American pika
| American pika | ||||||||||||
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American pika ( Ochotona princeps ) |
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| Scientific name | ||||||||||||
| Ochotona princeps | ||||||||||||
| ( Richardson , 1828) |
The American Pfeifhase ( Ochotona princeps ) is a species of mammal from the family of the Pfeifhasen within the hare-like . Their distribution area is in western North America and extends from southwest Canada over large parts of the western United States .
features
general characteristics
The American pika reaches a body length of 16.2 to 21.6 centimeters and is one of the medium-sized representatives of the genus. The body weight is 121 to 176 grams. In some areas the males are slightly larger than the females, but this sexual dimorphism is not very pronounced. The body is egg-shaped with short ears, a very short and usually invisible tail, and short legs. The body color varies and changes seasonally. In summer the back color is gray to cinnamon brown. In winter the fur is about twice as long and gray. The belly side has a light to whitish color regardless of the season, but in contrast to the Alaskan Pika ( Ochotona collaris ) it is not completely white. The round ears are covered with dark hair on the inside as well as on the outside and have a white border. The vibrissae are comparatively long at 40 to 77 millimeters. The front legs have five fingers, the hind legs only four. The paws are hairy with the exception of small black toe pads.
Both the females and the males have a pseudokloake as a common exit of the intestine and the ureters as well as the genital organs. The penis and clitoris are located in this pseudocloake and can be turned out. The females have six mammary glands that do not enlarge during breastfeeding ( lactation ).
Features of the skull
The skull of the American pika is approximately round with a flat and wide region between the eyes (intraorbital region). The muzzle is slender, the nostrils are largest in the front area and the upper jaw (maxilla) has a large window . The zygomatic bone is elongated and forms a prominent protrusion on the posterior zygomatic arch .
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The dentition corresponds to the typical whistle-hare bite with two incisors , three premolar teeth and two molars in the upper jaw as well as only one incisor, two premolar teeth and three molars in the lower jaw. Canine teeth are generally not developed in rabbits.
Physiological characteristics
The American pika has a high body temperature of 40.1 ° C on average, a body temperature of 43.1 ° C on average is fatal (lethal temperature). The metabolic rate is very high with 1.53 cm 3 of oxygen per hour, thermoregulation is mainly carried out by animal behavior and less physiological.
distribution
The distribution area of the American pika is in western North America and extends from Alberta and British Columbia in southern Canada over much of the western United States to New Mexico , Utah , Nevada and California .
Way of life
The American pika is diurnal and spends about 30 percent of the time above the earth. This time is spent ingesting food, gathering food, communicating with other pika and territorial behavior. In autumn and winter the animals spend more time in their burrows and are less active.
They are territorial and occupy and defend their territories against other whistles. The females live further apart than the males who have to fight for and defend their territories. The chances of survival of a young animal are directly dependent on the possibility of conquering and maintaining a territory. The territories are defended by persecutions and aggressive territorial fights, with clashes mainly between animals of the same sex and animals without partners. The partner bond is monogamous and takes place between animals of different sexes in neighboring territories. The animals tolerate each other more than other animals and communicate with each other in the form of short whistling duets. Accordingly, the distances between the territories with mating animals are smaller than the animals of the same sex to compete.
The pika does not dig its own buildings, but looks for protection in the gaps in the rubble of its living space. In winter, however, he digs tunnels in the snow to get to the vegetation below.
nutrition
The American pika is a generalist herbivore. It feeds accordingly on all available plants in its habitat. The selection is based on the nutritional value - accordingly, the animals prefer plants with a high content of proteins and fats and a high water content. In summer, 78 to 87% of the whistle hares feed on short mountain grasses, perennials and shrubs, while avens , clover and sedges make up the rest. Poisonous plants are avoided, but can be collected as a supply in the buildings and eaten in winter when the toxins have broken down.
During the summer, a supply of long grasses and herbs is created, with up to 30 species of plants to be found in the buildings. The collection points are set up in the area of the transition from the scree to the pasture areas and serve as territory boundaries. In winter, the collected supplies are taken into the burrow and serve as main food, supplemented by lichens and other plants.
Like other hare-like species, the American pigeon hares are caecotrophic , so the main digestion of food only takes place behind the stomach in the large appendix . They accordingly produce two different types of fecal pills, one soft and light and the other dark and hard. The soft, not yet completely digested fecal pills are eaten a second time and only then release a large part of the nutrients they contain. Without resuming the fecal pills, only about 68% of the nutrients would be absorbed.
Reproduction
The American pika is monogamous , with neighboring animals of different sexes forming pairs. If several males are available, the choice of mate is made by the females.
Mating begins about a month before the snow melts and the gestation period lasts about 30 days; ovulation in these animals is triggered by mating. In the lowlands, the birth takes place around March, in higher altitudes only in April to June. The females usually give birth twice a year and give birth to an average of three young each. The young animals have a birth weight of 10 to 12 grams and are breastfed for about 28 days. The lactation consumes a lot of the fat reserves of the females and they usually only take care of the second litter if the first has not survived. The young are blind and only slightly hairy at birth, but the teeth are completely present. The eyes open after about nine days. The dams spend most of the time in search of food and come to breastfeed the young about every two hours for ten minutes. After about four weeks the young animals become independent and they reach the size of the old animals after about three months.
The whistling hares reach sexual maturity after about a year, then the first mating takes place. The maximum age the American pika can reach in the wild and in captivity is about seven years. However, due to the high mortality rate , the animals only live an average of three years in the wild.
Predators and parasites
The predators and birds of prey of the American pika belong to the predators . The smaller predators that pigeon hares prey on include the long-tailed weasel ( Mustela frenata ) and the ermine ( Mustela erminea ). Larger predators are coyotes ( Canis latrans ) and spruce marten ( Martes americana ); they mainly hunt young animals that are not yet fast enough to escape. The golden eagle ( Aquila chrysaetos ) also hunts the American pika, but its influence on the population is small.
The pigeon hares are protected above all by the moderate camouflage color of their fur, which makes it difficult to discover them in the scree. When a predator is sighted, the animals utter alarm calls to warn the other whistling hares. However, the smaller predators in particular are able to capture the fleeing pigeon hares in their hiding places.
The American pika is also colonized by numerous parasites - especially endoparasites in the intestines. This includes numerous types of Eimeria . When it comes to ectoparasites , the pika harbors primarily fleas .
Systematics
The first description of the American pigeon comes from the American naturalist John Richardson in 1828.
The American Pfeifhase was assigned as a separate species to the Pfeifhasen (genus Ochotona ) and the subgenus Pika . Numerous subspecies were described, five of which are currently recognized.
Hazard and protection
The species is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as not endangered (least concern) due to its very large distribution area and large population.
supporting documents
- ↑ a b c d e f g h i j k l m n o p Alexandra Peri: Ochotona princeps in the Animal Diversity Net. Retrieved July 3, 2012.
- ↑ a b c d e f g h i j k Arthur T. West, Marla L. Weston: Ochotona princeps . In: Mammalian Species . tape 352 , 1990, pp. 1–8 ( full text [PDF; 1000 kB ]). Full text ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b c d Joseph A. Chapman, John EC Flux (Ed.): Rabbits, Hares and Pikas. Status Survey and Conservation Action Plan. (PDF; 11.3 MB) International Union for Conservation of Nature and Natural Resources (IUCN), Gland 1990; Pp. 43-46. ISBN 2-8317-0019-1 .
- ↑ a b Ochotona princeps in the endangered Red List species the IUCN 2011. Posted by: E. Bewer, AT Smith, 2008. Accessed July 3, 2012th
- ↑ Don E. Wilson & DeeAnn M. Reeder (eds.): Ochotona princeps ( Memento of the original from March 25, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. in Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed).
literature
- Joseph A. Chapman, John EC Flux (Eds.): Rabbits, Hares and Pikas. Status Survey and Conservation Action Plan. (PDF; 11.3 MB) International Union for Conservation of Nature and Natural Resources (IUCN), Gland 1990; Pp. 43-46. ISBN 2-8317-0019-1 .
- Arthur T. West, Marla L. Weston: Ochotona princeps . In: Mammalian Species . tape 352 , 1990, pp. 1–8 ( full text [PDF; 1000 kB ]).
Web links
- Ochotona princeps in the endangered Red List species the IUCN 2011. Posted by: E. Bewer, AT Smith, 2008. Accessed July 3, 2012th
- Alexandra Peri: Ochotona princeps in the Animal Diversity Net. Retrieved July 3, 2012.