The Hawaiian bat has a lonely life. Most native animals in Hawaii are resting, the day's activity behind them, when the Hawaiian hoary bat or opeapea stretches its wing at sunset, dominating the Hawaiian night sky.

No other animal in Hawaii has a lifestyle like the Hawaiian bat (Lasiurus cinereus semotus). This furry flier is the only native mammal of Hawaii that lives entirely on land. The only other native mammals of Hawaii are those marine mammals. "Native" describes any creature that arrived in Hawaii without the aid of humans. So it is reasonable that the only native of Hawaii are those that can fly or swim. The journey to reach Hawaii is so long and difficult that only one species of bat (from North America) ever arrived making the Hawaiian bat the only bat around, and nearly the only native mammal.

During the day, while the world is noisy, Hawaiian bats rest alone in trees, hanging upside down like most other bats. Often they have a favorite tree, even a favorite branch to spend the daylight hours. When the sky is changing as evening approaches, the Hawaiian hoary bat begins its solitary nocturnal hunt for food. These bats are world class acrobats performing dizzying loops and turns as they swoop after nocturnal insects using echolocation (similar to sonar). There is no other animal in Hawaii that can compete with the Hawaiian hoary bat as an aerial nocturnal predator; there is nothing quite like it!

Being lone and exclusive has benefits. Because there is so little competition for the Hawaiian bat in the evening sky, this animal was able to spread unrestricted to many types of environments in Hawaii. The Hawaiian bat began to expand its diet, eating more types of flying insects than its north American ancestor. In addition, the Hawaiian bat began foraging in wooded areas as well as the open lands that its ancestors traditionally used. In time, the bodies of the Hawaiian bats changed to permit slower, more maneuverable flight near vegetation.

Wooded areas, pastures, and the alpine shrubland of Haleakala National Park are areas where this little brown bat can be observed flying or hunting. From December to March, the Hawaiian bat move up into the mountains and go into "torpor" - a deep resting period of inactivity, much like hibernation. The spring brings about a flurry of activity as bats "wake up" and move back down to lower elevations. Although the Hawaiian bats mate in the fall, the female stores the male's sperm until spring. Gestation is about 80 days before the single pup (baby bat) is born around June.

Due primarily to habitat loss, the Hawaiian hoary bat was federally listed as endangered in 1970. There are less than 2,500 individuals in all the Hawaiian Islands. Despite this low population the prognosis for recovery is high because of the bat's ability to use many different types of habitats and because there are populations on each of the main islands. In certain areas on Maui, including the alpine shrubland of Haleakala National Park, they are frequently seen. Hawaiian hoary bats have an uncommon combination of rarity and conspicuousness which make them special and entertaining sight swooping in solitude over the Hawaiian sunset.

To check out other endangered species living in National Parks, check out the NPS Threatened and Endangered Species website.