Pinto Bat

Perception Channels: tactile ; chemical

Very little is known about the distribution of the population of this bat. The lack of natural history data places it in class 2, requiring more information. Because the Spotted Bat seems to forage in various habitats, conservation of diurnal roosts, rocky cliffs that have snug cracks for roosting, seem to be the best way to protect this species. However large open foraging sights, where their echolocation is most effective, are important to the conservation of this species, as well as the availability of large moths as prey.

Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Euderma maculatum mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

unknown

Unknown, but as a specialist on moths they might be important in controlling specific moth populations

Like most Microchiroptera, the Spotted bat is an echolocator, but uses very low frequencies to locate prey (9-12kHz). These frequencies limit the Spotted bat to catching large flying insects, apparently specializing on large moths that cannot detect echolocation calls of such low frequencies. Insects seem to be caught in the air at a rate of about one every 45 seconds, and most recorded foraging behavior occurred from 11 pm to 3 am.

(Wai-ping and Fenton 1989; Watkins 1977).

The Spotted bat has a patchy distribution, occurring from northern Mexico to British Columbia. They are seldom abundant. Recorded observations extend from the Pacific coast to the Rocky Mountains inland.

Biogeographic Regions: nearctic (Native )

Spotted bats have been found foraging in many different habitats, especially in arid or Ponderosa Pine forests, and marshlands. Because of the low frequency of their echolocation calls large open habitat is predicted to be preferred. However, it is believed that the distribution of suitable diurnal roosting sites is cause for the patchy distribution of this species. Spotted Bats roost in the small cracks found in cliffs and stony outcrops. They have been found as high as 3000m above sea level, and even below sea level in the deserts of California.

(Pierson and Rainey 1998; Poche 1981; Watkins 1977)

Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; forest ; mountains

Total length, 126 mm; tail, 51 mm; hind foot, 12 mm; ear, 47 mm; forearm 48.51 mm. The Spotted bat is so named for its three white spots located over each shoulder and on the rump. The surrounding dorsal fur is black while the ventral fur is light with dark underfur. The face is black and the ears and wings are pale.

Range mass: 16 to 20 g.

Other Physical Features: endothermic ; bilateral symmetry

The female gives birth to one young weighing 20% of her body weight usually around June. Young do not have the spots of the adults, nor fully developed ears at birth. Juveniles have been caught in mist nets in July. Lactating females have been caught as late as August.

(Watkins 1977)

Range number of offspring: 1 to 1.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous

The spotted bat is a species of vesper bat (Family Vespertilonidae). Joel Asaph Allen described the bat in 1891. The bat is 10-12 cm long with a 35-3 cm wingspan, 4 cm long ears and weighs 15-20 g. It has mainly jet black fur with two large white spots on its shoulders and one white spot on its rump. The fur on its underbelly is snow white. The wings are pink in color and the ears have a pinkish tone. Total length, 126 mm; tail, 51 mm; hind foot, 12 mm; ear, 47 mm; fore­arm 48.51 mm. The Spot­ted bat is so named for its three white spots lo­cated over each shoul­der and on the rump. The sur­round­ing dor­sal fur is black while the ven­tral fur is light with dark un­der­fur. The face is black and the ears and wings are pale. It lives in undisturbed roosts on cliffs in arid regions along the Grand Canyon in Arizona, as well as open and dense deciduous and coniferous forests (especially Pon­derosa Pine forests) , hay fields, deserts, marshes, riparian areas and dry shrub-steppe grasslands in rugged landscapes in Nevada, Montana, Nevada, Wyoming, Arizona, California, Colorado, Utah, and British Columbia, Canada and into central Mexico from the Pa­cific coast to the Rocky Moun­tains in­land. It may occur at 3000m above sea level or below sea level in the deserts of Cal­i­for­nia (Pier­son and Rainey 1998; Poche 1981; Watkins 1977). Their habitat is associated with a water source such as a spring, creek, river or lake. This species seems to be roost faith­ful; they re­turn to the same di­ur­nal roost every night in the sum­mer. In the Au­tumn their be­hav­iour be­comes less pre­dictable. Typ­i­cally at a site usu­ally only one is caught per night; in­di­vid­u­als are well dis­persed, sep­a­rated by dis­tances of 750-1000m of each other. Some bats migrate from colder to warmer regions in winter, such as Pon­derosa pine high el­e­va­tion habi­tats in June and July to lower el­e­va­tions in Au­gust. Bats enter torpor in cold weather; the body temperature falls to that of their surroundings and the heart rate slows. They roost in the small cracks found in vertical cliffs and stony out­crops and in open canyons. The bat rolls of its ears around its head when it rests. When it becomes active, the ears inflate with blood and unroll. The bat is solitary and territorial. Its echolocation sound (9-12kHz) is low enough to be heard by humans. It uses vo­cal­iza­tions to com­mu­ni­cate with neigh­bours. An ap­par­ent ter­ri­to­r­ial dis­pute in­volved vo­cal­iza­tion and di­rect con­tact. Only in one study had the bat for­ag­ing in groups. In most stud­ies the bats for­age up to 10 km from their di­ur­nal roost and seem to for­age con­stantly. They fly in el­lip­ti­cal pat­terns from their roost­ing sites. A lac­tat­ing fe­male flew 35.8 km straight from her di­ur­nal roost around 23:00 h to a for­ag­ing site, roosted there for part of the night (01.00-03.30 h) and flew back to the cliff day roost. Other bats at the lo­ca­tion fol­lowed that nightly pat­tern. This be­hav­ior could be a com­pro­mise be­tween suit­able di­ur­nal roost­ing sites and for­ag­ing sites. For­ag­ing be­hav­iour does not seem af­fected by the amount of moon­light at night. The bat feeds mainly on grasshoppers and moths; it tears off a moth's wings and only eats the addomen. The low fre­quen­cy calls limit the bat to catch­ing large fly­ing in­sects, ap­par­ently spe­cial­iz­ing on large moths that can­not de­tect echolo­ca­tion calls of such low fre­quen­cies. In­sects seem to be caught in the air at a rate of about one every 45 sec­onds and most recorded for­ag­ing be­hav­iour oc­curs 11 pm-3 am. Natural predators include owls, raccoons and skunks. The mating season is in autumn and females usually produce one young in June or July. The newborn pup weighs 20% of the adult weight and does not have the distinctive color pattern and fully developed ears of the adults. It may fly by July, but lac­tat­ing fe­males have been caught as late as Au­gust. The bat may live up to 20 years in the wild. The biggest threat to the bat is human-caused changes to the environment. Bats may acccumulate pesticides through their diet. Using DDT and other insecticides in the 1960s led to a severe decline in the spotted bat population, but the bat is more common than formerly believed and is listed 'LeastConcern' by the IUCN Red List. It is thought to be one of the rarest bats in North America and a species of special concern. In the 100 years from the time of its dis­cov­ery to 1990, only 14 in­di­vid­u­als were col­lected in Cal­i­for­nia. Since then the num­ber of lo­ca­tions where spot­ted bats have been found in that state has tripled. While the dis­tri­b­u­tion is very patchy over this range, the species may be lo­cally com­mon. It occupies a very large range, but is sel­dom abun­dant. Con­ser­ving di­ur­nal roosts (rocky cliffs with snug cracks for roost­ing), seems the best way to protect this bat. Large open for­ag­ing sights, where their echolo­ca­tion is most ef­fec­tive, and large moths for prey are im­por­tant con­ser­ving the bat. Compiled using Animal Diversity Web (http://animaldiversity.ummz.umich.edu/accounts/Euderma_maculatum/), Arizona-Sonora Desert Museum (https://www.desertmuseum.org/kids/bats/Spotted%20bat.php) and Wikipedia (en.wikipedia.org/wiki/Spotted_bat) The author for the Animal Diversity Web website was Sofia Hus­sain and the editor was James Pat­ton, both from the Uni­ver­sity of Cal­i­for­nia, Berke­ley.

The spotted bat (Euderma maculatum) is a species of vesper bat and the only species of the genus Euderma.