Dryland dwarf bag rat
| Dryland dwarf bag rat | ||||||||||||
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| Scientific name | ||||||||||||
| Marmosa xerophila | ||||||||||||
| Handley & Gordon , 1997 |
The dryland pygmy bag-rat ( Marmosa xerophila ) is a species of marsupial that occurs on the coasts of the Gulf of Venezuela between the La Guajira department in the extreme northeast of Colombia and the Paraguaná peninsula in northwest Venezuela.
description
The animals reach a head trunk length of 10.5 to 15.9 (males) or 10.1 to 13.3 cm (females), have a length of 14.4 to 18.1 (males) or 13 to 16.7 cm (Females) long tail and reach a weight of 40 to 87 (males) and 29 to 57 g (females). The tail is thus on average around 20% longer than the head and torso combined. The fur on the back and the top of the head are light yellow, sand-colored or light gray-brown. The sides of the body are lighter. The middle of the snout is lighter than the top of the head, contrasts clearly with this. There are narrow dark brown circles around the black eyes that do not reach the bases of the ears. The fur on the underside is yellowish or whitish. The paws are whitish. The 10% of the tail, which is close to the body, is hairy, the rest is hairless. The bare tail section is gray-brown and the underside is lighter than the top. Females do not have a pouch. The number of teats is eleven, five on each side and one in the middle. The karyotype is unknown.
Habitat and way of life
The coastal region of the Gulf of Venezuela is not influenced by the northeast trade winds and therefore has a dry, semi-arid climate . It is passed with a thorny bush vegetation. The annual average temperature is 24 ° C and the annual rainfall is between 250 and 500 mm. Most of the specimens of the dryland pygmy sac rat were caught in thorn bushes. All sites are below 100 meters above sea level.
The dryland dwarf sacred rat feeds primarily on insects, with beetles being the most important source of animal food with a share of more than 50%. In addition, Hymenoptera , arachnids , grasshoppers , other insects and insect larvae eaten. The vegetable food that is consumed includes parts of the cacti Stenocereus griseus and Cereus aff. repandus . The animals are probably nocturnal and live both on the ground and climbing in the vegetation. The population density varies from 620 animals per km² at the end of the dry season to 2000 specimens per km² in January in the middle of the rainy season. The territory used by an individual is between 0.06 and 0.13 hectares.
Most females give birth in the dry season, when the fruits of the cacti are ripe and beetles and their larvae are particularly numerous. The gestation period is about two weeks and the litter size is three to a maximum of 13. The young are about 6 to 7 mm long at birth. The young animals are initially firmly attached to a teat and are carried around by the mother animal during all of its activities. After about 23 days they separate from the teats for the first time and remain in the nest for another week. The coat is fully developed at around 36 days of age. The young animals open their eyes at around 40 days of age and then begin to leave the nest together with their mother or alone. They are weaned around 60 days of age. Most females give birth only once a year, some give birth twice and very few give birth three times. Females reach sexual maturity at nine months of age.
status
The dryland dwarf bag rat is listed as Endangered by the IUCN . Their distribution area is less than 20,000 km² and large parts of the area are now used for agriculture.
supporting documents
- ↑ a b c d e f Diego Astúa: Family Didelphidae (Opossums). in Don E. Wilson , Russell A. Mittermeier : Handbook of the Mammals of the World - Volume 5. Monotremes and Marsupials. Lynx Editions, 2015, ISBN 978-84-96553-99-6 . Page 138.
- ↑ Marmosa xerophila in the endangered Red List species the IUCN 2016 Posted by: Perez-Hernandez, R., López Fuster, M. & Ventura, J., 2015. Retrieved on February 20 of 2019.