Myotis vivesi
Myotis vivesi is a bat species from the family of Myotis bats ( Vespertilionidae ), which is native to Mexico and the only representative of the subgenus Pizonyx. She is known for her based on crustaceans and fish diet. The species name is derived from the Latin word " vivo " ( = live ) from.
Description
Myotis vivesi is with a total length of 145 mm and a forearm length of 62 mm, the largest representative of the mouse ears. Their appearance is similar to the Eurasian Great mouse ear, but however it has much bigger feet from an average of 23 mm in length. The feet are thus the same length as the tibia. They project from the airplane skin which starts only at the level of the knee. The ears protrude when placed further forward about 5 mm above the snout and typically include four grooves. The coat is grayish with a much lighter underside. The wings are long and slender at the tips, which is typical for bats flying in relatively open air space with only a few obstacles. The wings also have nodes with hematopoietic ( blood-forming ) cells, which is unique to mouse ears. The red blood cells of Myotis vivesi have a diameter of 4.6 microns, a normal size for mammals, while the blood cells of other mouse ears are about 6 microns in diameter.
Way of life
Myotis vivesi is known for its diet that is mainly based on fish and crustaceans. In fact, make crustaceans and not, as often assumed fish most of the food out. The extended feet and claws make it the ideal tool, similar to the Neotropical Great Hare mouth ( Noctilio leporinus ). Feet and tail wing membrane are pulled through the top layer of water in flight and the prey fished it. The echolocation calls of Myotis vivesi move between 20 and 45 kHz and are therefore partially audible to humans. Per second, the animals come from 10-20 calls, which condense and become higher as they make up at the water surface prey. During the day, Myotis vivesi hidden in crevices and caves. The same columns are often used by the dwarf petrel ( Halocyptena microsoma ) and the Black Petrel ( Oceanodroma melania ) used as a nesting site. These two birds benefit from the association with Myotis vivesi, since their presence apparently excludes large lizards prey on the eggs. It assumes, however, that Myotis vivesi only be staying in the same column if no other suitable resting places are available.
Since there usually are on the islands where Myotis vivesi found no other mammals, barn owls are (Tyto alba ) were the main predators of this type Other predators are birds such as the Louisiana shrike (Lanius ludovicianus ), the ring-billed gull (Larus delawarensis ), the Western Gull (Larus occidentalis), the common raven (Corvus corax), the peregrine falcon (Falco peregrinus) and the osprey (Pandion haliaetus). In addition, entrained predators such as the domestic cat (Felis silvestris catus) and the brown rat (Rattus norvegicus) are increasingly becoming a problem.
Reproduction
After a gestation period of 55-65 days the females in May or the first week of June each give birth to a single cub. The newborns weigh 5.9 to 6.6 g and are born with their eyes closed, but which open after birth already on the third day. The first three weeks after birth, the boys hanging at the teat of the mother, but are left on foraging flights of the females in the nursery. After 50 days, the young can fly autonomously and leave at night the hanging place.
Distribution and habitat
Myotis vivesi occurs in the coastal area and on most islands in the Gulf of California ( Mexico). There, the kind often looking for gaps in Felsabrutschungen, but is still found in caves and rock crevices. In case of faults she seeks protection at various points, so under flat stones or tortoise shells. The stock is classified by the IUCN due to its small distribution area as vulnerable ( "vulnerable "). The populations are declining and probably consist of a maximum of 15,000 individuals.