Last month, Environment Hawai‘i reported on a new draft bat guidance document aimed at helping the state Endangered Species Recovery Committee (ESRC) make decisions regarding the Habitat Conservation Plans and Incidental Take Licenses that are required for wind farms to incidentally harm or kill protected species.
By all accounts, the original guidance document, adopted by the committee in 2015, is in sore need of updating. But according to comments submitted to the committee in February by wind farm representatives, the new draft sets unattainable standards that are not based on the best available science.
“Simply put, adoption and implementation of the draft updated guidance in its current form, including changes to bat-related mitigation, monitoring, and siting considerations, would impede development of new wind energy and lead to increased cost of power for state residents,” wrote Marilyn Teague of AEP Renewables in her February 19 comment letter on the draft guidance document, which was issued in January by the state Department of Land and Natural Resources’ Division of Forestry and Wildlife (DOFAW) and the ESRC.
AEP has an ownership interest in the Auwahi wind farm on Maui.
The state has passed legislation requiring that 100 percent of Hawai‘i’s electricity be generated from renewable sources by the end of 2045. Wind energy is considered by many to be key to reaching that goal, but in recent years, it has faced increasing opposition. Many existing facilities have killed far more endangered Hawaiian hoary bats than originally intended. And on North O‘ahu, protests, arrests, and legal actions have surrounded the construction of the Na Pua Makani wind farm, which community members have argued was built far too close to residences.
The draft guidance document seeks to at least deal with the bat concern. DOFAW administrator and ESRC chair Dave Smith said at an ESRC workshop in early March that he wanted more discussion to occur on the document, and that there was no timeline for when a final version would be approved. Given the comments received so far, it won’t be anytime soon.
Cost Prohibitive
One major criticism levied by Teague and other industry representatives is that the new draft guidance document proposes costly new monitoring and mitigation burdens.
Teague claims that if adopted by the ESRC, they would cost wind farms in Hawai‘i 400 percent more than it costs them to comply with current guidelines, “thus rendering future potential projects or repowering of existing projects economically infeasible.”
Eric Pendergraft, president of Na Pua Makani Power Partners, LLC, stated in his February 24 comment letter that the draft guidance’s adaptive management recommendations that would limit turbine operations to minimize bat take “would lead to commercial impacts that would prevent us from providing reliable power to our client.”
Also, based on a preliminary analysis of other proposed mitigative measures, he stated that his facility would need to install about 200 acoustic monitors, which “exponentially increases the cost to the operation.”
And that’s just the acoustic monitors.
Because research has found that acoustic monitors can fail to detect up to 75 percent of bats in a given area, the draft guidance recommends that wind farms supplement them with thermal monitors.
At an ESRC meeting in January, when asked by committee member Jim Jacobi whether she considered using thermal monitors, a consultant for the Pakini Nui wind farm on Hawai‘i island said she had not used them at the site because “the cost is prohibitive.”
Speaking to the need for both thermal and acoustic monitoring, ESRC member Melissa Price said at that meeting, “at the end of the day what really matters from a species perspective is, is this population stable or are you tanking it? Because of the actions that are taking place at this site and the only way to get at whether the overall population at your location is increasing or decreasing is with some sort of monitoring of the population and for bats that’s thermal and acoustic.”
With regard to mitigation, the draft guidance proposes that the minimum management area for each bat killed be increased from 40 acres to 97 acres. Teague and others have argued that this increase is not scientifically justified. She complained in her letter that the draft guidance relies on “the unjustified ~150 percent [core use area] increase to calculate a similarly unjustified research mitigation cost of $125,000 per bat.” Under the original guidance document, it was $50,000 per bat.
She argued that the mitigation value of research is tied to whether it contributes to the likelihood and extent of bat recovery. She added that the U.S. Fish and Wildlife Service, which also authorizes HCPs and incidental take permits, “has refused to accept bat research as mitigation. Unless the USFWS is willing to do so, and that willingness is reflected in the guidance, there is zero incentive for applicants to spend money on research. The guidance must clearly set forth the USFWS position on this issue.”
At the bat workshop in March, Michelle Bogardus of the Fish and Wildlife Service — who is also an ESRC member — said it was highly unlikely that her agency would accept research as mitigation for bat takes.
‘Impossible to Satisfy’
More so than the increased costs, the draft guidance’s proposed restriction on how much bat take should be allowed on a given island has the potential to kill future wind farm development, at least on O‘ahu.
The document suggests that until scientific evidence proves otherwise, it should be assumed that the bat population on O‘ahu is 1,000, on Maui it’s 1,500, and on Hawai‘i island it’s 5,000. It further recommends that additional bat take should not be authorized if cumulative take levels exceed the annual growth rate of the population on the island. For O‘ahu, preliminary modeling results included in the guidance suggested that the population might not be able to sustain take of more than 10 bats a year.
Teague and Tetra Tech, which consults for a number of local wind farms, have argued that those island population estimates are not scientifically justified. Teague also had this to say: “Although the draft updated guidance states that ‘population sizes are unknown, and it is generally accepted that it is not feasible at this point in time to ascertain an actual population estimate for a single island or the entire state,’ it calls for assessing project impacts on the species, and making permitting decisions based on population analyses, by (a) assuming that bat populations on each island are stable or slightly increasing (0 to 1 percent annual population growth), (b) assuming that compensatory reproduction from project mitigation does not occur, and (c) assuming that an annual rate of take that exceeds the annual rate of increase of a population is likely to cause a decline in the population. Of course, unless one knows the population in question, it’s not possible to determine whether projected take will exceed an assumed rate of population growth.”
Since the draft updated guidance assumes that it is not possible to produce any additional bats through mitigation, the standard that cumulative take not exceed the annual growth rate “is impossible to satisfy,” she added.
“In short, the draft updated guidance establishes a population-based test that has no scientific support and that is impossible to satisfy, meaning zero additional wind farms could be permitted in Hawai‘i,” she wrote.
Best Available Science
The comment letters on the draft guidance document were meant to inform discussion at an ESRC bat workshop held at the University of Hawai‘i at Manoa on March 5 and 6. A common complaint by industry representatives was that the guidance’s authors did not use the best available science.
With regard to the island population and growth trend estimates in the draft guidance, Theresa Menard, who undertook the modeling those estimates were based on, explained to workshop attendees, “This is our first effort at modeling Hawaiian hoary bats. More modeling is needed before relying heavily on this effort.”
ESRC member Jim Jacobi described it as a necessary first step, given that obtaining accurate population information of such as cryptic animal is going to be really hard to get.
A number of scientists who have been studying the bats over the past few years presented some of the results of their research, much of which was paid for by the wind farms as part of their bat take mitigation.
Researchers have found that the bats primarily eat moths, as well as a wide variety of termites. David Johnston of H.T. Harvey & Associates said that prey availability is likely a driving factor in the bats’ distribution. Still, he admitted, “I don’t think we have solid data to say this. Generally, this seems like it might be true. Much is still unknown about diet and foraging ecology.”
Even so, he recommended designing intact habitats featuring plants that attract the bats’ favorites foods. “I would advocate going down to the species level.” In his research on bat diets, “a common widespread moth in some habitats like grassland was eaten far more than any other moth. It’s a grass specialist. Then you can plant specific plants which will produce certain prey,” he said.
With regard to how much a bat needs to eat a night, Johnston said it depends on its energetic needs. “A lactating female may eat as much as her weight in a night,” he said.
“People assume the bats go out every night. … In fact, they do not. It may not go out because it’s made the decision it’s not worth foraging. I’m not going to put a reason on it. Bats are very complex animals. … Its need will change by season and by reproductive condition. Males and females have completely different needs.
“A male presumably could use much lower [insect] densities and get away with it, whereas a female might have to be much more efficient if she’s lactating,” he said.
The bats primarily reproduce in warm lowlands, look for big, shady trees to rear pups, and tend to use the smallest area that supports them, but will move if they have to, retired USGS bat expert Frank Bonaccorso said.
It’s well known that the bats give birth to twins, but, he continued, “We don’t know if they are more likely to successfully rear one or two. You can get into some misleading side tracks by using proxy data. But we don’t know. The best scientific data available is what we’ve got to work on.
“It’s a challenging bat. It is a more or less solitary rooster, and they roost very cryptically. Some are hole-nesters, or cave nesters, or live in human structures.”
Kristina Montoya Aiona, a master’s student at the University of Hawai‘i at Hilo, has taken the lead on some of the roost research being conducted by the USGS on Hawai‘i island. She described just how difficult it is to find where they go to sleep.
She and her team have been able to conduct 486 tracking events, following dozens of bats to dozens of roost stands and trees in East Hawai‘i.
“The level it takes to get to that, 486 tracking events, we usually have two teams of two personnel, eight to twelve to fourteen hours a day. It took about 150 personnel hours per roost, an incredible amount of effort to get to these roost trees and stands,” she said.
While the draft bat guidance document emphasizes management of native forest in mitigation efforts, Aiona said that ‘ohi‘a was the only native tree bats were seen in. Other roost tree species included eucalyptus, macadamia, lychee, mango, ironwood, and gunpowder.
Some bats had multiple roost locations. The mean height of roost trees was 21 meters. Mean perch height was 14 meters off the ground. And they tended to perch facing southward and westward. “I think it’s interesting. I don’t know quite what it tells us,” she said of the perch direction.
She did note that the tracking focused a lot in lowlands, along roads and hiking trails, because the teams were able to track the bats more efficiently. “In upland forest, it’s more difficult to track. I don’t want to have the takeaway be they’re not roosting up there. They are just more difficult to track there,” she said.
Jacobi asked her how much more effort it will take to have confidence to describe roost habitats and have them be used in management strategies.
“I hope this year we can at least double our numbers. For management, the takeaway for roosts is, we talk a lot about foraging habitat. Roosting habitat might not be the same thing,” she said.
Next Steps
It’s unclear how all of the latest research — and the industry’s comments — will be incorporated into the draft bat guidance document. But DOFAW’s Smith recognized the role the wind energy industry has played in generating that research.
“One of the things I say, tongue-in-cheek, I say ‘Wind energy is the best thing that’s ever happened to bats.’ … We were able to leverage a lot of resources from the companies. … Thirty years ago, we didn’t have anyone working on bats. [Today] we had nine people [from DOFAW] here focusing on this thing,” he said of the workshop.
“The goal for me is we make wind energy work and wind up with more bats in the process … I gotta believe we can do both,” he said.
ESRC member Price asked what the chances were of getting research that will answer questions about three key issues: population, population trends, and limiting factors.
One participant pointed out that the tools to observe bats are getting better. Researchers are able to sample longer and the tools to do so are getting cheaper. There are also new modeling techniques for converting some of the data already collected to “see if we can’t generate [bat] densities and basic extrapolations from that,” he said.
Michael Schirmacher of Bat Conservation International said managers on the mainland are facing the same problem there with assessing populations of hoary bats, which are also solitary roosters and vulnerable to strikes by wind turbines. At least Hawai‘i’s populations are restricted to islands, he said, adding “If you can’t do it here, you can’t do it anywhere.”
Johnston supported Smith’s sentiments about the industry partnership. “This has been a wonderful opportunity to move the science. Our map is much better. Our tools are smaller, cheaper, and better. … In the near future we [will have ability] to do much, much more,” Johnston said.
For future monitoring efforts, Smith said his agency is going to look island- by-island for projects that can allow for collaborative projects that will produce “better work for cheaper. … I really see a trend of things getting better.”
He said he hoped to convene similar scientific forums on bats, at least one in the next year.
(For more background, see our “Part 1” cover story in our April 2020 issue, “Draft Guidance Would Further Curb Number of Bats Wind Farms Can Kill.”)
— Teresa Dawson
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