Little pocket mouse
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California subspecies of the small pocket mouse ( Perognathus longimembris pacificus ) |
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| Perognathus longimembris | ||||||||||||
| ( Coues , 1875) |
The small pocket mouse ( Perognathus longimembris ) is a rodent (Rodentia) from the family of pocket mice (Heteromyidae) living in North America .
features
The soft, silky and bristle-free fur of the little pocket mouse is brown on the upper side of the body and whitish on the belly. The average dimensions of adult animals are: body length 56.7 mm, tail length 70.2 mm, hind foot length 16.2 mm and ear length 6.3 mm. The average body weight of the adult animals is 7 to 9 g. The soles of the hind feet are hairy.
distribution and habitat
The small pocket mouse occurs with several subspecies in the southwest of the USA and in the western coastal regions of Mexico . She prefers to inhabit desert and steppe areas there and is classified by the World Conservation Organization IUCN as " Least Concern = not endangered". The only exception is the subspecies Perognathus longimembris pacificus , which lives in a limited area in California and is classified as " Critically Imperiled ".
Way of life
The little pocket mouse lives in underground burrows, preferably under bushes. It is nocturnal and has a short period of activity in the first two hours after sunset and then sporadically for the rest of the night. It is largely inactive in winter depending on the outside temperature and reaches its most active phase in June and July. It feeds on seeds, plant matter and small invertebrates. Some of the food is transported into the building in their cheek pouches and stored there. It covers its fluid requirements exclusively through food and does not need drinking water. This was also the reason that this species was selected for space tests. The main breeding season extends from March to May. A litter is two to eight young animals. Usually a female only gives birth once a year. Predators include owls (Strigiformes) and snakes (Serpentes), as well as various carnivorous mammals including the southern grasshopper mouse .
Use of the mice in space
Five little pocket mice, named Fe, Fi, Fo, Fum, and Phooey , traveled aboard the Apollo 17 capsule to the moon in December 1972 , orbiting it 75 times. The effect of cosmic rays on living things was to be investigated in the mice . Four of the mice survived the trip. Subsequent investigations essentially yielded the following results: A small lesion in the scalp, which could be regarded as an indication of the susceptibility to particles of cosmic rays, but this problem must be investigated further. However, the absence of detectable lesions in the brain itself leaves the degree of susceptibility of the brain tissue to this radiation source unresolved. The causes for the damage to the olfactory organs and the reason for the increased exudation in the middle ear cavities also remain undetermined .
In July 1973, more pocket mice were brought into orbit with the Skylab 3 space station . The aim of this experiment was to investigate the circadian rhythm of a mammal during space travel. In particular, the aim was to find out whether the body temperature and the movements of the pocket mouse are influenced under conditions of prolonged weightlessness. As the animals died 30 hours after the start of the mission due to a power failure, no meaningful information could be obtained.
Individual evidence
- ^ San Berardino County Museum: Little Pocket Mouse (Perognathus longimembris). Retrieved January 7, 2021 .
- ↑ Little Pocket Mouse (Perognathus longimembris). In: ecotox.oehha.ca.gov. Retrieved February 5, 2021 .
- ^ IUCN Red List for Perognathus longimembris
- ↑ NatureServe Explorer for Perognathus longimembris pacificus
- ↑ California Animal Facts - Little Pocket Mouse
- ^ Webb Haymaker, Bonne C. Look, Eugene V. Benton, Richard C. Simmonds: The Apollo 17 Pocket Mouse Experiment (BIOCORE). In: SP-368 Biomedical Results of Apollo. NASA, accessed January 7, 2021 .
- ^ NASA: Chronobiology of Pocket Mice (S071). In: Life Sciences Data Archive. Retrieved January 7, 2021 .
- ↑ Spacefacts: Skylab August 3, 11, 2020, accessed on January 7, 2021 (English): "Both experiments were unsuccessful due to a power failure 30 hours after launch, which killed the animals"
literature
- Ronald M. Nowak: Walker's Mammals of the World. 2 volumes. 6th edition, Johns Hopkins University Press, Baltimore / London, 1999, ISBN 0-8018-5789-9 .
Web links
- Biological Diversity - Information on the Pacific Pocket Mouse
- ITIS report - taxonomy