The western mastiff bat (''Eumops perotis''), also known as the western bonneted bat, the greater mastiff bat, or the greater bonneted bat, is a member of the
free-tailed bat
The Molossidae, or free-tailed bats, are a family of bats within the order Chiroptera.
The Molossidae is the fourth-largest family of bats, containing about 110 species as of 2012. They are generally quite robust, and consist of many strong-flyi ...
family, Molossidae. It is found in the
Western United States
The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the Wes ...
,
Mexico
Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...
and
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...
. This species is the largest bat native to
North America, and some of its distinguishing characteristics are its large ears, wings, and forearms.
The subspecies ''Eumops perotis californicus'' is a
species of concern as identified by the
U.S. Fish and Wildlife Service
The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...
. 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 as
Alameda County
Alameda County ( ) is a county located in the U.S. state of California. As of the 2020 census, the population was 1,682,353, making it the 7th-most populous county in the state and 21st most populous nationally. The county seat is Oakland. Alam ...
,
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...
.
[Steven Moore, ''Endangered Species Survey for Water Treatment Plant Number Two of the ]Alameda County Water District
The Alameda County Water District (ACWD) is a public agency in Alameda County, California, United States, which has responsibilities for managing and protecting certain groundwater resources within Alameda County. While most of the county is serv ...
'', Earth Metrics Inc., published by the Alameda County Water District, Report number 10445.003, October, 1990
Range and habitat
The western mastiff bat is located in both
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the souther ...
and
North America. In South America, the species is found in
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
and its neighboring countries, ranging southward to northern
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...
. It can also be found in
Cuba
Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribbea ...
.
The subspecies in North America, ''Eumops perotis californicus,'' resides in the southwestern
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...
(
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...
,
Arizona
Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a U.S. state, state in the Southwestern United States. It is the list of U.S. states and territories by area, 6th largest and the list of U.S. states and territories by population, 14 ...
,
New Mexico
)
, population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano)
, seat = Santa Fe, New Mexico, Santa Fe
, LargestCity = Albuquerque, New Mexico, Albuquerque
, LargestMetro = Albuquerque metropolitan area, Tiguex
, Offi ...
,
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...
) and ranges southward to parts of central
Mexico
Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...
.
The greater mastiff bat prefers to live in habitats with open space. Some examples include desert scrub, woodlands, and
grasslands.
Roosts are commonly located in crevices of rocky areas, such as cliffs and canyons,
and have also been found within man-made structures such as buildings and tunnels.
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.
Description
''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 (15.7 to 18.4 cm)
and a wingspan of over 22 in (56 cm).
The body mass of this species can range from .
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).
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 (7.3 to 8.3 cm).
Males are larger than females and also have an odoriferous gland on their throat, which is less developed in females.
The western mastiff bat is mostly dark in color, as the body is primarily brown or gray, though the underside is a lighter color.
Ecology and behavior
Western mastiff bats are
nocturnal
Nocturnality is an ethology, animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite.
Nocturnal creatures generally have ...
, leaving roosts at night to find food.
Unlike most North American bats, they do not undergo either migration or prolonged
hibernation, but are periodically active all winter.
The size of colonies varies, but they usually consist of less than 100 bats. Males and females live together yearly, even during maternity periods.
The species is very active at night, spending 6-7 hours flying a night for a total distance of about 14.9 miles (24 km).
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 (60m), though they are also observed flying closer to the ground.
One notable characteristic of this species is its high pitched
echolocation call, as it can be heard from heights of 990 feet (300m).
Diet
The western mastiff bat mainly feeds on small
insects
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...
.
Moths
Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of ...
are its biggest food source, but it has been observed to eat
beetles
Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, Elytron, elytra, distinguishing them from most other insects. The Coleoptera, wit ...
,
ants
Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Creta ...
,
dragonflies
A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threaten ...
,
crickets
Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 88 ...
, and
grasshoppers
Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago.
Grasshop ...
.
Reproduction
This species begins
mating
In biology, mating is the pairing of either opposite- sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. '' Copulation'' is the union of the sex organs of two sexually rep ...
in early spring and the offspring is born in the summer, usually by July.
The
gestation
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during preg ...
period is about 80-90 days, and females give birth to one offspring at a time, though twins are possible.
The
parturition
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...
period varies greatly. The young remain in a nursery after birth, with both the males and females.
Conservation
Though the western mastiff bat is listed under the Least Concern Category by the
IUCN Red List of Threatened Species,
Bat Conservation International
Bat Conservation International (BCI) is an international nongovernmental organization working to conserve bats and their habitats through conservation, education, and research efforts.
BCI was founded in 1982 by bat biologist Merlin Tuttle, w ...
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.
The loss of cliff sites due to urban development has also contributed to the species' endangered status, as it has become difficult to find suitable roost sites.
References
External links
{{Taxonbar, from=Q301308
Eumops
Bats of North America
Bats of Central America
Bats of South America
Bats of Brazil
Bats of Mexico
Bats of the United States
Mammals of Argentina
Mammals of Bolivia
Mammals of Colombia
Mammals of Ecuador
Mammals of Paraguay
Mammals of Peru
Bat, Western
Bat, Western
Mammals described in 1821