American harvest mice
| American harvest mice | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Baiomys | ||||||||||||
| True , 1894 |
The American harvest mice ( Baiomys ) are a genus of New World mice , which are the smallest rodents in North America . They have a head body length of 5 to 8 centimeters, plus 4 to 5 centimeters of tail. The weight is only 7 to 8 grams. The fur is brown on top and gray-white on the underside. In their homeland they are only known as harvest mice (“pygmy mice”), a name that in German usage would lead to confusion with the European harvest mouse , which is not related.
The distribution area extends from the southern edge of the USA via Mexico to Nicaragua . Here they live in semi-desert areas where they seek shelter from bushes. They are nourished by green parts of plants, and in small quantities they also eat seeds and insects.
American harvest mice can reproduce all year round. The gestation period is 20 days, after which 1 to 5 young are born. A captive female had given birth nine times in just 200 days. The young live in the wild in a nest made of dry parts of the plant, which is protected by a shrub or under a branch. Both parents take care of the offspring, who are largely independent at the age of 30 days. The lifespan of a harvest mouse was three years in captivity, but less in the wild.
A distinction is made between two types:
- Northern harvest mouse , Baiomys taylori , northern Mexico , Texas , Oklahoma , Arizona
- Southern harvest mouse , Baiomys musculus , southern Mexico to Nicaragua
The northern harvest mouse was not native to US territory until the 1950s, but has since expanded its range steadily northwards. It was first seen in New Mexico in the 1990s . It is believed that human change in the landscape through agriculture benefits animals.
Their closest relatives are the brown mice ( Scotinomys ), with whom they together form the genus group of Baiomyini within the Neotominae .
literature
- Ronald M. Nowak: Walker's Mammals of the World. 2 volumes. 6th edition. Johns Hopkins University Press, Baltimore MD et al. 1999, ISBN 0-8018-5789-9 .