Nimble slim-pouch rat
| Nimble slim-pouch rat | ||||||||||||
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Nimble small-pouch rat ( Gracilinanus agilis ) |
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| Scientific name | ||||||||||||
| Gracilinanus agilis | ||||||||||||
| ( Burmeister , 1854) |
The nimble narrow-pouch rat ( Gracilinanus agilis ) occurs in central South America from northeast Brazil to the east of Bolivia and Peru.
description
The animals reach a head trunk length of 8.1 to 11.5 cm, have a 10.9 to 15.8 cm long tail and reach a weight of 15 to 40 g. The tail is usually 140% of the length of the head. Males grow larger, and the skulls of males and females differ in size and shape. The fur is long, dense and woolly. The back and head are covered with hair that has a gray base and orange tips, resulting in a brown to reddish color with a gray tinge. The transition to the lighter color of the sides of the body is fluid. The eyes are surrounded by dark circles, the cheeks are bright orange. The peritoneum is yellowish to cream-colored. The feet are whitish and the ears are light and large (more than 21 mm long). The tail is brown and lighter on top than on the underside. The females do not have a pouch. The number of teats is 13, six on each side and one in the middle. The karyotype of the nimble narrow-pouch rat consists of a chromosome set of 2n = 14 chromosomes (FN = 24).
Habitat and way of life
The nimble narrow-pouch rat occurs in Brazil in the northeast in the semi-arid caatinga and in the savannas of the cerrado , also in seasonally dry forests in eastern Paraguay, in eastern Bolivia and eastern Peru from sea level to altitudes of 1,800 meters. It is tree-dwelling, probably nocturnal, and feeds on insects, especially ants, termites and fruits. In addition to ants and termites, the remains of cockroaches , beetles , hymenoptera , two-winged birds , dust lice , mayflies , grasshoppers , beak peas and butterflies were found in fecal samples . In addition, spiders, snails, small vertebrates, especially young birds, and eggs are eaten from time to time. Fruits of Clidemia , Miconia and Ossaea from the family of melastomataceae of the nightshade family , Phoradendron , crushing bushes and passion flower eaten. In several studies, fruits made up almost 80% of the diet, the largest proportion ever found in opossum rats. Because of their water content, fruits are increasingly consumed during the dry season. The nimble narrow-pouch rat plays an important role in the spread of the seeds. Depending on the area, the nimble narrow-pouch rats breed at different times of the year, in the Cerrado z. B. in the rainy season, but in the Pantanal almost all year round. The median litter size appears to be ten pups, but only a small fraction of the pups grow old enough to reproduce. Only a small part of the males live long enough to be able to reproduce a second time (partial semelparity ), while a large part of the females survive the first breeding season.
Systematics
The author of the first description of the nimble narrow-pouch rat is the German natural scientist Hermann Burmeister , who described it in 1854 under the name Didelphis agilis and named Lagoa Santa in the Brazilian state of Minas Gerais as Terra typica . The species was later placed in the genus Marmosa . Due to differences in the structure of the skull and the teeth, the genus Gracilinanus was introduced in 1989 , to which the members of the Microtarsus group of the genus Marmosa and thus also the nimble narrow-pouch rat were placed.
status
The IUCN estimates the endangered status of the nimble narrow-pouch rat as safe ( Least Concern ). The area of distribution and population are large, the animals are found in various protected areas and they do not tolerate too much impairment of their habitat by humans.
supporting documents
- ↑ a b c d e 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 171.
- ↑ Gardner, AL & Creighton, GK 1989. A new generic name for Tate's (1933) Microtarsus group of South American mouse opossums (Marsupialia: Didelphidae). Proceedings of the Biological Society of Washington 102 (1): 3-7.
- ↑ gracilinanus agilis in the endangered Red List species the IUCN 2015 Posted by: Carmignotto, AP, Solari, S., de la Sancha, N. & Costa, L., 2015. Accessed January 25, 2020th