| Western mastiff bat | |
|---|---|
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Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Chiroptera |
| Family: | Molossidae |
| Genus: | Eumops |
| Species: | E. perotis |
| Binomial name | |
| Eumops perotis Schinz, 1821 | |
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| Geographic Range | |
Thewestern mastiff bat (Eumops perotis), also known as thewestern bonneted bat, thegreater mastiff bat, or thegreater bonneted bat, is a member of thefree-tailed bat family, Molossidae. It is found in theWestern United States,Mexico andSouth America. This species is the largest bat native toNorth America, and some of its distinguishing characteristics are its large ears, wings, and forearms.[2][3] The subspeciesEumops perotis californicus is aspecies of concern as identified by theU.S. Fish and Wildlife Service. The range of this subspecies is principally southwest desert regions of the United States, along the border with Mexico; however, the range extends as far north on the Pacific coast asAlameda County,California.[4]
The western mastiff bat is located in bothSouth America andNorth America. In South America, the species is found inBrazil and its neighboring countries, ranging southward to northernArgentina. It can also be found inCuba.[5] The subspecies in North America,Eumops perotis californicus, resides in the southwesternUnited States (California,Arizona,New Mexico,Texas) and ranges southward to parts of centralMexico.[6]
The greater mastiff bat prefers to live in habitats with open space. Some examples include desert scrub, woodlands, andgrasslands.[7] Roosts are commonly located in crevices of rocky areas, such as cliffs and canyons,[6] and have also been found within man-made structures such as buildings and tunnels.[7] As the western mastiff bat cannot take off from flat surfaces, these spots are at least 3 meters above ground, providing the bat with sufficient space to drop from and take flight.[6]
Eumops perotis is most notable for its size, as it is the largest North American bat. It has a body length of 6.2 to 7.2 in (16 to 18 cm)[8] and a wingspan of over 22 in (56 cm).[5] The body mass of this species can range from 60 to 70 g (2.1 to 2.5 oz).[8] The wings are long yet narrow, which limits the species' maneuverability in the air. The body mass of this species can range from 45 to 73 g (1.6 to 2.6 oz).[8] A defining characteristic is its large ears that range between 1.4 to 1.85 in (3.6 to 4.7 cm) and extend over the bat's snout. It also has large forearms with a length of 2.9 to 3.3 in (7.4 to 8.4 cm).[8] Males are larger than females and also have an odoriferous gland on their throat, which is less developed in females.[9] The western mastiff bat is mostly dark in color, as the body is primarily brown or gray, though the underside is a lighter color.[8]
Western mastiff bats arenocturnal, leaving roosts at night to find food.[6] Unlike most North American bats, they do not undergo either migration or prolongedhibernation, but are periodically active all winter.[2] The size of colonies varies, but they usually consist of less than 100 bats. Males and females live together yearly, even during maternity periods.[2]
The species is very active at night, spending 6–7 hours flying a night for a total distance of about 14.9 miles (24.0 km).[3] Its long, narrow wings allow the bat to maintain flight at high speeds for long periods of time. These bats can reach heights of 196 feet (60 m), though they are also observed flying closer to the ground.[9] One notable characteristic of this species is its high pitchedecholocation call, as it can be heard from heights of 990 feet (300 m).[6]
The western mastiff bat mainly feeds on smallinsects.Moths are its biggest food source, but it has been observed to eatbeetles,ants,dragonflies,crickets, andgrasshoppers.[5][9]
This species beginsmating in early spring and the offspring is born in the summer, usually by July.[9] Thegestation period is about 80–90 days, and females give birth to one offspring at a time, though twins are possible.[9] Theparturition period varies greatly. The young remain in a nursery after birth, with both the males and females.[9]
Though the western mastiff bat is listed under the Least Concern Category by theIUCN Red List of Threatened Species,Bat Conservation International reports that its numbers are decreasing in certain areas. One reason for its decline is its inability to find suitable water sites for drinking, as its size prevents it from drinking from small bodies of water.[10] Grazing and the use of pesticides have impacted foraging habitats.[2] The loss of cliff sites as a result of urban/suburban development and activities such as water impoundments, highway building, and quarry operations has also contributed to the species' endangered status, making it harder to find adequate roost places.[2]
Media related toEumops perotis at Wikimedia Commons
Data related toEumops perotis at Wikispecies