Lasiurus seminolusseminole bat

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Geographic Range

Seminole bats are distributed widely across the Gulf Coast States ranging from East Texas to the Southern Atlantic coast and to the northern parts of Arkansas and North Carolina. Their northern range is limited to a maximum latitude of 42° 27'. There have been some questionable reports of seminole bats in the southern portions of Wisconsin and New York, but these could have simply wandered out of their summer range. During winter, abundance of seminole bats increases in the southern portion of their range and decreases in the northern portion. (Kunz and Racey 1998, Wilhide et al. 1998)

Habitat

Generally, seminole bats are found in lowland forest stands of mixed deciduous and pine trees. Although several bats may be found hanging together, roosting alone is more common. They hang 1.5 to 6.1 m above the ground on the southwest side of trees, clinging to the inside of clumps of Spanish moss (Tillandsia usneoides), leaves, or loose bark. The area directly below the moss where they hang is clear of other branches. This allows these bats to drop down to begin their flight. The ground beneath them is covered with leaf litter and other organic debris. This reduces the amount of sunlight that is reflected on them when hanging.

Roosting is more common in pine trees, especially during parturition and lactation. The trees that are selected for roosting are taller and larger in diameter than other trees near the roost area. Selected trees are also tend to be near forest edges that permit easy flight paths. (Constantine 1958 and 1966, Barbour and Davis 1969, Menzel et al. 1998)

Physical Description

Seminole bats range in length from 108 to 114 mm. They weigh approximately 7 to 14 g. Females are slightly larger than males. Body length ranges from 44 to 52 mm with a hindfoot length of 8 to 9 mm and a forearm length of 35 to 45 mm. The short, rounded ear averages 11 mm in height with a very short, rounded tragus.

Seminole bats were long considered to be a subspecies of red bats (Lasiurus borealis). Since they are of similar size and appearance, they are easily confused with each other. The lacrimal shelf, which is not well developed in seminole bats compared to red bats, and color of the fur are the features used to distinguish these species. Seminole bats have rich, mahogany brown pelage with whitish tips. The underside is paler than the back. The throat and chest are whitish. The area under the arms to the wrist and the uropatagium are entirely furred. (Barbour and Davis, 1969; Hall and Kelson, 1959; Laerm, et al., 1999; Wilson and Ruff, 1999)

Their basal metabolic rate (BMR) in relation to body weight is lower than in most other mammals. When foraging is limited during the fall and winter seasons, a lower BMR is exhibited resembling a hibernating rather than a non-hibernating mammal. (Genoud, 1990)

  • Sexual Dimorphism
  • female larger
  • Range mass
    7 to 14 g
    0.25 to 0.49 oz
  • Range length
    44 to 52 mm
    1.73 to 2.05 in
  • Range wingspan
    108 to 114 mm
    4.25 to 4.49 in

Reproduction

Mating behaviors are not known in seminole bats.

Mating occurs in flight during the fall. It is thought that the sperm is stored during the winter, and then 1 to 4 young are born in late May to early June. Gestation period is from 80 to 90 days. An average of 3.3 young are born per breeding season, which is unusual as most bats have only one young per litter. These young can fly as soon as 3 to 4 weeks after birth and young probably reach sexual maturity in the year following their birth. (Barbour and Davis 1969, Wilson and Ruff 1999)

  • Breeding season
    Births occur from late May to early June.
  • Range number of offspring
    1 to 4
  • Average number of offspring
    3.3
  • Range gestation period
    80 to 90 days
  • Range weaning age
    21 to 28 days
  • Average age at sexual or reproductive maturity (female)
    1 years
  • Average age at sexual or reproductive maturity (male)
    1 years

Young are cared for by their mother until they are weaned and can fly, at which point they become independent, although there may be some association of mother and offspring for a short period after the young begin to fly.

Lifespan/Longevity

There have been no longevity studies on seminole bats. It has been noted that more females than males have been recorded in the older age class, which indicates a higher male mortality rate. If seminole bats survive the perils of youth, it is likely that they will live for many years. (Kunz and Racey 1998)

Behavior

Lasiurus seminolus is a solitary bat species. Individuals usually roost alone and remain in the roost whenever the temperature is below 21°C. If the relative humidity increases, they are able to fly at lower temperatures. A sighting was reported at 20°C when the relative humidity was 38%. They do not hibernate, but do go into torpor. These bats fly throughout the year and have been spotted on warm days in the middle of winter. Seasonal migration does occur within their range in the southeastern United States. There are fewer seminole bats in the northern portions of their range during the winter, but in the south they are one of the most abundant bats active at that time of year. They have been known to join groups of migrating birds on southward migrations. No studies have yet been done to determine how they navigate their migration route. The possibilities include visual landmarks, smells, or winds. (Constantine 1958, Neuweiler 2000)

Communication and Perception

Food Habits

Seminole bats are insectivorous. They feed at dusk, while in flight, on flies, beetles, dragonflies, bees, wasps, and crickets. They are quick and direct when flying, feeding mostly near the tops of trees at about 6 to 15 m. However, it is not uncommon to see them over open ponds, along forest edges, or near lights, presumably where insects accumulate. Like most microchiropterans, seminole bats find their insect prey through echolocation. (Genoud, 1990)

  • Animal Foods
  • insects

Predation

Predators of seminole bats include blue jays, snakes, and raptors. A study of the stomach contents of an opossum (Didelphis virginiana) and a striped skunk (Mephitis mephitis) revealed the remains of seminole bats. (Constantine, 1958; Wilson and Ruff, 1999)

Ecosystem Roles

Seminole bats play an important role in their ecosystems by consuming large quantities of flying insects.

Economic Importance for Humans: Positive

Insect control within the ecosystem is an important role of seminole bats. Bats can positively impact agriculture to a tremendous extent through their predation on common insect pests.

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

Bats can become infected with rabies. The incidence of rabies in seminole bats is low, however, with a reported infection in Florida of 0.6%. During times of torpor, seminole bats are prone to predation from their roosts which are open to the ground. If an infected seminole bat defends itself from a predator, it may pass on rabies. Although no reports confirm this, an increase in rabies does coincide with cooler temperatures when bats are torpid. (Constantine 1958, Wilson and Ruff 1999)

Conservation Status

Although they are common in some parts of their range, seminole bats are listed as a species of special concern in Oklahoma.

Since these bats roost primarily in Spanish moss, the gathering of this moss could affect roosting behavior. No studies have been done to determine whether there has been an impact, but educating moss collectors about these roosting requirements could help seminole bats.

This species is rated "Lower Risk, of least concern" by the International Union for the Conservation of Nature. (Texas Parks & Wildlife, 2000; Wilson and Ruff, 1999)

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 Lasiurus seminolus mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America. (Cryan, 2010; National Park Service, Wildlife Health Center, 2010)

Other Comments

Another common name for this species is mahogany bat. Lasiurus seminolus had previously been named Atalapha borealis seminola and Nycteris seminola. The species name comes from the Seminole Indian tribe, who resided in the area where these bats were first discovered.

A seminole bat in captivity ate boiled eggs, cooked liver, and crickets. When flying around an enclosed room, the bat dragged its chin on the shiny linoleum floor apparently mistaking the shining surface for water. (Constantine 1958)

Contributors

Terri Walker (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

insectivore

An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

sperm-storing

mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Barbour, R., W. Davis. 1969. Bats of America. Lexington, KY. U.S.A.: The University Press of Kentucky.

Constantine, D. 1958. Ecological observation of lasiurine bats in Georgia. Journal of Mammalogy, 39: 64-70.

Constantine, D. 1965. Ecological observation of lasiurine bats in Iowa. Journal of Mammalogy, 47: 34-41.

Cryan, P. 2010. "White-nose syndrome threatens the survival of hibernating bats in North America" (On-line). U.S. Geological Survey, Fort Collins Science Center. Accessed September 16, 2010 at http://www.fort.usgs.gov/WNS/.

Genoud, M. 1990. Seasonal variations in the basal rate of metabolism of subtropical insectivorous bats: a comparison with other mammals. Revue Suisse de Zoologie, 97(1): 77-90.

Hall, R., K. Kelson. 1959. The Mammals of North America. Washington D.C. U.S.A.: The Ronald Press Company.

Kunz, T., P. Racey. 1998. Bat Biology and Conservation. Washington D.C. U.S.A.: Smithsonian Institution Press.

Laerm, J., M. Menzel, D. Krishon, J. Boone. 1999. Morphological discrimination between the eastern red bat and seminole bat in the southeastern United States. Journal of the Elisha Mitchell Scientific Society, 115(3): 131-139.

Menzel, M., T. Carter, B. Chapman, J. Laerm. 1998. Quantitative comparison of tree roosts used by red bats and seminole bats. Canadian Journal of Zoology, 76(4): 630-634.

Menzel, M., D. Krishon, T. Carter, J. Laerm. 1999. Notes on tree roost characteristics of the northern yellow bat, the seminole bat, the evening bat, and the eastern pipistrelle. Florida Scientist, 62(3-4): 185-193.

National Park Service, Wildlife Health Center, 2010. "White-nose syndrome" (On-line). National Park Service, Wildlife Health. Accessed September 16, 2010 at http://www.nature.nps.gov/biology/wildlifehealth/White_Nose_Syndrome.cfm.

Neuweiler, G. 2000. The Biology of Bats. New York, NY. U.S.A.: Oxford University Press.

Texas Parks & Wildlife, 2000. "Nature: Seminole Bat" (On-line). Accessed October 28, 2001 at http://www.tpwd.state.tx.us/.

Wilhide, J., B. Baker, D. Saugey. 1998. Arkansas range extension of the seminole bat. Journal of Arkansas Academy of Science, 52: 140-141.

Wilson, D., S. Ruff. 1999. North American Mammals. Washington D.C. U.S.A.: The Smithsonian Institution.