View source for Pika

{{Short description|Genus of mountain-dwelling mammal}}
{{Other uses}}
{{Automatic taxobox
| name = Pika<ref name=MSW>{{MSW3 Hoffmann|pages=185–193}}</ref>
| fossil_range = [[Miocene]]–[[Holocene]], {{Fossil range|16.4|0|ref=<ref name="Ge13" />}}
| image = American pika (ochotona princeps) with a mouthful of flowers.jpg
| image_caption = [[American pika]] (''Ochotona princeps'')
| parent_authority = [[Oldfield Thomas|Thomas]], 1897
| taxon = Ochotona
| authority = [[Heinrich Friedrich Link|Link]], 1795
| type_species = ''[[Daurian pika|Ochotona daurica]]''
| type_species_authority = [[Heinrich Friedrich Link|Link]], 1795<br />(''Lepus dauuricus'' [[Peter Simon Pallas|Pallas]], 1776)
| subdivision_ranks = Species
| subdivision = See [[#Taxonomy|text]]
| range_map = 
| range_map_caption = 
}} 

A '''pika''' ({{IPAc-en|ˈ|p|iː|k|ə}} {{respell|PEE|kə}},<ref name=dict2>{{cite web |url=https://oed.com/dictionary/pika_n1?tab=factsheet#30143840 |title=Pika |website=[[Oxford English Dictionary]] |publisher=[[Oxford University Press]] |access-date=2024-10-06}}</ref> {{IPAc-en|USalso|ˈ|p|aɪ|k|ə}} {{respell|PY|kə}})<ref name=dict>{{cite Collins Dictionary|pika |access-date=2024-04-01}}</ref> 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.<ref>{{cite web |url=https://treehugger.com/animals/what-know-about-mouse-bunny-could-vanish-states.html |title=Meet the 'mouse-bunny' that could vanish from the US |author=Breyer, M. |date=2016-09-02 |publisher=[[TreeHugger]]}}</ref> The [[large-eared pika]] of the [[Himalayas]] and nearby mountains lives at elevations of more than {{cvt|6000|m|ft}}.

The name ''pika'' appears to be derived from the [[Tungusic languages|Tungusic]] ''piika'',<ref>{{OEtymD|pika}}</ref><ref name="Twycrosszoo">{{Cite web |last1=Fox |first1=Nikki |title=''Ochotona'' - |url=http://wildpro.twycrosszoo.org/S/0MLagomorph/Ochotonidae/Ochotona/Ochotona.htm |archive-url=https://web.archive.org/web/20200124185306/http://wildpro.twycrosszoo.org/S/0MLagomorph/Ochotonidae/Ochotona/Ochotona.htm |archive-date=January 24, 2020 |access-date=18 June 2025 |website=Wildpro |publisher=[[Twycross Zoo]]}}</ref> and the scientific name ''Ochotona'' is derived from the [[Mongolian language|Mongolian]] word ''ogotno'' ({{lang|mn|оготно}}), which means 'pika'.<ref>[http://wildpro.twycrosszoo.org/S/0MLagomorph/Ochotonidae/Ochotona/ochotona_hoffmanni.htm#Synonyms General pika information] {{webarchive|url=https://web.archive.org/web/20170510133417/http://wildpro.twycrosszoo.org/S/0MLagomorph/Ochotonidae/Ochotona/ochotona_hoffmanni.htm |date=2017-05-10 }}. twycrosszoo.org</ref> It is used for any member of the '''Ochotonidae''' ({{IPAc-en|ˌ|ɒ|k|@|'|t|oU|n|I|d|eI}}),<ref name="EB1911">{{Cite EB1911 |wstitle=Pica (rodent) |display=Pica |volume=21 |page=575 |first=Richard |last=Lydekker}}</ref> a [[Family (biology)|family]] within the [[order (biology)|order]] of [[Lagomorpha|lagomorph]]s, the order which also includes the [[Leporidae]] (rabbits and [[hare]]s). They are the smallest animal in the lagomorph group.<ref>{{Cite web |title=American Pika |url=https://www.nwf.org/Home/Educational-Resources/Wildlife-Guide/Mammals/American-Pika |access-date=2023-10-19 |website=National Wildlife Federation |language=en}}</ref> Only one [[genus]], '''''Ochotona'''''<ref name="EB1911" /> ({{IPAc-en|ˌ|ɒ|k|ə|ˈ|t|oʊ|n|ə}} {{respell|OK|ə|TOHN|ə}}), 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 2,000 years owing to human activity.

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 under rocks to eat during the long, cold winter.<ref>{{Cite book|title=Encyclopedia of animals|last=Walters|first=Martin|publisher=Parragon|year=2005|isbn=978-1-40545-669-2|page=203}}</ref> The pika is also known as the whistling hare because of its high-pitched [[alarm call]] it gives when alarmed. 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==
[[File:Collared Pika - Hatchers Pass Alaska.jpg|thumb|left|[[Collared pika]] on Hatcher Pass, [[Alaska]]]]

Pikas are native to cold climates in [[Asia]] and [[North America]]. Most species live on rocky mountain sides, 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 [[snowfinch]]es, which build their nests there.<ref name=EoM>{{cite book|editor= Macdonald, D.|author= Kawamichi, Takeo|year= 1984|title= The Encyclopedia of Mammals|publisher= Facts on File|location= New York|pages= [https://archive.org/details/encyclopediaofma00mals_0/page/726 726]–727|isbn= 978-0-87196-871-5|url-access= registration|url= https://archive.org/details/encyclopediaofma00mals_0}}</ref> Changing temperatures have forced some pika populations to restrict their ranges to even higher elevations.<ref>{{Cite journal|last1=Erb|first1=Liesl P|last2=Ray|first2=Chris|last3=Guralnick|first3=Robert|date=2011-09-01|title=On the generality of a climate-mediated shift in the distribution of the American pika (''Ochotona princeps'')|journal=Ecology|volume=92|issue=9|pages=1730–1735|doi=10.1890/11-0175.1|pmid=21939069|bibcode=2011Ecol...92.1730E |doi-access=free}}</ref>

==Characteristics==
Pikas are small mammals, with short limbs and rounded ears. They are about {{convert|15|to|23|cm|in|abbr=on}} in body length and weigh between {{convert|120|and|350|g|oz|abbr=on}}, depending on species.

These animals are [[herbivore]]s and feed on a wide variety of plant matter, including [[forb]]s, [[Poaceae|grasses]], [[Cyperaceae|sedge]]s, shrub twigs, moss and lichens. Easily digestible food is processed in the gastrointestinal tract and expelled as regular feces.  But in order to get nutrients out of hard to digest fiber, pika ferment fiber in the cecum (in the GI tract) and then expel the contents as soft pellets, or [[cecotrope]]s, which are reingested. This process is known as cecotrophy, and is a common behavior among all lagomorphs. The cecotropes are absorbed in the small intestine after consumption to utilize the nutrients.<ref name="Twycrosszoo" />

Collared pikas have been known to store dead birds in their burrows for food during winter and eat the feces of other animals.<ref name="AnimalDiversity" />

As with other lagomorphs, pikas have gnawing [[incisor]]s and no [[canine (tooth)|canine]]s, although they have fewer [[molar (tooth)|molars]] than rabbits.  They have a [[dentition|dental formula]] of {{DentalFormula|upper=2.0.3.2|lower=1.0.2.3}} = 26.<ref>{{Cite book |last=Elbroch |first=Mark |title=Animal Skulls: A Guide to North American Species |publisher=[[Stackpole Books]] |year=2006 |isbn=978-0-8117-3309-0 |location=Mechanicsburg, PA |page=248}}</ref> Another similarity that pikas share with other lagomorphs is that the bottom of their paws are covered with fur and lack paw pads.<ref>{{Cite web|title=Pika {{!}} mammal|url=https://www.britannica.com/animal/pika|access-date=2021-06-26|website=Encyclopedia Britannica|language=en}}</ref>

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 altricial (eyes and ears closed, no fur) after a [[gestation]] period of between 25 and 30 days.<ref name=EoM/>

==Activity==
[[File:Pika pile.JPG|thumb|Vegetation pile drying on rocks for subsequent storage, [[Little Cottonwood Canyon]], [[Utah]]]]
[[File:Ochotona princeps pika haying in rocks.jpg|thumb|American pika with mouthful of dried grass, [[Sequoia National Park]], [[California]]]]

Pikas are active during daylight ([[Diurnality|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 [[hibernation|hibernate]] and remain active throughout the winter by traveling in tunnels under rocks and snow and eating dried plants that they have stored.<ref>{{Cite web |date=August 21, 2018 |title=American Pikas |url=https://www.nps.gov/band/learn/nature/pika.htm |access-date=January 18, 2024 |website=National Park Service}}</ref> Rock-dwelling pikas exhibit two methods of foraging: the first involves direct consumption of food, and the second is characterized by the gathering of plants to store in a "haypile" of cached plants.<ref>{{Cite book |last1=Smith |first1=Andrew T. |title=Lagomorphs: Pikas, Rabbits, and Hares of the World |last2=Charlotte H. |first2=Charlotte H. |last3=Alves |first3=Paulo C. |last4=Hackländer |first4=Klaus |date=January 1, 2018 |publisher=Johns Hopkins University Press |isbn=978-1-4214-2340-1 |publication-date=January 1, 2018 |pages=69 |language=English}}</ref>

The impact of human activity on the [[tundra]] ecosystems where pikas live has been recorded dating back to the 1970s.<ref>Brown, R. W., R. S. Johnston, and K. Van Cleve. "Rehabilitation problems of [[Arctic]] and alpine regions." ''Reclamation of drastically disturbed lands'' (1978): 23-44.</ref> 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".  They eat the dried plants during the winter.<ref>Dearing, M. Denise. "The function of haypiles of pikas (''Ochotona princeps'')." ''Journal of Mammalogy'' 78.4 (1997): 1156-1163. APA</ref> When pikas mistake humans as predators, they may respond to humans as they do to other species that do prey on 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.<ref name="Stafl-2015">{{Cite journal|last1=Stafl|first1=Natalie|last2=O'Connor|first2=Mary I.|date=2015-08-01|title=American Pikas' (''Ochotona princeps'') Foraging Response to Hikers and Sensitivity to Heat in an Alpine Environment|journal=Arctic, Antarctic, and Alpine Research|volume=47|issue=3|pages=519–527|doi=10.1657/AAAR0014-057|bibcode=2015AAAR...47..519S |s2cid=86263545|issn=1523-0430}}</ref> Pikas prefer foraging in temperatures below {{convert|25|C}}, so they generally spend their time in shaded regions and out of direct sunlight when temperatures are high.<ref name="Stafl-2015" /> A link has also been found between temperature increases and lost foraging time, where for every increase of {{cvt|1|C-change}} to the ambient temperature in alpine landscapes home to pikas, those pikas lose 3% of their foraging time.<ref name="Stafl-2015" />

Eurasian pikas commonly live in family groups and share duties of gathering food and keeping watch. Some species are territorial. North American pikas (''[[American pika|O. princeps]]'' and ''[[O. collaris]]'') are [[wiktionary:asocial|asocial]], leading solitary lives outside the breeding season.<ref name=AnimalDiversity>{{cite web |url= http://animaldiversity.ummz.umich.edu/accounts/Ochotona_collaris/ |title= ''Ochotona collaris''|last= Leininger |first= Charlene |date= 2009 |website= Animal Diversity Web|publisher= |access-date= March 23, 2021|archive-url=https://web.archive.org/web/20130628150601/http://animaldiversity.ummz.umich.edu/accounts/Ochotona_collaris/ |archive-date=2013-06-28 }}</ref>

==Vocalization==
Pikas have distinct [[Animal language|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.<ref>{{Cite journal|title = Geographic Variation in Short Calls of Pikas (''Ochotona princeps'')|journal = Journal of Mammalogy|date = 1982-02-25|pages = 48–52|volume = 63|issue = 1|doi = 10.2307/1380670|first = Douglas A.|last = Conner|jstor = 1380670}}</ref> The calls are used for individual recognition, predator warning signals, territory defense, or as a way to attract potential mates.<ref>{{Cite journal|last1=Trefry|first1=Sarah A.|last2=Hik|first2=David S.|date=2009|title=Variation in pika (''Ochotona collaris, O. princeps'') vocalizations within and between populations|journal=Ecography|volume=33|issue=4|pages=784–795|doi=10.1111/j.1600-0587.2009.05589.x|doi-access=free}}</ref> 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.<ref>{{cite journal|title = Dialects in southern Rocky Mountain pikas, ''Ochotona princeps'' (Lagomorpha)|doi = 10.1016/S0003-3472(73)80050-8|volume=21|journal=Animal Behaviour|pages=124–137|year = 1973|last1 = Somers|first1 = Preston| issue=1 }}</ref>

==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 [[Periosteum|periosteal]] bone on the lower jaw. The lifespan does not differ between the sexes.<ref>{{Cite journal|title = Age determination in yellow-pine chipmunks (''Tamias amoenus''): a comparison of eye lens masses and bone sections|journal = Canadian Journal of Zoology|date = 2003-10-01|pages = 1774–1779|volume = 81|issue = 10|doi = 10.1139/z03-173|first1 = Jennifer M|last1 = Barker|first2 = Rudy|last2 = Boonstra|first3 = Albrecht I|last3 = Schulte-Hostedde}}</ref>

==Taxonomy==
{{main|List of ochotonids}}
The 29 extant species of pika currently recognized are:
* '''Order Lagomorpha'''<ref name=MSW/>
** '''Family Ochotonidae''': pikas
*** Genus '''''Ochotona'''''
**** Subgenus ''Conothoa'': mountain pikas
***** [[Chinese red pika]], ''O. erythrotis''
***** [[Forrest's pika]], ''O. forresti''
***** [[Glover's pika]], ''O. gloveri''
***** [[Ili pika]], ''O. iliensis''
***** [[Koslov's pika]], ''O. koslowi''
***** [[Ladak pika]], ''O. ladacensis''
***** [[Large-eared pika]], ''O. macrotis''
***** [[Royle's pika]], ''O. roylei''
***** [[Turkestan red pika]], ''O. rutila''
****Subgenus ''Ochotona'': shrub-steppe pikas
***** [[Gansu pika]] or gray pika, ''O. cansus''
***** [[Plateau pika]] or black-lipped pika, ''O. curzoniae''
***** [[Daurian pika]], ''O. dauurica''
***** [[Nubra pika]], ''O. nubrica''
***** [[Steppe pika]], ''O. pusilla''
***** [[Afghan pika]], ''O. rufescens''
*****[[Tsing-ling pika]], ''O. syrinx''
***** [[Moupin pika]], ''O. thibetana''
***** [[Thomas's pika]], ''O. thomasi''
****Subgenus ''Pika'': northern pikas{{Anchor |Pika (subgenus)}}
***** [[Alpine pika]] or Altai pika, ''O. alpina''
***** [[Helan Shan pika]] or silver pika, ''O. argentata''
***** [[Collared pika]], ''O. collaris''
*****[[Korean pika]], ''O. coreana''
***** [[Hoffmann's pika]], ''O.  hoffmanni''
***** [[Northern pika]] or Siberian pika, ''O. hyperborea''
*****[[Manchurian pika]], ''O. mantchurica''
*****[[Kazakh pika]], ''O. opaca''
***** [[Pallas's pika]], ''O. pallasii''
***** [[American pika]], ''O. princeps''
***** [[Turuchan pika]], ''O. turuchanensis''

===Extinct species===
Many fossil forms of ''Ochotona'' are described in the literature, from the [[Miocene]] epoch to the early [[Holocene]] ([[Extinction|extinct]] species) and present (16.4-0 [[Megaannum#SI prefix multipliers|Ma]]<ref name="Ge13" />). They lived in Europe, Asia, and North America.Some species listed below are common for Eurasia and North America (''O. gromovi'', ''O. tologoica'', ''O. zazhigini'', and probably ''O. whartoni'').

* Eurasia
** large forms
*** †''[[Ochotona chowmincheni]]'' ([[China]]: [[Baode]] area, late Miocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona gromovi]]'' ([[Asia]], [[Pliocene]], see also North America)<ref name="Erbajeva11" />
*** †''[[Ochotona gudrunae]]'' (China: [[Shanxi]], early [[Pleistocene]])<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona guizhongensis]]'' ([[Tibet]], late Miocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Cai89" />
*** †''[[Ochotona lagreli]]'' (China: [[Inner Mongolia]], late Miocene to late Pliocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" /><ref name="Cai89" />
*** †''[[Ochotona magna]]'' (China, early Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
*** †''[[Ochotona tologoica]]'' ([[Transbaikal]]ia, Pliocene, see also North America)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
*** †''[[Ochotona transcaucasica]]'' ([[Transcaucasia]]: eastern [[Georgia (country)|Georgia]] and [[Azerbaijan]], Transbaikal and probably southern Europe, early to late Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona ursui]]'' ([[Romania]], Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona zasuchini]]'' (Transbaikalia, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
*** †''[[Ochotona zazhigini]]'' (Asia, Pliocene, see also North America)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona zhangi]]'' (China, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva05" />
**medium-sized forms
*** †''[[Ochotona agadjianiani]]'' (Asia, Pliocene)<ref name="Erbajeva11" />
*** †''[[Ochotona antiqua]]'' ([[Moldavia]], [[Ukraine]], and the [[Russia]]n Plain, [[Caucasus]], and probably [[Rhodes]], late Miocene to Pliocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona azerica]]'' (Transcaucasia: Azerbaijan,<ref name="Cermak06" /> middle Pliocene)<ref name="Ge13" /><ref name="Erbajeva05" />
*** †''[[Ochotona lingtaica]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona dodogolica]]'' (Asia: western Transbaikalia, Pleistocene)<ref name="Fostowicz10" /><ref name="Erbajeva11" />
*** †''[[Ochotona nihewanica]]'' (China: [[Hebei]], early Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" /><ref name="Erbajeva03" />
*** †''[[Ochotona plicodenta]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona polonica]]'' (Europe: [[Poland]], [[Germany]], [[France]], Pliocene)<ref name="Ge13" /><ref name="Fostowicz10" /><ref name="Erbajeva11" />
** small-sized forms
*** †''[[Ochotona bazarovi]]'' (Asia, upper Pliocene)<ref name="Ge13" /><ref name="Erbajeva05" /><ref name="Erbajeva03" />
*** †''[[Ochotona dehmi]]'' (Germany: [[Schernfeld]], Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona filippovi]]'' ([[Siberia]], Pleistocene)<ref name="Ge13" /><ref name="Erbajeva03" />
*** †''[[Ochotona gracilis]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona horaceki]]'' ([[Slovakia]]: [[Honce]], Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona minor]]'' (China, late Miocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Cai89" />
*** †''[[Ochotona sibirica]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona valerotae]]'' ([[France]]: Valerots site, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona youngi]]'' (Asia, Pliocene)<ref name="Erbajeva11" /><br />and others.<ref name="Ge13" /><ref name="Erbajeva11" />
** other examples
*** †''[[Ochotona agadzhaniani]]'' (Transcaucasia: [[Armenia]], Pliocene)<ref name="Ge13" />
*** †''[[Ochotona alaica]]'' (Asia: [[Kyrgyzstan]], Pleistocene)<ref name="Ge13" />
*** †[[Ochotona eximia|''Ochotona'' (''Proochotona'') ''eximia'']] ([[Moldova]], Ukraine, Russia, [[Kazakhstan]], Miocene to Pliocene)<ref name="Ge13" />
*** †[[Ochotona gigas|''Ochotona'' (''Proochotona'') ''gigas'']] (Ukraine, Pliocene)<ref name="Ge13" />
*** †''[[Ochotona gureevi]]'' (Transbaikalia, middle Pliocene)<ref name="Ge13" /><ref name="Erbajeva05" />
*** †''[[Ochotona hengduanshanensis]]'' (China, Pleistocene)<ref name="Ge13" />
*** †''[[Ochotona intermedia]]'' (Asia, Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †[[Ochotona kalfaense|''Ochotona'' (''Proochotona'') ''kalfaense'']] (Europe: [[Moldova]], Miocene)<ref name="Ge13" />
*** †[[Ochotona kirgisica|''Ochotona'' (''Proochotona'') ''kirgisica'']] (Asia: Kyrgyzstan, Pliocene)<ref name="Ge13" />
*** †''[[Ochotona kormosi]]'' ([[Hungary]], Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" />
*** †[[Ochotona kurdjukovi|''Ochotona'' (''Proochotona'') ''kurdjukovi'']] (Asia: Kyrgyzstan, Pliocene)<ref name="Ge13" />
*** †''[[Ochotona largerli]]'' (Georgia, Pleistocene)<ref name="Ge13" />
*** †''[[Ochotona lazari]]'' (Ukraine, Pleistocene)<ref name="Ge13" />
*** †''[[Ochotona mediterranensis]]'' ([[Turkey]], Pliocene)<ref name="Ge13" />
*** †''[[Ochotona ozansoyi]]'' (Turkey, Miocene)<ref name="Ge13" />
*** †''[[Ochotona pseudopusilla]]'' (Ukraine and Russian Plain, Pleistocene)<ref name="Ge13" /><ref name="Erbajeva11" />
*** †''[[Ochotona spelaeus]]'' (Ukraine, late Pleistocene)<ref name="Ge13" /><ref name="Rekovets" />
*** †''[[Ochotona tedfordi]]'' (China: [[Yushe Basin]], late Miocene)<ref name="Ge13" /><ref name="Fostowicz10" />
*** †''[[Giant pika|Ochotona cf. whartoni]]'' ([[Irkutsk Oblast]] and [[Sakha Republic|Yakutia]], Pleistocene, see also North America)<ref name="Erbajeva11" />
*** †''[[Ochotona zabiensis]]'' (southern [[Poland]], early Pleistocene)<ref name="Ge13" /><ref name="Fostowicz10" />
*** †''Ochotona'' sp. ([[Greece]]: [[Maritsa]], Pliocene)<ref name="Erbajeva11" />
*** †''Ochotona'' sp. (Hungary: [[Ostramos]], Pleistocene)<ref name="Erbajeva11" />
*** †''Ochotona'' sp. (Siberia, Pleistocene)<ref name="Erbajeva11" />
*** †''Ochotona'' sp. (Yakutia, Pleistocene)<ref name="Erbajeva11" />
* North America
** †''[[Ochotona gromovi]]'' ([[United States|US]]: [[Colorado]], Pliocene, see also Eurasia)<ref name="Ge13" />
** †''[[Ochotona spanglei]]'' (US, late Miocene or early Pliocene)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva03" /><ref name="Shotwell56" /><ref name="PaleoDBOspan" />{{refn|group=n|name=b|''Ochotona spanglei'' in the Paleobiology Database.<ref name="PaleoDBOspan" /><ref group=pdb name="Shotwell56" /><ref group=pdb name="Voorhies90" /><ref group=pdb name="PaleoDBOspan2" />}}
** †''[[Ochotona tologoica]]'' (US: Colorado, Pliocene, see also Eurasia)<ref name="Ge13" />
** †''Ochotona whartoni'' ([[giant pika]], US, [[Canada]], Pleistocene to early Holocene, see also Eurasia)<ref name="Ge13" /><ref name="Erbajeva11" /><ref name="Erbajeva03" /><ref name="GuthrieMatthews71" /><ref name="PaleoDBOwhar" />{{refn|group=n|name=c|''Ochotona whartoni'' in the Paleobiology Database.<ref name="PaleoDBOwhar" /><ref group=pdb name="Guthrie71" /><ref group=pdb name="Jopling81" /><ref group=pdb name="Harington78" /><ref group=pdb name="Harington90" /><ref group=pdb name="Storer04" /><ref group=pdb name="Tedford09" /><ref group=pdb name="PaleoDBOwhar2" />}}
** †''[[Ochotona wheatleyi]]'' (US: [[Alaska]], Pliocene, late Pleistocene)<ref name="Ge13" />
** †''[[Ochotona zazhigini]]'' (US: Colorado, Pleistocene, see also Eurasia)<ref name="Ge13" />
** extinct small pikas similar to the ''[[Steppe pika|O. pusilla]]'' group (Pleistocene)<ref name="Erbajeva11" /><ref name="Erbajeva03" />

Paleontologists have also described multiple forms of pika not referred to specific species (''Ochotona'' indet.) or not certainly identified (''O.'' [[cf.]] ''antiqua'', ''O.'' cf. ''cansus'', ''O.'' cf. ''daurica'', ''O.'' cf. ''eximia'', ''O.'' cf. ''gromovi'', ''O.'' cf. ''intermedia'', ''O.'' cf. ''koslowi'', ''O.'' cf. ''lagrelii'', ''O.'' cf. ''nihewanica''). The statuses of ''Ochotona'' (''Proochotona'') ''kirgisica'' and ''O. spelaeus'' are uncertain.<ref name="Ge13" /> The "''pusilla''" group of pikas is characterized by archaic ([[Symplesiomorphy|plesiomorphic]]) cheek teeth and small size.<ref name="Erbajeva03" /> Pikas on the whole have been described as "one of the most complex and problematic groups in mammalian systematics".<ref>{{Cite journal |last=Yu |first=Ning |last2=Zheng |first2=Changlin |last3=Zhang |first3=Ya-Ping |last4=Li |first4=Wen-Hsiung |date=2000-07-01 |title=Molecular Systematics of Pikas (Genus Ochotona) Inferred from Mitochondrial DNA Sequences |url=https://www.sciencedirect.com/science/article/pii/S1055790300907760 |journal=Molecular Phylogenetics and Evolution |volume=16 |issue=1 |pages=85–95 |doi=10.1006/mpev.2000.0776 |issn=1055-7903|url-access=subscription }}</ref>

The North American species migrated from Eurasia. They invaded the New World twice:

* ''O.  spanglei'' during the latest Miocene or early Pliocene, followed by a roughly three-million-year-long gap in the known North American pika record<ref name="Erbajeva11" />
*''O.  whartoni'' (giant pika) and small pikas via the [[Beringia|Bering Land Bridge]] during the earliest Pleistocene<ref name="Erbajeva11" />

''Ochotona'' [[cf.]] ''whartoni'' and small pikas of the ''O. pusilla'' group are also known from Siberia. The extant, [[endemic]] North American species appeared in the Pleistocene. The North American collared pika (''O. collaris'') and [[American pika]] (''O. princeps'') have been suggested to have descended from the same ancestor as the steppe pika (''O. pusilla'').<ref name="Erbajeva11" />

The range of ''Ochotona'' was larger in the past, with both extinct and extant species inhabiting Western Europe and Eastern North America, areas that are currently free of pikas. Pleistocene fossils of the extant steppe pika ''O. pusilla'' currently native to Asia have been found also in many countries of Europe from the [[United Kingdom]] to Russia and from [[Italy]] to Poland, and the Asiatic extant northern pika ''O. hyperborea'' in one location in the middle Pleistocene United States.<ref name="Ge13" />

[[File:Pika Ochotona sp. fossil distribution 2.png|thumb|center|720px|Pika ''Ochotona'' sp. fossil distribution. [[Extinction|Extinct]] pikas and ''Ochotona'' indet. are {{color|red|red}}, [[steppe pika]] ''O. pusilla'' {{color|blue|blue}}, [[northern pika]] ''O. hyperborea'' {{color|green|green}}, other [[extant taxon|extant]] pikas black.<ref name="Ge13" /><ref name="PaleoDBO" />{{refn|group=n|name=a|The coordinates of additional fossils not listed in the xls file attached to Ge and all paper<ref name="Ge13" /> were taken from the Paleobiology Database.<ref name="PaleoDBO" /><ref group=pdb name="Barnosky88" /><ref group=pdb name="Belyaeva48" /><ref group=pdb name="Bonifay73" /><ref group=pdb name="Cai87" /><ref group=pdb name="Deng11" /><ref group=pdb name="Erbaeva86" /><ref group=pdb name="Frazier97" /><ref group=pdb name="Gidley13" /><ref group=pdb name="Grady00" /><ref group=pdb name="Guilday79" /><ref group=pdb name="Harington78" /><ref group=pdb name="Harington90" /><ref group=pdb name="Janossy70" /><ref group=pdb name="Janossy86" /><ref group=pdb name="Jopling81" /><ref group=pdb name="Kurten80" /><ref group=pdb name="Mead96" /><ref group=pdb name="Qiu87" /><ref group=pdb name="Rasmussen74" /><ref group=pdb name="Sotnikova97" /><ref group=pdb name="Terzea96" /><ref group=pdb name="Winkler90" /><ref group=pdb name="PaleoDBO2" />}}]]

[[File:Fossil occurrences of leporids and ochotonids and global environmental change.png|thumb|[[Fossil]] occurrences of [[Leporidae|leporids]] and ochotonids and global environmental change ([[climate change]], [[C3 carbon fixation|C<sub>3</sub>]]/[[C4 carbon fixation|C<sub>4</sub>]] plants distribution)<ref name="Ge13" />]]

While ''Ochotona'' is the only currently living genus of Ochotonidae, extinct [[Genus|genera]] of ochotonids include  †''[[Albertona]]'', †''[[Alloptox]]'', †''[[Amphilagus]]'', †''[[Australagomys]]'', †''[[Austrolagomys]]'', †''[[Bellatona]]'', †''[[Bellatonoides]]'', †''[[Bohlinotona]]'', †''[[Cuyamalagus]]'', †''[[Desmatolagus]]'', †''[[Eurolagus]]'', †''[[Gripholagomys]]'', †''[[Gymnesicolagus]]'', †''[[Hesperolagomys]]'', †''[[Heterolagus]]'', †''[[Kenyalagomys]]'', †''[[Lagopsis (animal)|Lagopsis]]'', †''[[Marcuinomys]]'', †''[[Ochotonoides]]'', †''[[Ochotonoma]]'', †''[[Oklahomalagus]]'', †''[[Oreolagus]]'', †''[[Paludotona]]'', †''[[Piezodus]]'', †''[[Plicalagus]]'', †''[[Pliolagomys]]'', †''[[Prolagus]]'', †''[[Proochotona]]'' ([[Synonym (taxonomy)|syn.]] ''Ochotona''), †''[[Pseudobellatona]]'', †''[[Ptychoprolagus]]'', †''[[Russellagus]]'', †''[[Sinolagomys]]'', †''[[Titanomys]]'' and †''[[Tonomochota]]''.<ref name="Ge13" /><ref>{{cite journal|last1=Tiunov|first1=Mikhail P.|last2=Gusev|first2=Alexander E.|year=2021|title=A new extinct ochotonid genus from the Late Pleistocene of the Russian Far East|journal=Palaeoworld|volume=30|issue=3|pages=562–572|doi=10.1016/j.palwor.2020.08.003}}</ref> The earliest one is ''Desmatolagus'' (middle Eocene to Miocene, 42.5–14.8 Ma<ref name="Ge13" />), usually included in the Ochotonidae, sometimes in [[Leporidae]] or in neither ochotonid nor leporid stem-[[Lagomorpha|lagomorphs]].<ref name="Hordijk10" />

Ochotonids appeared in Asia between the late Eocene and the early Oligocene, and continued to develop along with increased distribution of [[C3 carbon fixation|C<sub>3</sub> grasses]] in previously forest dominated areas under the "climatic optimum" from the late Oligocene to middle Miocene. They thrived in Eurasia, North America, and even Africa. The peak of their diversity occurred during the period from the early Miocene to middle Miocene.  Most of them became extinct during the transition from the Miocene to Pliocene, which was accompanied by  an increase in diversity of the ''[[Leporidae|leporids]]''. It has been proposed that this switch between ochotonids and larger leporids was caused by expansion of [[C4 carbon fixation|C<sub>4</sub> plants]] (particularly the [[Poaceae]]) related to global cooling in the late Miocene, since extant pikas reveal a strong preference for [[C3 carbon fixation|C<sub>3</sub> plants]] ([[Asteraceae]], [[Rosaceae]], and [[Fabaceae]], many of them C<sub>3</sub>). Replacement of large areas of forests by open grassland first started probably in North America and is called sometimes "nature's green revolution".<ref name="Ge13" />

==Notes==
{{Reflist|group=n}}

==References==
{{Reflist |30em|refs=

<ref name="GuthrieMatthews71">{{cite journal |last1=Guthrie |first1=R.D. |last2=Matthews |first2=John V. Jr. |year=1971 |title=The Cape Deceit fauna—Early pleistocene mammalian assemblage from the Alaskan arctic |journal=Quaternary Research |volume=1 |issue=4 |pages=474–510 |doi=10.1016/0033-5894(71)90060-3 |bibcode=1971QuRes...1..474G |s2cid=86601856 }}</ref>

<ref name="Erbajeva11">{{cite journal |last1=Erbajeva |first1=Margarita A. |last2=Mead |first2=Jim I. |last3=Alexeeva |first3=Nadezhda V. |last4=Angelone |first4=Chiara |last5=Swift |first5=Sandra L. |year=2011 |title=Taxonomic diversity of Late Cenozoic Asian and North American ochotonids (an overview) |journal=Palaeontologia Electronica |pages=1–9 |url=http://palaeo-electronica.org/2011_3/25_erbajeva/25_erbajeva.pdf |access-date=April 13, 2014 |url-status=live |archive-url=https://web.archive.org/web/20140414125811/http://palaeo-electronica.org/2011_3/25_erbajeva/25_erbajeva.pdf |archive-date=April 14, 2014 }}</ref>

<ref name="Erbajeva03">{{cite journal |last1=Erbajeva |first1=Margarita A. |last2=Mead |first2=Jim I. |last3=Swift |first3=Sandra L. |year=2003 |title=Evolution and development of Asian and North American ochotonids |journal=Occasional Papers in Earth Sciences No. 5 |pages=33–34 |url=http://www.tc.gov.yk.ca/publications/IMC_Program_Abtracts_2003.pdf |access-date=April 13, 2014 |quote=3rd INTERNATIONAL MAMMOTH CONFERENCE, 2003: PROGRAM AND ABSTRACTS, Edited by John E. Storer |archive-url=https://web.archive.org/web/20140331063450/http://www.tc.gov.yk.ca/publications/IMC_Program_Abtracts_2003.pdf |archive-date=March 31, 2014 }}</ref>

<ref name="Rekovets">{{cite journal |last=Rekovets |first=Leonid |year=2003 |title=Mammoth (Mammuthus primigenius) in the periglacial faunas of Ukraine |journal=Occasional Papers in Earth Sciences No. 5 |pages=130–131 |url=http://www.tc.gov.yk.ca/publications/IMC_Program_Abtracts_2003.pdf |access-date=April 13, 2014 |quote=3rd INTERNATIONAL MAMMOTH CONFERENCE, 2003: PROGRAM AND ABSTRACTS, Edited by John E. Storer |archive-url=https://web.archive.org/web/20140331063450/http://www.tc.gov.yk.ca/publications/IMC_Program_Abtracts_2003.pdf |archive-date=March 31, 2014 }}</ref>

<ref name="PaleoDBOspan">{{cite web |url=http://paleobiodb.org/cgi-bin/bridge.pl?a=basicTaxonInfo&taxon_no=49268 |title=''Ochotona spanglei'' Shotwell 1956 |author=<!--Staff writer(s); no by-line.--> |work=The Paleobiology Database |url-status=live |archive-url=https://web.archive.org/web/20140415211429/http://paleobiodb.org/cgi-bin/bridge.pl?a=basicTaxonInfo&taxon_no=49268 |archive-date=April 15, 2014 }}</ref>

<ref name="PaleoDBOwhar">{{cite web |url=http://paleobiodb.org/cgi-bin/bridge.pl?a=basicTaxonInfo&taxon_no=49269 |title=''Ochotona whartoni'' Guthrie and Matthews, Jr. 1971 (pika) |author=<!--Staff writer(s); no by-line.--> |work=The Paleobiology Database |url-status=live |archive-url=https://web.archive.org/web/20140414134356/http://paleobiodb.org/cgi-bin/bridge.pl?a=basicTaxonInfo&taxon_no=49269 |archive-date=April 14, 2014 }}</ref>

<ref name="Shotwell56">{{cite journal |last=Shotwell |first=J. Arnold |year=1956 |title=Hemphillian mammalian assemblage from northeastern Oregon |journal=Geological Society of America Bulletin |volume=67 |issue=6 |pages=717–738 |doi=10.1130/0016-7606(1956)67[717:HMAFNO]2.0.CO;2 |bibcode=1956GSAB...67..717S }}</ref>

<ref name="Cai89">{{cite journal |last=Cai |first=Baoquan |year=1989 |title=Fossil Lagomorpha from the Late Pliocene of Yangyuan and Yuxian counties, Hebei Province |journal=Vertebrata PalAsiatica |volume=XXVII |issue=3 |pages=170–181 |url=http://nau.edu/uploadedFiles/Academic/CEFNS/NATSCI/SESES/Forms/fossillagomorpha.pdf |access-date=May 20, 2014 |quote=Translated by Will Downs Department of Geology Bilby Research Center Northern Arizona University October, 1990 |url-status=live |archive-url=https://web.archive.org/web/20160305025504/http://nau.edu/uploadedFiles/Academic/CEFNS/NATSCI/SESES/Forms/fossillagomorpha.pdf |archive-date=March 5, 2016 }}</ref>

<ref name="Fostowicz10">{{cite journal |last1=Fostowicz-Frelik |first1=Łucja |last2=Frelik |first2=Grzegorz |last3=Gasparik |first3=Mihály |date=October 2010 |title=Morphological phylogeny of pikas (Lagomorpha: ''Ochotona''), with a description of a new species from the Pliocene/Pleistocene transition of Hungary |journal=Proceedings of the Academy of Natural Sciences of Philadelphia |volume=159 |pages=97–117 |doi=10.1635/053.159.0107 |jstor=41446115|s2cid=83700561 }}</ref>

<ref name="Erbajeva05">{{cite journal |last1=Erbajeva |first1=Margarita A. |last2=Zheng |first2=Shaohua |date=30 June 2005 |title=New data on Late Miocene – Pleistocene ochotonids (Ochotonidae, Lagomorpha) from North China |journal=Acta Zoologica Cracoviensia |volume=48A |issue=1–2 |pages=93–117 |url=http://www.isez.pan.krakow.pl/journals/azc_v/pdf/48A%281-2%29/08.pdf |access-date=May 20, 2014 |doi=10.3409/173491505783995734 |url-status=live |archive-url=https://web.archive.org/web/20170510103159/http://www.isez.pan.krakow.pl/journals/azc_v/pdf/48A%281-2%29/08.pdf |archive-date=May 10, 2017 }}</ref>

<ref name="Cermak06">{{cite journal |last1=Čermák |first1=Stanislav |first2=Ján |last2=Obuch |last3=Benda |first3=Petr |year=2006 |title=Notes on the genus ''Ochotona'' in the Middle East (Lagomorpha: Ochotonidae) |journal=Lynx |volume=37 |pages=51–66 |issn=0024-7774 |url=http://www.nm.cz/download/pm/zoo/benda_lit/Cermak2006lynx.pdf |access-date=May 22, 2014 |archive-url=https://web.archive.org/web/20140522143140/http://www.nm.cz/download/pm/zoo/benda_lit/Cermak2006lynx.pdf |archive-date=May 22, 2014 }}</ref>

<ref name="Ge13">{{cite journal |last1=Ge |first1=Deyan |last2=Wen |first2=Zhixin |last3=Xia |first3=Lin |last4=Zhang |first4=Zhaoqun |last5=Erbajeva |first5=Margarita |last6=Huang |first6=Chengming |last7=Yang |first7=Qisen |date=April 3, 2013 |title=Evolutionary History of Lagomorphs in Response to Global Environmental Change |journal=PLOS ONE |volume=8 |issue=4:e59668 |doi=10.1371/journal.pone.0059668|article-number=e59668 |pmid=23573205 |pmc=3616043 |bibcode=2013PLoSO...859668G |doi-access=free }} [http://s3-eu-west-1.amazonaws.com/files.figshare.com/1009822/Table_S1.xls Table_S1.xls] {{webarchive|url=https://web.archive.org/web/20140522194644/http://s3-eu-west-1.amazonaws.com/files.figshare.com/1009822/Table_S1.xls |date=2014-05-22 }}</ref>

<ref name="PaleoDBO">{{cite web |url=http://paleobiodb.org/cgi-bin/bridge.pl?a=basicTaxonInfo&taxon_no=42159 |title= ''Ochotona'' Link 1795 (pika) |author=<!--Staff writer(s); no by-line.--> |work=The Paleobiology Database}}</ref>

<ref name="Hordijk10">{{cite book |last=Hordijk |first=Kees |year=2010 |title=Perseverance of pikas in the Miocene: interplay of climate and competition in the evolution of Spanish Ochotonidae (Lagomorpha, Mammalia) |journal=Geologica Ultraiectina |volume=333 |publisher=Departement Aardwetenschappen |isbn=978-90-5744-194-3 |quote=document type Dissertation [http://dspace.library.uu.nl/bitstream/handle/1874/197550/hordijk.pdf?sequence=1 full text] |hdl=1874/197550 }}</ref>

}}

==Additional references of the Paleobiology Database==
{{Reflist |group=pdb |30em|refs=

<!-- references for map - start -->

<ref name="Barnosky88">{{cite journal |last1=Barnosky |first1=A. D. |last2=Rasmussen |first2=D. L. |date=1988 |title=Middle Pleistocene arvicoline rodents and environmental change at 2900-meters elevation, Porcupine Cave, South Park, Colorado|journal=Annals of Carnegie Museum |volume=57 |issue=12 |pages=267–292 |doi=10.5962/p.330577 |doi-access=free }}</ref>

<ref name="Belyaeva48">{{cite book |last=Belyaeva |first=E. I. |date=1948 |title=Catalogue of Tertiary Fossil Sites of the Land Mammals in the U.S.S.R. }}</ref>

<ref name="Bonifay73">{{cite journal |last=Bonifay |first=M. F. |date=1973 |title=Principaux gisements paléontologiques Français du Pléistocene Moyen: Essai de classification |journal=Le Quaternaire |pages=41–50 }}</ref>

<ref name="Cai87">{{cite journal |last=Cai |first=B. |date=1987 |title=A preliminary report on the Late Pliocene Micromammalian fauna from Yangyuan and Yuxian, Hebei |journal=Vertebrata PalAsiatica |volume=25 |issue=2 |pages=124–136 }}</ref>

<ref name="Deng11">{{cite journal |date=2011 |title=Out of Tibet: Pliocene woolly rhino suggests high-plateau origin of Ice Age megaherbivores |journal=Science |volume=333 |issue=6047 |pages=1285–1288 |doi=10.1126/science.1206594 |pmid=21885780|last1=Deng |first1=T. |last2=Wang |first2=X. |last3=Fortelius |first3=M. |last4=Li |first4=Q. |last5=Wang |first5=Y. |last6=Tseng |first6=Z. J. |last7=Takeuchi |first7=G. T. |last8=Saylor |first8=J. E. |last9=Säilä |first9=L. K. |last10=Xie |first10=G. |bibcode=2011Sci...333.1285D |s2cid=8913866 }}</ref>

<ref name="Erbaeva86">{{cite journal |last=Erbaeva |first=M. A. |date=1986 |title=The Late Cenozoic Faunistic complexes of Transbaikalia with special reference to the micromammalia |journal=Quatärpaläontologie |volume=6 |pages=25–28 }}</ref>

<ref name="Frazier97">{{cite journal |last=Frazier |first=M. K. |date=1977 |title=New Records of Neofiber leonardi (Rodentia: Cricetidae) and the Paleoecology of the Genus |journal=Journal of Mammalogy |volume=58 |issue=3 |pages=368–373 |doi=10.2307/1379335|jstor=1379335  }}</ref>

<ref name="Gidley13">{{cite journal |last=Gidley |first=J. W. |date=1913 |title=Preliminary report on a recently discovered Pleistocene cave deposit near Cumberland, Maryland |journal=Proceedings of the United States National Museum |volume=46 |issue=2014 |pages=93–102 |doi=10.5479/si.00963801.46-2014.93|hdl=2027/hvd.32044107347718 |url=https://www.biodiversitylibrary.org/part/34077 }}</ref>

<ref name="Grady00">{{cite journal |last1=Grady |first1=F. |last2=Garton |first2=E. R. |date=2000 |title=Paleontology and historic field trip of the John Guilday Cave Preserve (Trout Rock) |journal=Bulletin – West Virginia Speleological Survey |volume=14 |pages=241–244 }}</ref>

<ref name="Guilday79">{{cite journal |last=Guilday |first=J. E. |date=1979 |title=Eastern North American Pleistocene ''Ochotona'' (Lagomorpha: Mammalia). Carnegie Museum of Natural History |journal=Annals of Carnegie Museum |volume=48 |issue=24 |doi=10.5962/p.330836 |s2cid=251525193 |doi-access=free }}</ref>

<ref name="Harington78">{{cite journal |last=Harington |first=C. R. |date=1978 |title=Quaternary vertebrate faunas of Canada and Alaska and their suggested chronological sequence|journal=Syllogeus |volume=15 }}</ref>

<ref name="Harington90">{{cite journal |last=Harington |first=C. R. |date=1990 |title=Vertebrates of the last interglaciation in Canada: A review|journal=Geographie Physique et Quaternaire |volume=44 |issue=3 |doi=10.7202/032837ar |page=375|url=http://www.erudit.org/fr/revues/gpq/1990-v44-n3-gpq1935/032837ar.pdf |doi-access=free }}</ref>

<ref name="Janossy70">{{cite journal |last=Janossy |first=D. |date=1970 |title=Ein neuer Eomyide (Rodentia, Mammalia) aus dem Ältestpleistozän ("Oberes Villafrankium", Villanyium) des Osztramos (Nordostungarn); (A new Eomyid (Rodentia, Mammalia) from the lowermost Pleistocene (upper Villafranchian) from Osztramos mountain (Northeastern Hungary) |journal=Annales Historico-Naturales Musei Nationalis Hungarici |volume=62 |pages=99–113 }}</ref>

<ref name="Janossy86">{{cite book |last=Janossy |first=D. |date=1986 |title=Pleistocene vertebrate faunas of Hungary |journal=Developments in Palaeontology and Stratigraphy |publisher=Elsevier |location=Amsterdam |volume=8 |isbn=978-0-444-99526-1}}</ref>

<ref name="Jopling81">{{cite journal |author=Jopling, A. V. |date=1981 |title=Stratigraphic, Sedimentological and Faunal Evidence for the Occurrence of Pre-Sangamonian Artefacts in Northern Yukon|journal=Arctic |volume=34 |issue=1 |display-authors=etal |doi=10.14430/arctic2499|doi-access=free }}</ref>

<ref name="Kurten80">{{cite book |last1=Kurten |first1=B. |last2=Anderson |first2=E. |date=1980 |title=Pleistocene mammals of North America |publisher=Columbia University Press |isbn=978-0-231-03733-4 }}</ref>

<ref name="Mead96">{{cite journal |last1=Mead |first1=J. I. |last2=Grady |first2=F. |date=1996 |title= ''Ochotona'' (Lagomorpha) from late Quaternary cave deposits in eastern North America|journal=Quaternary Research |volume=45 |issue=1 |pages=93–101 |doi=10.1006/qres.1996.0009|bibcode=1996QuRes..45...93M |s2cid=128811270 }}</ref>

<ref name="Qiu87">{{cite journal |last=Qiu |first=Z. |date=1987 |title=Neogene micromammals of China |journal=Whyte, P., ed. Paleoenvironment of East Asia from the Mid-Tertiary, Second International Conference on the Paleoenvironment of East Asia |volume=77 |issue=1–2 |pages=834–848 }}</ref>

<ref name="Rasmussen74">{{cite journal |last=Rasmussen |first=D. L. |date=1974 |title=New Quaternary mammal localities in the upper Clark Fork River valley, western Montana |journal=Northwest Geology |volume=3 |pages=62–70 }}</ref>

<ref name="Sotnikova97">{{cite journal |last1=Sotnikova |first1=M.V. |last2=Dodonov |first2=A.E. |last3=Pen'kov |first3=A.V. |date=1997 |title=Upper Cenozoic bio-magnetic stratigraphy of Central Asian mammalian localities |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=133 |issue=3–4 |pages=243–258 |doi=10.1016/s0031-0182(97)00078-3|bibcode=1997PPP...133..243S }}</ref>

<ref name="Terzea96">{{cite journal |last=Terzea |first=E. |date=1996 |title=Biochronology of the Pleistocene deposits at Betfia (Bihor, Romania) |journal=Acta Zoologica Cracoviensia |volume=39 |issue=1 |pages=531–540 }}</ref>

<ref name="Winkler90">{{cite journal |last1=Winkler |first1=A. J. |last2=Grady |first2=F. |date=1990 |title=The middle Pleistocene rodent ''Atopomys'' (Cricetidae: Arvicolinae) from the eastern and south-central United States |journal=Journal of Vertebrate Paleontology |volume=10 |issue=4 | doi = 10.1080/02724634.1990.10011831 |pages=484–490|bibcode=1990JVPal..10..484W }}</ref>

<ref name="PaleoDBO2">Additional contributors to utilized records of Paleobiology Database (authorizers supplying these records) include John Alroy, Anna Behrensmeyer, Will Clyde, Alan Turner, Mark Uhen.</ref>

<!-- references for map - end -->

<ref name="Shotwell56">{{cite journal |last=Shotwell |first=J. A. |date=1956 |title=Hemphillian mammalian assemblage from Northeastern Oregon|journal=Geological Society of America Bulletin  |volume=67 |issue=6 |doi=10.1130/0016-7606(1956)67[717:hmafno]2.0.co;2 |page=717|bibcode=1956GSAB...67..717S }}</ref>

<ref name="Voorhies90">{{cite book |last=Voorhies |first=M. R. |editor-last=Gustavson |editor-first=T. C. |title=Bureau of Economic Geology Guidebook |date=1990 }}</ref>

<ref name="PaleoDBOspan2">Additional contributors to utilized records of Paleobiology Database (authorizers supplying these records) include John Alroy.</ref>

<ref name="Guthrie71">{{cite journal |last1=Guthrie |first1=R. D. | last2=Matthews | first2=J. V. Jr. |date=1971 |title=The Cape Deceit fauna—Early pleistocene mammalian assemblage from the Alaskan arctic|journal=Quaternary Research |volume=1 |issue=4 |doi=10.1016/0033-5894(71)90060-3 |pages=474–510|bibcode=1971QuRes...1..474G |s2cid=86601856 }}</ref>

<ref name="Storer04">{{cite journal |last=Storer |first=J. E. |date=2004 |title=A Middle Pleistocene (late Irvingtonian) mammalian fauna from Thistle Creek, Klondike Goldfields region of Yukon Territory, Canada |journal=Paludicola |volume=4 |issue=4 |pages=137–150 }}</ref>

<ref name="Tedford09">{{cite journal |last1=Tedford |first1=R. H. |last2=Wang |first2=X |last3=Taylor |first3=B. E. |date=2009 |title=Phylogenetic Systematics of the North American Fossil Caninae (Carnivora: Canidae) |journal=Bulletin of the American Museum of Natural History |volume=325 |pages=1–218|doi=10.1206/574.1|hdl=2246/5999 |s2cid=83594819 |hdl-access=free }}</ref>

<ref name="PaleoDBOwhar2">Additional contributors to utilized records of Paleobiology Database (authorizers supplying these records) include John Alroy, Jonathan Marcot.</ref>

}}

==Further reading==
*{{cite book |title=The Little-known Pika |first1=Robert Thomas |last1=Orr |edition=illustrated |location=New York |publisher=Macmillan|year=1977 |isbn=978-0-02-593960-8}}

==External links==
{{Commons category|Ochotona}}
{{Wikispecies|Ochotona}}
* [http://cmiae.org/national-park-feature-article/the-trek-of-the-pika/ The trek of the pika], by Michael Morris, Parks Canada, Mount Revelstoke and Glacier National Parks. (includes sound file)

{{Lagomorpha|O.}}
{{Lagomorpha Genera|La.|state=collapsed}}
{{Taxonbar|from1=Q184067|from2=Q4364126}}
{{Authority control}}

[[Category:Extant Burdigalian first appearances]]
[[Category:Pikas| ]]
[[Category:Taxa named by Johann Heinrich Friedrich Link]]