Ganzu pikas ( (Lagomorph Specialist Group, 1996)) are endemic to China and are located in the Ganzu, Qinghai, and Sichuan provinces.
Ganzu pikas inhabit alpine shrub habitats, which are part of steppe-meadow environments. Ganzu pikas live in alpine areas where temperatures fall below freezing even during summer nights, with elevations ranging from 2000 to 4000 m (Kenagy and Zheng, 2006). Ganzu pikas are mainly found in shrubby cinquefoil (Dasiphora fruticosa), but avoid dense shrub areas, preferring areas slightly open such as natural mounds created by zokors (Myospalax). These mounds are used to avoid predators, allowing the pikas to see easier and having escape nearby (Jiang and Wang 1991). (Jiang and Wang, 1991; Kenagy and Zheng, 2006)
- Terrestrial Biomes
- savanna or grassland
- Range elevation
- 2000 to 4000 m
- 6561.68 to 13123.36 ft
The physical morphology of Ganzu pikas is similar to that of Moupin pikas (Ochotona thibetana), and they can be confused in the field. However, Changlin et. al. 1997 suggests that the two species can be identified by the zygomatic arch. Ganzu pikas have narrower zygomatic arches than Moupin pikas. (Changlin, et al., 1997)
- Sexual Dimorphism
- sexes alike
The mating system of Ganzu pikas includes monogamy, polygyny, polyandry, and promiscuous systems. Jiang and Wang, 1991 indicate that Ganzu pikas exhibited a facultative monogamy mating system. Polygynous situations may be common considering the non-uniform distribution of high-quality habitats, male emancipation from parental care, and asynchrony of female estrus. (Jiang and Wang, 1991)
Ganzu pikas breed from April to August. They have a gestation period of about 20 days, and a lactation period of about 18 days. The litter size can be anywhere from 3 to 6 young. Ganzu pikas can breed at least 3 times per year, resulting in 9 to 18 young per year. The young are altricial and emerge from the burrow about 10 days after birth. Subadults (pika less than 1 year old) can and have been observed breeding. Males do not care for the young, even in monogamous pairs. (Jiang and Wang, 1991)
Nests are constructed 2 to 3 hours before parturition, with a size of 15 cm, consisting of dry grass and hair of yak and sheep. Once the babies are born the mother does not come back to the nest except to nurse. (Jiang and Wang, 1991)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- post-partum estrous
- Breeding interval
- Ganzu pikas can breed at least 3 times per year.
- Breeding season
- Breeding occurs from April to August.
- Range number of offspring
- 3 to 6
- Average gestation period
- 20 days
- Average weaning age
- 18 days
- Average age at sexual or reproductive maturity (female)
- 1 years
- Average age at sexual or reproductive maturity (male)
- 1 years
Males rarely care for the young. Mother-offspring relationships resemble those of other medium-sized lagomorphs. Nursing is "scheduled" and the mother and her young remain separate except during the nursing period. The mother nurses young about 3 to 5 times a day. Infrequent contact between the mother and her young may promote dispersal and is perhaps related to the solitary habit of Ganzu pikas. The length of time taken to nurse is positively related to littler size. These pikas have only two teats, therefore the mother must stay longer with the babies ensuring that all young receive milk. (Jiang and Wang, 1991)
- Parental Investment
No information on longevity of Ganzu pikas was found in the literature. Most pikas live for only a few years, with high first year mortality rates.
Social organization in Ganzu pikas is divided into four phases. First litter emergence defines the spring phase (March to May). In this phase home ranges for males expand (1233.09 m^2) and female home ranges stay mainly stable (519.94 m^2).
The family phase is from May to August and is characterized by the existence of family structure caused by the philopatry of young within the home ranges of their parents. Once the young are weaned, they live near their natal burrow and gradually begin to disperse. At this time, the mother abandons the area and seldom encounters the young. During this phase both males and females expand the size of their home ranges.
In the rearrangement phase, from August to September, there is rapid juvenile and subadult dispersal, the family structure during the reproductive period breaks down, and pairs form between males and females. During this time, female home ranges are stable, but subadult males become wanderers.
In winter, or stable, phases, both male and female home ranges shrink (male 772.13 m^2, females 458.56 m^2). Overlap between male and female home ranges is increased, creating a pair-bond that is likely to last until the spring phase of the next year and ensures mating. (Jiang and Wang, 1991)
Ganzu pikas exhibit allogrooming, grooming each other in the area of their head and ears, areas where ectoparasites may be concentrated. Allogrooming is usually brief and therefore only a ritualized friendly pattern not serving to clean the pelage. (Jiang and Wang, 1991)
Ganzu pikas have the habit of defecating at a latrine site. Defecation takes place in open areas, such as a small mound, presumably because the sites were suitable for digging faces pits. Males were observed defecating anywhere from 2-10 pellets at a time. (Jiang and Wang, 1991)
- Range territory size
- 519.94 to 4000.52 m^2
The home range of Ganzu pikas is variable over the course of one year. During different phases of life, home range changes are related to breeding periods. Home ranges are marked by either cheek rubbing or anal rubbing. Males were observed in aggressive postures when encountered by other males on the outer most areas of home ranges. (Jiang and Wang, 1991)
Communication and Perception
Ganzu pikas use their vision to remain vigilant for predators. When two littermates are together they often display body contact or play. When two males come close enough to be seen, the two males will often display warning postures and then chase or retreat into respective territories (Jiang and Wang 1991). (Jiang and Wang, 1991)
Like many other pikas (Ochotona), Ganzu pikas make frequent, sharp calls. There were 4 types of called identified:
- Long calls are used only by males and last about 8 seconds. Other males ignored the male that was giving the call. It is speculated that this is a breeding call because it is used during the breeding season.
- Short calls are used by both sexes and sound like "kit". They are used as a predator warning call. Neighboring pikas respond strongly to the call, fleeing to cover or burrows. Short calls probably play important role in intra-population contact as well.
- Trills are used by both sexes. They sound like "ki-ki", and occur at dusk and dawn. This call immediately triggers responses from other Ganzu pikas, and are often intermingled with short calls as well.
- Whines consisted of 1 to 3 weak "ku-ku" calls. The caller was usually near the natal burrow. This call is believed to communicate anxiety in young pika and functions as mother-infant contact. When the call was heard by the mother, she went to her young and began to nurse them. (Jiang and Wang, 1991)
Ganzu pikas, like other mammals, also use chemical cues extensively in communicating. Important forms of chemical communication are:
- Cheek rubbing, which is seen only in males during the breeding season. The areas that were rubbed were areas that overlapped parts of another males home range.
- Anus rubbing, also seen only in males during breeding season, it is thought to be a form of territorial marking, occuring when males are defecating.
- Nasal-nasal or oral-nasal contact. This usually occurred when two individuals encountered each other. This behavior may be important for the two individuals to become familiar with each other’s odor and identity. This behavior is indicative of a intimate relationship between two individuals. (Jiang and Wang, 1991)
Ganzu pikas, like most pikas, are herbivorous, grazing on the grasses and herbaceous plants in their native communities.
- Plant Foods
- wood, bark, or stems
Through visual communication, Ganzu pikas are well adapted to predator evasion. Ganzu pikas remain vigilant, especially to aerial predators, and have a set of warning calls to alert others to danger. Warning calls trigger other pikas to respond with more warning calls, maximizing the efficiency of the transmission of danger signals. Buteo hemilasius, Falco cherrug, Mustela eversmanii, and Mustela altaica are the major predators of Ganzu pikas. (Jiang and Wang, 1991)
Ganzu pikas impact vegetation communities through their grazing and food storage. They may also be important prey for native predators in steppe ecosystems.
Economic Importance for Humans: Positive
Ganzu pikas are important members of their native ecosystems.
Economic Importance for Humans: Negative
There are no known adverse effects ofon humans.
To date, most systematic treatments of Ochotona have been based on morphological characteristics; however, morphology often exhibits phenotypic plasticity and convergent evolution. The goal of the Changlin et al. (1997) study was to clarify confusion concerning six species of Chinese pikas through mtDNA restriction-site analysis. Ganzu pikas are often included in Moupin pika species (Ochotona thibetana) because of similarities in pelage color, size, and shape of the skull. Mitochondrial DNA analysis determined that these were in fact two separate species. Changlin et al. (1997) suggest that evolutionary diversification of pikas might be influenced by historical episodes of geologic and climatic changes. During the early Pleistocene the Qinghai-Xizang (Tibet) Plateau was uplifted, which resulted in an ice age, and moutain formation. Northwestern China became drier due to the rain shadow effect caused by the plateau. Therefore, vegetation was significantly altered and isolation of habitats was frequent. All of these events provide good opportunity for diversification and specialization within the genus Ochotona. Recent geological studies show that an ice sheet did not cover the Qinghai-Xizang Plateau during the Quaternary Ice Age. Therefore, ancestral pikas may have been typical of arid, cold adapted steppes, but now are located in steppe, shrub, coniferous forests, and alpine rocks. This suggests that pikas responded to habitat shifts induced by continued uplift of the Qinghai-Xizang Plateau and glacial cycles from the late Pliocene to the Pleistocene through gradual adaptation to new habitats (Changlin et al., 1997).
Tanya Dewey (editor), Animal Diversity Web.
Ryan Byrnes (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
- bilateral symmetry
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
to jointly display, usually with sounds, at the same time as two or more other individuals of the same or different species
- active during the day, 2. lasting for one day.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
an animal that mainly eats leaves.
An animal that eats mainly plants or parts of plants.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
Having one mate at a time.
having the capacity to move from one place to another.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
having more than one female as a mate at one time
- scent marks
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- seasonal breeding
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- tropical savanna and grassland
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
Changlin, Z., S. Liming, Y. Ning. 1997. Variation in Mitochondrial DNA and Phylogeny of Six Species of Pikas (Ochotona). Journal of Mammalogy, Vol. 78, No. 2.: "387-396". Accessed November 20, 2006 at http://www.jstor.org/view/00222372/ap050315/05a00130/0?currentResult=00222372%2bap050315%2b05a00130%2b0%2cFF07&searchUrl=http%3A%2F%2Fwww.jstor.org%2Fsearch%2FBasicResults%3Fhp%3D25%26si%3D1%26Query%3Dochotona%2Bcansus.
Jiang, Y., Z. Wang. 1991. Behavior of Ochotona-Cansus Adaptation to the Alpine Environment. Shou lei xuebao = Acta theriologica Sinica, Volume 11/Issue: 1: "23-40".
Kenagy, J., X. Zheng. 2006. "Burke Museum of Natural History and Culture" (On-line). Mammals of Sichuan. Accessed November 02, 2006 at http://www.washington.edu/burkemuseum/collections/mammalogy/sichuan.html#lagomorpha.
Lagomorph Specialist Group, 1996. "IUCN 2006. 2006 IUCN Red List of Threatened Species" (On-line). Accessed November 10, 2006 at http://www.iucnredlist.org/search/details.php/41256/summ.