Have You Spotted This Bat?
Flying superhero eats its weight in bugs
High above the canyons of Colorado National Monument flies one of the state’s most elusive creatures.
A winged crusader in bold costume, he patrols the Grand Valley, pursuing the insect hordes that threaten to overrun us.
Concealing himself on high cliffs during the day and emerging only in darkness, little is known about this large-eared hunter and scientists are eager to learn more.
They want to know — Have you spotted this bat?
The Spotted bat (Euderma maculatum) is one of Colorado’s larger bats and may be this state’s most unusual-looking mammal.
A mature bat is about four and a half inches from nose to tail with a wingspan of about 14 inches, but what’s distinguishes this flying mammal is its outrageously long ears and bold coloration.
The fur on the bat’s body is black with three large white spots that suggest two eyes and a mouth.
Biologists speculate that these markings may function to scare off predators, similar to the way the eyespots on butterfly wings protect those delicate fliers.
Unfortunately, very little is known about the Spotted bat because it is difficult to catch.
It roosts in crevices on high cliff faces and it tends to fly above the reach of bat biologist’s nets when hunting for insects.
It was not observed in Colorado until 1982 and until recently had only been seen at Dinosaur National Monument and Mesa Verde National Park.
Biologists at Colorado Parks and Wildlife suspected that the Spotted bat also occur in our area because the cliffs in Colorado National Monument are similar to the habitats where it was found in Mesa Verde but they had no proof.
Then, in 2011, a resident in Mack brought in to the Grand Junction CPW office a dead bat, likely killed by a housecat, that he had found on his property.
Parks and Wildlife biologist Dan Neubaum was very excited.
Not only was it a Spotted bat — it was a lactating female, which meant that the bats were breeding in the area.
Oddly enough, you are more likely to hear Spotted bats than see them.
Many bats emit high-pitched sounds that bounce off objects in their environment and return to the bats ears as echoes.
Bats use these echoes to “see” in the dark and locate objects, such as insects. This is called echolocation.
Although most echolocation calls are so high-pitched that human ears cannot hear them, two bat species in our area have calls that are low enough in pitch that they are audible to humans, at least those of us with good hearing.
If you are down by the Colorado River at nightfall and you think you are hearing bats, do not be alarmed.
You aren’t turning into batman or a vampire — you are hearing either a Spotted bat or a Big Free-tailed bat.
Their similar-sounding calls are difficult to tell apart unless you have a highly trained ear, but will sound like two small metal balls being repeatedly struck together.
The sound will be moving as the bat flies around rather than stationary like most insect sounds.
CPW biologists are hoping to do a survey of Colorado National Monument soon to get a better picture of the bat species that are present there.
In the meantime, Neubaum says they’d love to hear from the public if they have seen a Spotted bat or have any information about bat roosting sites in the area.
If you find a bat on the ground, please do not handle it — bats can carry diseases such as rabies.
Transmission of rabies from bats to humans is very rare, but may occur when a bat is improperly handled.
In spite of their mixed reputation, bats overall do us much more good than harm — bats consume not only mosquitos, but are also one of the most important predators of insect pests that attack crops.
We are lucky to have bats and we are especially lucky to have the Spotted bat. Try and spot one!
(Meredith Swett Walker is a trained biologist and nature writer living and working in Grand Junction. She also can be followed on her blog http://picahudsonia.com/).