Feds Say Hawaiian Hoary Bats Aren’t Endangered Despite Unresolved Questions
Wind farm developers are funding millions of dollars of research that’s helping scientists better understand Hawaii’s imperiled bats.
颁辞谤谤别肠迟颈辞苍:听A previous version of this story incorrectly stated that the Fish and Wildlife Service had announced a proposal to downlist the Hawaiian hoary bat鈥檚 status to threatened, but the agency has so far announced only its intent to propose a status change for the species.
When the furry, rodent-sized Hawaiian hoary bat was declared an endangered species in 1970, little was known about where in the islands it dwelled or what the species required to survive.
The nocturnal night-flyer leaves its roost in the trees only after dark to consume 40% of its body weight in bugs, making its whereabouts difficult to map and its population difficult to count.
But thanks to millions of dollars of recent research funded by the wind farms that threaten the species, scientists now know that the solitary, highly mobile bat roosts, breeds and forages on all of the major Hawaiian islands. It鈥檚 also known to visit Lanai and Kahoolawe.聽A four-year study completed in 2011 suggests that the Big Island population is stable or growing.
Although new research has revealed that the bats are more widely distributed across the island chain than previously believed, it remains a mystery how many of these jeopardized animals exist.
Scientists still don鈥檛 have enough information about the species to estimate its population size.
Despite glaring gaps in scientists’ understanding, Environment Hawaii first reported on Nov. 1 that federal regulators are preparing .
The U.S. Fish and Wildlife Service said the animal, also known as the opeapea, no longer appears to be on the brink of extinction and therefore should be reclassified as a threatened species.
The agency said its decision to develop a proposal to downlist the species is based on a five-year status review published in March that suggests the species is .
The bats would still be protected under the Endangered Species Act as a threatened species. But some conservation groups have expressed concern about reducing the bat’s protective status when scientists still have so much to learn.
鈥淭he real question is will they be protected to the level that they need in order to survive and recover as a threatened species?鈥 said Maxx Phillips, Hawaii Director for the Center for Biological Diversity. 鈥淎nd I just don’t agree. I believe that the best available science shows that these species need the highest level of protection.鈥
Designated the state鈥檚 official land mammal 鈥 and the only land mammal native to Hawaii 鈥 as Environment Hawaii first noted, the Hawaiian hoary bat is under attack from timber harvesting that threatens the homes of adult bats and their dependent pups and coqui frogs that compete with the bats for food.
Wind farms operating at night, when the animal is most active, can lead to collisions that kill an average of 15 bats per year on Oahu, about 11 on Maui and three on the Big Island, according to the five-year status update.
There are eight wind farms operating across the state and one is under construction.
The Center for Biological Diversity said it supports the development of wind energy projects, which contribute to Hawaii鈥檚 goal of operating on 100% clean energy by 2045. But Phillips said Hawaii鈥檚 wind farms still have changes to make so that they’re operating in a way that minimizes negative impacts to endangered and threatened native species.
鈥淲e haven鈥檛 seen that happen with our wind farms yet,鈥 she said.
So far, nearly all of the money that Hawaii wind farm developers have invested in mitigation measures, as part of their habitat conservation plans, has funded research, Phillips said.
鈥淲hile it’s great to be able to learn more about the opeapea, it doesn’t mean that research is offsetting … the amount of bats that they’ve killed,鈥 she said. 鈥淪o it seems at this point that this decision by the Fish and Wildlife Service is definitely premature and counter to the best available science.鈥
One effective technique to reduce bat deaths, Phillips said, calls for wind farm developers to lock the turbine blades to stop them from spinning at night when wind speeds are low enough to permit the Hawaiian hoary bat to take to the sky. When wind speeds rise, the bats, which weigh as much as a mouse, can鈥檛 fly.
This technique, called wind speed curtailment, is something that wind developers have started to implement in Hawaii, Phillips said.
Another method that Kawailoa Wind Farm on Oahu has found promising, according to Phillips, is called acoustic deterrence, which involves emitting a noise that encourages bats to move away from the turbines.
But Phillips said researchers haven鈥檛 yet identified mitigation techniques that the wind farms can take to offset the bat deaths that still do occur.
And since the burden is on the violator of the Endangered Species Act to propose mitigation measures, Phillips said more work needs to be done to define these actions.
In the case of threatened and endangered seabirds that are prone to fall out of the sky after encountering bright artificial lighting, mitigation efforts might call for the violator to fence in a known seabird nesting colony to help protect the seabirds from predators.
There鈥檚 no equivalent mitigation measure for the Hawaiian hoary bat, Phillips said.
鈥淲e just don’t have that type of reliable information as it relates to the opeapea,鈥 she said. 鈥淪o none of the projects have been able to actually mitigate the (bat deaths) that they caused.鈥
The Hawaiian hoary bat first arrived in Hawaii 10,000 years ago after making an unlikely 2,500-mile journey from its North American origins.
The cryptic bat, with its foot-long wings, has evaded researchers for years due to its tiny size, its nocturnal, solitary nature and its ability to fly long distances in a single night.
The bats roost in tall treetops and female bats give birth once a year, usually to twins.
In 2015, the bat joined the Kamehameha butterfly, nene goose, humpback whale, humuhumunukunukuapuaa and Hawaiian monk seal in the exclusive club of official state animals. The goal of the designation was to raise public awareness of the threatened species.
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About the Author
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Brittany Lyte is a reporter for Civil Beat. You can reach her by email at blyte@civilbeat.org