Endangered Bat

Summary:  Champlin’s proposed mitigation would not benefit an individual bat or the Oahu bat population.  To meet State and Federal endangered species laws, they must be required to shut down the wind turbines at night to avoid killing more bats than their compensatory mitigation produces.

Wind Farm Low-Balling their Estimate of Endangered Bat Take:  The public is tired of Hawaii wind farms low-balling their calculations of anticipated mortality of endangered Hawaiian hoary bats then exceeding their incidental take permits/licenses within four or five years of their 20-plus-year operation periods and requesting amendments to up their authorized bat take.  To receive any incidental take permit/license, the applicant is supposed to address all anticipated project effects (during all years of operation) in a Habitat Conservation Plan.  Champlin’s Habitat Conservation Plan dramatically under-estimates their project’s anticipated bat mortality at 51 bats over 21 years by basing it on per-turbine bat take at Kahuku Wind Farm (where turbine blade rotor swept area is ½ the size of the proposed turbines (Figure 1), and where bat detections are very low, possibly due to the dry coastal location of that project) and by failing to include a buffer in case bat take is higher than anticipated.  See:  http://www.staradvertiser.com/2017/01/14/business/wind-farms-killing-more-bats-than-expected/

turbine size

Figure 1.  Illustration of the size of the large proposed Na Pua Makani Wind Turbine size in comparison to the existing Kahuku Wind Farm’s smaller turbines.

New Research Indicates Mitigation Does Not Work:  According to bat biologists, this may be because the bats were supported by the ungulate-related dung beetles and when they are gone, the bats don’t find as much food in the mitigation area.  When the existing permitted wind farms received their incidental take permits and licenses to kill bats (in 2012 and earlier), it would have been reasonable for the wildlife agencies to have considered that restoring native forest helps endangered bats.  Champlin is the first wind farm proposed since the new information about the ineffectiveness of bat mitigation became available.  After eleven years of industrial wind farm operations in Hawaii, there is no evidence a single bat has benefited from a wind farm mitigation project and it’s more likely mitigation is harming individual bats and bat populations.

To Avoid Killing Endangered Bats, Na Pua Makani Must Increase Low Wind Speed Curtailment:  Champlin proposes to minimize bat take by implementing low wind speed curtailment when wind speeds are 5 meters/second or lower at night (stopping blade spinning when winds are lighter because bats are flying under light wind conditions).  However, new research indicates the relatively large, strong-flighted Hawaiian hoary bats are still flying around wind turbines at existing North Shore wind farms up to wind speeds of 12 m/s (Figure 1, adapted from Gorresen et al 2015, Figure 19, p. 25 https://dspace.lib.hawaii.edu/bitstream/10790/2585/1/TR64_Gorresen_Bats_Final.pdf).

Gorresen bat wind speed explanationsFigure 2.  The relatively large, strong-flighted Hawaiian hoary bats are detected flying around wind turbines at existing North Shore wind farms (blue curve) at average wind speeds up to 12 meters/second.  By implementing low wind speed curtailment of 6.5 m/s (red arrows) instead of the proposed 5 m/s, Champlin could reduce bat take by 50%.  Low wind speed curtailment at 8 m/s would almost eliminate bat take.  Graph adapted from Gorresen et al 2015, Figure 19: https://dspace.lib.hawaii.edu/bitstream/10790/2585/1/TR64_Gorresen_Bats_Final.pdf

Avoidance of Bat Take Would Require Low Wind Speed Curtailment at 12 m/s average wind speed:  Because Champlin’s proposed mitigation fails to offset take of even one bat (as explained below), the wind developer must be required avoid bat take, which would entail low wind speed curtailment when wind speed averages 12 m/s or lower.

See video of contested case hearing addressing unlawful endangered species aspects of the project:  http://www.hawaiinewsnow.com/story/36083754/endangered-bat-at-center-of-fight-over-kahuku-wind-farm-proposal

Failure to Compensate for Bat Mortality:  Native Hawaiians, Polynesians, and the general public are fed up with Hawaii wind farms proclaiming that their take of bats will be offset by mitigation as required State’s “net benefit” requirement.  After eleven years of industrial wind farm operations in Hawaii, there is no evidence a single bat has benefited from a wind farm mitigation project and it’s possible mitigation is harming individual bats and bat populations.

Failure to assess bat abundance at proposed wind farm site or to use readily available data that suggests bat abundance may be higher at Champlin’s proposed wind farm site than the lowland Kahuku Wind Farm.  The Champlin HCP does not appear to incorporate acoustic monitoring data published in 2015.  Unless Champlin has conducted acoustic monitoring to inform bat occurrence at the proposed wind farm site, it seems reasonable to be concerned bat occurrence at the proposed wind farm site may be higher than bat occurrence at the Kahuku Wind Farm (Figure 1).

gorresen with wind farms

Figure 1.  From Gorresen et al (2015) Figure 4 Observed nightly bat detection probability by survey site as averaged for the 1-year acoustic survey period (white and blue are low probability, green, yellow, and red are higher bat occurrence sites, wind farm locations and labels added in purple).


Gorresen, P. Marcos, Paul M. Cryan, Manuela M. Huso, Cris D. Hein, Michael R. Schirmacher, Jessica A. Johnson, Kristina M. Montoya-Aiona, Kevin W. Brinck, and Frank J. Bonaccorso.  2015. Behavior of the Hawaiian hoary bat at wind turbines and its distribution across the north Ko‘olau Mountains, O‘ahu.  Hawai`i Cooperative Studies Unit University of Hawai`i at Hilo 200 W. Kawili St. Hilo, HI 96720 (808) 933-0706. https://www.researchgate.net/publication/277891159 (January 2015) and http://pubs.usgs.gov/circ/1367/ May 2015.  68 pp.

HCPs and Annual Reports, Cited by Wind Farm Name, are Available Online at:  http://dlnr.hawaii.gov/wildlife/hcp/approved-hcps/

*  Written by Dawn Bruns.  I am a North Shore resident, applying my math, science, and mapping skills to opposing this project on my weekends and periods outside work hours.  I present information I believe to be true based on my personal research as a member of the public and information compiled by collaborators and the various non-profit entities engaged in addressing the Champlin wind farm proposal.

** June 13, 2018 edit:  The findings and conclusions in this article are those of the authors and do not represent the official views of the U.S. Fish and Wildlife Service.