The Hawaiian Hoary Bat: Five Amazing Facts

Hawaiian Hoary Bat

As we near end of October and leading up to the spookiest time of the year, join us in celebrating National Bat Week, October 24-31. Bats are enigmatic, cryptic and contribute in fascinating ways to the overall health of an ecosystem.

While not the easiest to see, you can find bats in nearly every environment in the United States. Bats are an evolutionary wonder as this land mammal takes flight and leaves its land bound mammal cousins on the ground. With over 1,300 species, bats come in a variety of shapes and sizes. However, Hawaii has the distinction of being home to one of only three subspecies of bats.

The endangered Ope‘ape‘a, Hawaiian hoary bat, is a Hawaiian treasure. As life on the Hawaiian Islands has evolved in geographical isolation, so did the Ope‘ape‘a.

Here are amazing five facts about Ope‘ape‘a that are truly intriguing!

1. How far is far. The Hawaiian archipelago contains some of the most captivating scenic wonders on the planet. These lush landscapes are home to thousands of species of insects, plants and wildlife. However, in an island of plenty, only two mammals are endemic to Hawaii. The Ope‘ape‘a is one of only two Hawaiian evolutionary endemic mammal inhabitants – the ‘Ilio holo I ka uaua, Hawaiian monk seal, is the second. Which makes sense if your home is 3,600 kilometers away from the nearest continent. The Hawaiian island chain is one of the most remote islands in the world.

Photo courtesy of Brett Amy Thelen/Aschuelot Valley Environment/CC BY-NC-ND 2.0

2. Good things come in pairs. Every summer sees the possibility of Ope‘ape‘a pups making their first appearance into the world. Ope‘ape‘a breed during the summer months and when they give birth, they do so in pairs. Female Ope‘ape‘a, like their North American mainland cousins, give birth to twin pups. Just because being a mother twins isn’t enough they also do so upside down.

Photo: The hoary in Hoary Bat refers to the frost of white hair that highlights its body. Photo courtesy of Nessie Grace/CC BY-NC-ND 2.0

3. Best bug zapper out there. Bats are incredible acrobatic insect eating machines. The Ope‘ape‘a can eat as much as 40% of it body weight in bugs. They dart through the air – dining and dashing – eating moths, beetles, crickets, mosquitoes, and termites.

Photo: The average wingspan of the Ope‘ape‘a is approximately one foot in length. Photo courtesy of Michael Pennay/CC BY-NC-ND 2.0

4. Here before humans. As more research into the origins of the Ope‘ape‘a continues, scientists have determined two possible periods of bat migration to the Hawaiian archipelago. The more ancient migration may have occurred approximately 10,000 years ago and the second migration being more recent, 800 years ago.

Photo: The Ope‘ape‘a is smaller, approximately 30% to 45%,  than hoary bats in Northern and South America. Photo credit: USFWS

5. A symbol of Hawaii. Since the migration of the Ope‘ape‘a to Hawaii, they have been making the Hawaiian Islands a better place. Just as with their avian neighbors, bats help pollinate the forest. They keep the island insect populations in check. Bats like the Ope‘ape‘a help maintain their habitats and in turn those habitats serve so many other species of wildlife. In 2015, to celebrate and honor the Ope‘ape‘a, state lawmakers designated the Ope‘ape‘a as the official state land mammal of Hawaii.

Learn more about the bats of the Pacific Islands:

Ope‘ape‘a - Hawaiian hoary bat

Fanihi - Mariana fruit bat

Pe'a and pe'a vao - Samoan flying fruit bat