Milo McIver Park is a bit batty
Many people might associate bats with Halloween, but at Milo McIver State Park they have a history that extends beyond that particular holiday.
The park is home to Townsend's big-eared bats, a species considered sensitive in Oregon and a species of concern at the federal level. During the summer, these bats come to a barn on the property to give birth to their pups. A trail at the park provides information about the species and allows visitors to walk near the barn.
For many years, there were several hundred bats in the state park. That number saw a decline about 12 years ago, but has grown since that time.
Park staff aren't certain of the cause of the decline and rebound, but Ranger Mark Shaw noted that bats are sensitive to humidity and temperature, which could account for the evolving numbers at Milo McIver.
A recent Eagle Scout project will also help the bats who occupy the park.
Riley Herbert, a 13-year-old resident of Southeast Portland who is in the process of earning his Eagle Scout Badge, built 10 bat boxes for the winged creatures. Previously, other Eagle Scouts had built eight bat boxes along the trail in 2002.
Bat boxes are artificial roosts meant to encourage the animals to occupy areas with few roosting sites. At these locations, bats congregate to rest when they are not hunting for food.
Herbert was inspired to pursue the project after camping at Milo McIver with his grandparents this summer.
"While we were camping, they did a bat show and it fascinated me," he said. "I've always liked bats. They've always fascinated me. I like animals that seem weird and odd."
Herbert compared the process of creating the bat boxes to "making an actual house."
"You have to make a plan, get it approved and stay on schedule," he said.
Shaw said the additional bat boxes will be valuable for the creatures.
"We try to give them a variety of options," he said.
The boxes were crafted from cedar wood and painted black, which will create a warm atmosphere for the bats.
Typically, one box can house up to 50 of the animals. The animals also roost in caves, trees or buildings such as the barn at the end of the bat trail at Milo McIver State Park.
The barn, located near the site of the park's original homestead, was likely built in the early 1900s. Over the years, it has been used as a horse concession area and for storage.
Today, the barn is one of the few nursing colonies in the state used by a bat listed as a species of special concern.
"State to state, they're often (listed as) threatened or endangered," Shaw said, noting that hibernating or sleeping bats should not be disturbed. "It makes for a unique feature at the park. It's pretty cool to see those guys."
Mother bats only give birth to one pup each year, and they each have a special call for their child so they can find them in the colony inside the barn. The young bats are nursed until they are able to hunt for moths, beetles and mosquitos on their own. Each night, they consume up to 50 percent of their body weight in insects.
When bats are out feeding, they sometimes use their tail and wings to pull bugs into their mouth, rather than putting it in their mouth directly.
Though many of the bats typically leave the barn in the early fall, those interested can still take a walk through the park and learn about the habitat of the creatures.
The park's bat trail is located next to the equestrian meadow and was described by Shaw as an "easy, family-friendly hike" Adjacent to the equestrian meadow, much of the mile- long trail offers a wooded walk as visitors make their way to the bat barn.
Once visitors reach the barn, there are several informative panels about bats, and a neighboring apple tree is more than 100 years old.
For Herbert, the most interesting thing about bats is their use of echolocation. The process allows them to use sound to find their prey in the dark.
"Even though they might seem weird, they can help with bug problems, and they're a really fascinating species," he said.