Two subspecies exist: M. e. evotis of the mountains and high plains of the western U.S. and soutwestern Canada, and M. e. pacificus of coastal regions of the Pacific Northwest. (Manning and Jones, 1989; Manning, 1993)
- Range elevation
- 0 to 2,830 m
- 0.00 to ft
Myotis. The tragus is long and slender. The calcar has little to no keel. The auditory bullae are relatively large compared to other Myotis bats. The dentition is 2/3, 1/1, 3/3, 3/3. Total length, observed in a population of South Dakota bats, ranges from 87 to 100 mm.is dull to pale brown or straw colored with black ears and membranes. The ears, ranging between 19 and 22 mm in length, are the longest of any North American
exhibits very little sexual dimorphism, with females being a bit larger than males, though only showing slight differences of length in ear and fifth metatarsal.
There is evidence of geographic variation in size. Specimens offrom British Columbia have larger skulls than those from Washington; Washington bats are more similar to those found further inland.
Myotis keenii. The two are sympatric in coastal areas of British Columbia and Washington. The geographic variation of has made it difficult to distinguish between the two, and in some collections, identification errors have been made. No external features have been identified that clearly seperate the two species. The skull of contains a longer tooth row than that of M. keenii. The distance from the last upper pre-molar to the last upper molar is greater than 4.2 mm. Another Myotis species that is difficult to distiguish is Myotis septentrionalis, commonly known as northern long-eared myotis. Longer tooth row and longer ears help distinguish . (Manning and Jones, 1989; Nagorsen and Brigham, 1993; Van Zyll De Jong and Nagorsen, 1994)morphologically overlaps with
- Sexual Dimorphism
- sexes alike
- female larger
- Range mass
- 5 to 8 g
- 0.18 to 0.28 oz
- Range length
- 87 to 100 mm
- 3.43 to 3.94 in
- Average wingspan
- 250 mm
- 9.84 in
Mating systems for Myotis species can be inferred, actual data for do not exist.are relatively unkown. Although some similarities to other
Most species of the genus for which there are data appear to be polygynandrous. Myotis myotis mating involves the females from different colonies traveling several miles to male roost sites. Little is observed in male behavior in attracting females. Reproduction in Myotis lucifugus involves copulation and insemination prior to hibernation. The sperm are then stored in the uterus until spring. (Vaughn, et al., 2000; Zahn and Dippel, 1997)
- Mating System
- polygynandrous (promiscuous)
Records ofreproduction are very incomplete. Most data are either based upon anecdotal accounts or museum specimens. The young are born in late spring/early summer. Lactating females have been collected in July and August. reproduces once per year, and females may form maternity colonies of 5 to 30 individuals in the summer (colonies may contain a few males), or they can remain solitary.
The young are born naked with sharp milk teeth. Size of the neonates ranges around 7 to 8 cm, with a weight of around 1 to 1.5 grams. (Manning and Jones, 1989; Manning, 1993; Nagorsen and Brigham, 1993)
A study of reproducing females in Alberta produced some interesting data on roost differences between pregnant and lactating females. Pregnant females roost in horizontal rock crevices, which are closer to the surface, warm rapidly, and have a higher mean daytime temperature. Pregnant females can maintain a higher body temperature at a lower cost to them by roosting in a warmer place. The horizontal surface rock crevices cool very quickly, however the bats spend these cool hours foraging. When they return to the cold roost, they drop into torpor until passively warmed by the ambient temperature, thus saving more energy for use towards fetal development.
Females who had given birth to young used deeper vertical rock crevices, which maintain a higher overall temperature. Juveniles that are left in the roost while the mother forages can not effectively maintain their high body temperatures. Vertical rock crevices fluctuate less in temperature, keeping the juveniles warmer and more stable. (Chruszcz and Barclay, 2002)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- breeds once per year.
- Breeding season
- Mating occurs in autumn or early winter.
- Range number of offspring
- 1 to 1
- Average number of offspring
- Range gestation period
- 40 to 60 days
- Parental Investment
- no parental involvement
The lifespan of these animals has been reported as a maximum of 22 years in the wild. It is unlikely that most individuals live that long.
- Range lifespan
- 22 (high) years
- Range lifespan
- Average lifespan
- 2.2 years
- Max Planck Institute for Demographic Research
- Average lifespan
is either solitary or roosts in colonies of up to 30 individuals. Both sexes use a variety of roost sites. In the Pacific Northwest, the variety of female roost sites exceeds that of any other bats in that area. In forest populations, these bats usually roost in large snags in canopy gaps, or else in stumps in clear-cut areas. They will roost in stumps instead of competing with other species for the relatively small remaining number of large conifer snags. Snags in canopy gaps and stumps receive more sunlight, thus maintaining a higher ambient temperature. are hypothesized to lower their thermoregulatory costs by using the sun to passively warm their bodies after a state of torpor. The re-warming is the most energy-demanding phase of torpor for bats.
Solitary behavior leads to added hardship due to the inability to take advantage of heat accumulation in roosting groups, or maternity colonies. Torpor results in slowed embryonic development, prolonged gestation, and reduced milk production in reproducing females. This delayed parturition or weaning of young is quite detrimental to a temperate zone bat, because the feeding season is already truncated. Unique feeding behaviors have ameliorated these problems for (Chruszcz and Barclay, 2002). However, at the edge of their range these bats exist on a very tight energy budget.
The size ofhome ranges has not been reported.
Communication and Perception
Echolocation is essential to (Faure and Barclay, 1992), as it is through this means that these bats are able to capture their prey. Echolocation can be used in different ways when capturing prey. Changing calls or ceasing calls are both options for capturing prey in different situations. Although echolocation is the main means of capturing prey when “hawking” insects from the air, will cease calling and use prey-generated sounds to guide the attack. This ability has many ramifications in feeding behavior, habitat range, and prey selection for . Tympanate moths are a primary food source, and these foraging tactics make all the more effective at capturing prey in the air or off a surface.
Other forms of communication or uses for echolocation for Myotis lucifugus was observed to use echolocation in identifying roosts, mating sites, hibernation sites and feeding areas. Other bats have been found to react aggressively to echolocation calls of conspecifics thus maintaining spacing between individuals. Echolocation can also facilitate mother-young recognition. (Vaughn, et al., 2000)are not completely known. Other echolocating bats have been found to actually use echolocation as a means of communication with each other.
Although reports in the literature are absent, we may infer that mothers and their young use some tactile communication. It is also likely that this type of communication occurs between mates. Chemical communication has not been reported for these animals.
is insectivorous. These bats emerge to feed approximately one hour after dark. They prey mainly on moths, but their diet also includes beetles, flies, and spiders. They can take prey from the air (hawk) as well as from surfaces (glean). The ability to incorporate both methods of foraging requires a pattern of flight that is slow and methodical, and which requires more energy compared to the flight patterns of faster-flying bats. Because the methodical flight requires more energy, these bats are forced to forage for prolonged periods. The dual method of foraging also allows for foraging and reproducing in less hospitable climates, due to the access to more than one source of prey. Females can breed in high cool climates, where there is decreased availability of flying insects. can forage for longer periods because it does not rely on a precise heightened insect activity period. Aerially foraging bats focus on peak times of insect abundance, dusk and dawn. can forage throughout the night, and not rely on peak foraging windows.
Although once considered an active prey specialist, M.evotis is actually a passive prey specialist. The selectivity for moths in the diet of this species is due to a biased sensory system that has especially acute ability to perceive prey-generated sounds. The short duration, broad-band, frequency modulated echolocation calls used by are certainly useful for the gleaning of prey off surfaces; however, evidence indicates that they can glean insects from surfaces without use of echolocation. has extremely sensitive low frequency hearing and can use prey-generated sounds to detect prey without the use of echolocation. This was revealed by an experiment with a hidden moth where echolocation could not confirm the location of prey, yet the bat was still accurate in attacking. The advantages of gleaners using a variety of sensory cues are many. Because tympanate moths have evolved a sensitivity to and avoidance of echolocation calls, , which can locate these moths without use of echolocation calls, are more likely to take such moths than are less adept species of bats. (Faure and Barclay, 1992; Faure and Barclay, 1994; Faure, et al., 1990)
- Animal Foods
- terrestrial non-insect arthropods
In populations of Eutamias amoenus) and bears (Ursus americanus), in addition to other common small mammal predators. To avoid these predators, switches roosts frequently. Switching roosts limits the amount of scent that can build up from constant use. In tree bark roosts, the bats often were found face-up at the bottom of the cavity and were well camouflaged. (Vonhof and Barclay, 1996)living in a Pacific Northwest forest of clear-cut stumps, possible predators include chipmunks (
- Anti-predator Adaptations
- Known Predators
- yellow-bellied racers (Coluber mormon)
Economic Importance for Humans: Positive
As an insectivore,has some effect on insect pest control.
- Positive Impacts
- controls pest population
Economic Importance for Humans: Negative
- Negative Impacts
- bites or stings
- causes disease in humans
- carries human disease
is a previous candidate 2 species under the U.S. Endangered Species Act. It has no formal federal status, but is recognized as state sensitive in many areas of the western U.S.
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 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)
Nancy Shefferly (editor), Animal Diversity Web.
Christopher Weber (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.
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.
uses sound to communicate
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.
Referring to an animal that lives in trees; tree-climbing.
- 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.
an animal that mainly eats meat
- causes disease in humans
an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).
uses smells or other chemicals to communicate
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.
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.
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
An animal that eats mainly insects or spiders.
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).
makes seasonal movements between breeding and wintering grounds
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- scrub forest
scrub forests develop in areas that experience dry seasons.
- seasonal breeding
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
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.
uses touch to communicate
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).
Living on the ground.
uses sound above the range of human hearing for either navigation or communication or both
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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Chruszcz, B., M. Barclay. 2003. Prolonged foraging bouts of a solitary gleaning/hawking bat, Myotis evotis . Canadian Journal of Zoology, 81: 823-826.
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Faure, P., R. Barclay. 1994. Substrate-gleaning versus aerial-hawking- Plasitcity in the foraging and echolocation behavior of the long-eared bat, Myotis evotis . Journal of Comparative Physiology, 174/5: 651-660.
Faure, P., R. Barclay. 1992. The sensory basis of prey detection by the long-eared bat, Myotis evotis, and the consequences for prey selection. Animal Behavior, 44/1: 31-39.
Faure, P., J. Fullard, R. Barclay. 1990. The response of tympanate moths to the echolocation calls of a substrate gleaning bat, Myotis evotis . Journal of Comparative Physiology, 166/6: 843-849.
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Vonhof, M., R. Barclay. 1997. Use of tree stumps as roosts by the western long-eared bat. Journal of Wildlife Management, 61/3: 974-684.
Waldien, D., J. Hayes, E. Arnett. 2000. Day-roosts of female long-eared Myotis in Western Oregon. Journal of Wildlife Management, 64/3: 785-796.
Zahn, A., B. Dippel. 1997. Male roosting habits and mating behaviour of Myotis myotis . Journal of Zoology, 243: 659-674.