Long-Eared Myotis
The long-eared myotis has the longest ears of any myotis found in Colorado.
About This Species
The long-eared myotis is not uncommon in parts of Colorado, but little is known of its biology here or elsewhere over its range. Black membranes contrast with the medium yellowish-brown fur. The belly is paler than the back. Hairs are lead-gray at their bases. The only species with which the long-eared myotis might be confused is the fringed myotis, which has shorter, narrower ears and a conspicuous fringe of stiff hairs on the trailing edge of the uropatagium.
Living with Bats
There are 18 species of bat that call Colorado home. These amazing mammals are not only fantastic insect control, but are also valuable pollinators. Learn more about how humans and bats can live in harmony in our guide.
Bat Conservation
Bats remain one of the most mysterious land mammals, especially in Colorado, where 18 species spend at least part of the year. For example, the little brown bats in our state seem to hibernate differently than those on the east coast, and we are constantly learning about their whereabouts, habitats and behaviors. Our current research suggests that bat populations in Colorado are doing quite well.
One little brown bat can eat up to 18,000 small insects (like mosquitoes) each night. Their economic impact is estimated to be billions of dollars, and much of the agricultural industry relies on their insect control.
Beyond their economic impact, bats flaunt some impressive adaptations. They are the only mammal that truly flies, which requires a very unique anatomy. Their upside-down lifestyle requires adaptations in their “feet” to consistently grip. If people hanged upside down for even an hour, we’d lose consciousness; bats have developed amazing blood pressure accommodations to fit the lifestyle.
We are currently involved in a monitoring partnership called the North American Bat Monitoring Program (NA Bat). The program utilizes acoustic surveys to collect information on bat populations without interfering with their behaviors. We also are using PIT tags, like the chips put in household pets, to monitor a number of maternity sites. While data collection will take years, we’ve already learned new information about Colorado’s bat population, the most heartening of which is that the population appears larger and more widespread than we’d thought. This is an excellent start to learning more about the species, but we’ve got lots of problem-solving and technological innovation left to do.
Our priorities also include learning more about bats so that we are prepared for the potential spread of White-nose Syndrome. Finding and monitoring bats is crucial to this effort, but also comes with its own challenges. Because bats are small, flying mammals, much of the equipment used to track other species is too heavy for them. And during the winter, Colorado bats are very elusive, choosing to hibernate in small groups often in locations that are inaccessible to people.
More Information:
Physical Characteristics
Measurements average: total length, 86.4 mm; length of forearm 37.6 mm; wingspan, 275 mm; weight 6.1 g.
Range
Like the Yuma myotis, this species ranges from central Mexico north to British Columbia, but it ranges farther east to the western edge of the Great Plains, including the western Dakotas and Nebraska. Thus, this species occurs at moderate elevations throughout the western three-fifths of Colorado, at elevations from 5,000 to 9,800 feet.
Habitat
The long-eared myotis is a species of coniferous forest, on both sides of the Continental Divide. Ponderosa pine woodland is the most common habitat type, although the animals also range down into pinyon-juniper woodland, where they may be abundant. Roosts are in rock crevices, trees (often behind loose bark), sheds, cabins, caves, abandoned mines and other such sheltered areas. The long-eared myotis are thought to hibernate in Colorado, as late fall activity has been documented in mines and caves, but individuals have rarely been found in winter. Hibernation sites include mines, caves, and probably rock crevices.
Diet
The long-eared myotis emerges after dark to forage near trees or over water. The animals are gleaners, hovering to take prey from leaves in forest gaps and edges. Principal food items are moths, flies, spiders and beetles.
Reproduction
Reproduction has not been studied in detail, and dates of breeding are unknown. Males with scrotal testes have been captured in July, August and September. Females may form small nursery colonies of one to three dozen individuals or roost alone. In Colorado, pregnant females are most common in June and July. Lactating females have been captured in June, July and August. A single young is born. Probably, the gestation period is 50 to 60 days, as in other species of myotis of similar size.