal.. (B605.3.w3, J469.782.w1); 
  • In one study there was no sex bias to dispersal, although in other studies, females were more likely than were males to disperse more than 100 m. (J469.782.w1)
  • On their natal range, juveniles remain in areas as far as possible from siblings, dam and possible father, and generally are active while the adults are inactive. (J469.782.w1)
• This philopatric settlement pattern has resulted in a highly inbred population and significantly low levels of genetic heterozygosity within these populations. (B605.3.w3)
• There appears to be a non random spacing of males and females on the talus: adjacent home ranges are often inhabited by opposite sex individuals and if a territory becomes vacant it tends to be re-occupied by another pika of the same sex as the previous inhabitant. (B147; B285.w5h; B430.w2, B605.3.w3, J469.782.w1)
• "Overlap of home ranges is greater and nearest-neighbor distances are less between paired adults than between nearest-neighbors of the opposite sex". (B605.3.w3)
• Population size is notably stable from year to year. (B605.3.w3)
• The American pikas have on average a population density of six to ten pikas per hectare. (B605.3.w3)
• The average population density of this species is reported to be around 15/ha. (B147)
• In Alberta, the population density of this species has been reported to be 4-22/ha. (B147)
• When the young are weaned they they move out on their own and compete for territory. However, one study found that most young pikas stay in their natal home range for the summer and eventually settle within fifty metres of the centre of this area. (B147; B285.w5h)
• Adult male and female pikas of this species live separately for the majority of the year. Territoriality is highly developed in this species. Each adult pika will usually have a home range that includes a patch of talus with an adjacent area of vegetation and much of this range will be vigorously defended. (B147)
  • Females are apparently more aggressive towards neighbouring females than they are towards neighbouring males. Male residents are rarely seen exhibiting aggression towards each other because they tend to avoid one another by using vocalisations and scentmarking. However, they will vigorously attack unfamiliar males that are new to the area. Adults will treat their weaned offspring in a similar fashion as neighbours of the opposite sex; the juveniles will encounter some aggression but also frequent expressions of social tolerance. (B285.w5h)
• One study of this species reported that an individual pika will defend its territory for most of the year against all other pikas regardless of sex. However, during the spring breeding season, male pikas usually increase the size of their territories to include the territory of at least one female, and then for a while, the pair will defend a joint territory against other pikas. As the summer haying season progresses, the female pikas becomes more aggressive towards the male pikas resulting in the males contracting their ranges and then eventually all the pikas end up occupying individual territories again. Meanwhile, young pikas are weaned and expelled from their natal home range by their mothers. The juveniles then disperse among the local population and try to find somewhere to set up their own territories. Territoriality of this species is reported to reach peak intensity at the height of the pikas' haying season with the defended areas centring on the main food stores of individuals. The average distance between hay stacks is around 25 to 30 metres. There are constant chases and the pikas examined in the field frequently show evidence of severe wounds. (B147)
• Individuals rub their cheek glands against rocks to scent-mark their territories. (B147; B430.w2, J469.782.w1)
• Male and female territories are of a similar size. (B430.w2)
• In central Colorado, individual home ranges were reported to cover 416 to 3036 square metres, of which 319 to 1365 square metres composed actual territories. (B147)
• The average population density of this species is reported to be around 15/ha. (B147)
• In Alberta, the population density of this species has been reported to be 4-22/ha. (B147)
• In general, the rock dwelling pikas such as the American pika, have large territories defended by the individual or defended in pairs. The population density is therefore low, at 5-25 per acre, and reasonably stable over a period of time. (B285.w5g, B605.3.w3) 
  • It is rare that they interact and usually it is to repel an intruder if they do so. Even in a pair of pikas which are contributing to a shared hay pile, they spend a large part of the day apart. (B285.w5g)

Predation

Specific Ochotona princeps information

• Potential predators of this species include:
  • Longtail weasels Mustela frenata (Mustela - (Genus))
    • the smaller weasels are thought to be the most successful predators of this species because they can follow the pikas into their shelters between the rocks. (B430.w2)
  • Martens (Martes americana - American marten (Martes - (Genus)))
  • Canis latrans - Coyote
  • Ermine (Mustela erminea - Stoat)
  (B430.w2)

Sexual Behaviour

Notes

• In general, it appears that pikas are monogamous. (B285.w5g, B605.3.w3)
• Ecological constraints have apparently led to rock-dwelling pikas, including this species, having a monogamous mating system. For polygyny to occur, males must either be able to: 
  • directly defend several females (not possible because the female pikas are dispersed and their mutual antagonism keeps them apart) (resource-defence polygyny). (B285.w5h)
  • monopolise sufficient resources to attract quite a few females (not possible because of "the essentially linear reach of vegetation at the base of the talus") (female-defence polygyny). (B285.w5h)

Specific Ochotona princeps information

• Social cohesion in American pikas is maintained among nearest-neighbour pikas of the opposite sex (i.e. pair-mates) by social tolerance and by vocal duets of short calls. The paired spatial configuration, its persistence in time and the interplay of aggression and social tolerance has lead to the mating system being classified as facultatively monogamous. (B605.3.w3, J469.782.w1)
  • Where more than one mate is available, females may show mate choice. (J469.782.w1)

Activity Patterns, Self-grooming and Navigation

Notes

ACTIVITY PATTERNS:

Specific Ochotona princeps information

• The main activities seen are surveillance or sitting on a rock (up to 50% of the surface-active time), feeding or haying, vocalising and activities related to maintaining or establishing a territory (vocalising, cheek rubbing, aggression and social tolerance). (J469.782.w1)
• This species of pika is often seen sitting still on the top of sloping rocks surveying its territory. (B430.w2)
• Over 30% of this species' active time is devoted to haying. (B285.w5g)
• As a behavioural means of thermoregulation, these pikas are fairly inactive on warmer days and, at lower altitudes, they avoid activity in the middle of the day. (J469.782.w1)
• General pika information: Pikas are agile and lively (B285.w5g)

• Pikas are agile and lively (B285.w5g)

SELF-GROOMING: --

CIRCADIAN RHYTHM:

Specific Ochotona princeps information

• This species is diurnal. (B430.w2)
• There has been a report of this species dying after a thirty minute exposure to 25 ºC / 77º F. (B285.w5g) 
• Populations of this species which live at high altitudes may be active all day, whereas those that are found at warmer, lower, altitudes, emerge only at dawn and dusk. (B285.w5g)
• General pika information:
  • Pikas are well-adapted to the cold and sensitive to even moderately warm conditions, therefore they tend to be active only during the cooler parts of the day. (B285.w5g)
  • Pikas may be active at all hours, in particular, early morning and evenings. It seems that they are less active on sunny days compared with cloudy days. (B147)
  • Pikas which live at high altitudes may be active all day, whereas pikas at warmer, lower altitudes emerge only in the morning and evening. (B285.w5g)

• Pikas are well-adapted to the cold and sensitive to even moderately warm conditions, therefore they tend to be active only during the cooler parts of the day. (B285.w5g)
• Pikas may be active at all hours, in particular, early morning and evenings. It seems that they are less active on sunny days compared with cloudy days. (B147)
• Pikas which live at high altitudes may be active all day, whereas pikas at warmer, lower altitudes emerge only in the morning and evening. (B285.w5g)

SPEED OF MOVEMENT: --

NAVIGATION: --

General Habitat Type

Notes

• Most pikas live in remote high mountains and wild country and are well adapted to the cold.
  Pikas have become well adapted to living in rocky steppe and alpine habitats. (B285.w5g, B605.3.w3)

Specific Ochotona princeps informationn

• The American pika is found in a talus habitat which is frequently patchily distributed, leading to island-like population structures. (B605.3.w3)
• "Talus or piles of broken rock fringed by suitable vegetation." Usually uses rocks 0.2 - 1.0 m diameter, but with haypiles under larger boulders, and with large, prominent rocks used for sitting on (J469.782.w1)
• Found at sea level to 3,000 m in the northern part of its range, but further south the lower elevations used become higher due to the inability to tolerate high daytime temperatures - in the south of its range it is generally seen only above 2,500 m. (J469.782.w1)

Nests / Burrows / Shelters

Notes

• The American pika is a rock dwelling pika and its habitat is quite specific to piles of broken rock or talus fringed by suitable vegetation. (B147, B430.w2, B605.3.w3)
• Maternal nests: Prior to parturition the female forms a nest in the substrate, but without lining it with hair (unlike rabbits and hares). (J334.32.w1)
• These pikas have been observed to use burrows. When kept in large (one acre) enclosures, with natural substrate, these pikas, dug burrows near the buried dens provided and along the borders of the enclosures. Excavated areas, 8 - 13 cm deep, by the buried dens were used as additional hiding places and for storage of vegetation. Two individuals occupied burrows near dens for a period of two months, and other pikas lived in burrows near the fence; many of these burrows led to cavities where large clods of earth had been replaced after the fence was buried. It was noted that the pikas, while digging, would remove rocks (gravel) by carrying them in their teeth and placing them in piles either on top of the den or by the sides of the cages (and in once case in a feeder). Additionally, the pikas were noted to dig surface depressions, ranging from barely noticeable to 6 x 10 x 24 cm; they defecated in these depressions. (J332.53.w2)

Distribution and Movement (Migration etc.)

Notes

Specific Ochotona princeps information

This species is distributed discontinuously in mountainous regions (including Rocky, Cascade and Sierra Nevada Mountains) throughout western North America:

• Canada: 

  • British Columbia

  • Alberta.

• United States: 

  • Washington

  • Oregon 

  • Nevada

  • California

  • Idaho

  • Montana

  • Wyoming

  • Utah

  • Colorado 

  • New Mexico.

(B285.w5i, B605.3.w3, B607.w20, J469.782.w1)

• Of the 30 species of pika in the world, only two are found in North America - this species and Ochotona collaris - Collared pika; the rest are found across Asia. (B285.w5a)

Elevations: 

• In the southern part of its range, Ochotona princeps is usually only found at elevations higher than 2500 metres. (B430.w2, B605.3.w3)

• However, towards the northern part of its range, this pika may be found at lower elevations (from sea level to 3000 metres). (B430.w2, B605.3.w3)

Conservation Status

Notes

WILD POPULATION - IMPORTANCE:

General pika information

In general, pikas are important for the following reasons:

• They act as prey for many birds and mammals. 
• Haypiles created by pikas may provide winter food for domestic cows and horses and also native species such as ungulates or smaller herbivores.
  (B605.3.w3)

GENERAL LEGISLATION:

• "Currently no species or forms of Ochotona are treated on any national list of endangered or threatened wildlife." (B605.3.w3)

CITES LISTING:

• There are currently no Ochotona species CITES-listed. (W354.April08.w1)

RED-DATA LIST STATUS:

Specific Ochotona princeps information

• IUCN - Lower risk/least concern. (W2.Apr08.w59)
• IUCN - Vulnerable subspecies: 
  • goldmani
  • lasalensis
  • nevadensis
  • nigrescens
  • obscura
  • sheltoni
  • tutelata

(W2.Apr08.w59)

THREATS:

Specific Ochotona princeps information

• There seems to be no current threats to the abundance or distribution of most forms of this species of pika. "However, some isolated populations in the Great Basin of the United States, including one from a subspecies type locality (O. p. tutelata), have disappeared in recent years." (B605.3.w3)
• Ochotona princeps goldmani: south central Idaho, the population of this pika is estimated at less than 1000 mature individuals. (B147)
• Ochotona princeps lasalensis: southeastern Utah, the population of this pika is thought to be less than 1000. (B147)
• Ochotona princeps nevadensis: northeastern Nevada, the population of this pika is estimated at less than 1000 and it is thought that it may have lost all or most of its genetic variability. (B147)
• Ochotona princeps nigrescens: Jemez Mountains of north-central New Mexico, the population of this pika is thought to be less than 1000. (B147)
• Ochotona princeps obscura: Big Horn Mountains of north-central Wyoming, the habitat of this pika is expected to decline. (B147)
• Ochotona princeps sheltoni, White Mountains of southwestern Nevada, the population of this pika is thought to be less than 1000. (B147)
• Ochotona princeps tutelata, central Nevada, the habitat of this pika is expected to decline. (B147)
• A recent electrophoretic survey demonstrated that O. p. nevadensis might have lost most, or possibly all, of its genetic variability. (B605.3.w3)
• In general, the status of many species of pika is hard to assess because they inhabit such remote areas. (B285.w5g)
• Many species of pika inhabit very restricted ranges and so may be threatened by human environmental disruption. (B147)

PEST STATUS / PEST POPULATIONS:

General pika information

• Due to their remote habitat, most pikas "rarely come into conflict with human economic activity." (B147)

CAPTIVE POPULATIONS: --

TRADE AND USE: --