Bio
Dr. Dave Johnston is consulting ecologist and bat expert. He is a renowned wildlife ecologist and authority on bats and other small mammals of the western United States and Hawaii. Dr. Johnston has led bat research and bat and bird-related projects for more than 40 years. He has conducted and supervised hundreds of nesting bird, raptor, and owl surveys and avian fatality monitoring activities, helped develop avian and bat protection plans for renewable energy projects, and participated in fatality estimating and modeling efforts.
Dr. Johnston has conducted bat surveys for the U.S. Bureau of Land Management, The Nature Conservancy, National Park Service, Caltrans, California State Park system, and California Department of Fish and Wildlife. He guides public agencies and corporations in evaluating impacts and establishing mitigation for bat populations and is the senior author of California bat mitigation guidelines for Caltrans. Dr. Johnston has also led workshops on bat ecology and surveying methods for professionals through the U.S. Bureau of Land Management and the Wildlife Society, as well as for the public through California Academy of Sciences.
Prior to joining Integral Consulting, Dr. Johnston was an associate wildlife ecologist at H. T. Harvey & Associates where he worked for three decades.
Relevant Experience
Bats
Caltrans Bat Mitigation, Statewide, California — Served as lead author and project manager for California Bat Mitigation: Techniques, Solutions, and Effectiveness, a report developed for the California Department of Transportation that provided guidelines on effective mitigation for impacts on bats found on bridges. Completed the update of this document that provides protocols for surveying bats at bridges and includes the results of field surveys of bat mitigation projects for bridges throughout the state.
California Valley Solar Ranch, Carrizo Plain, California — Managed implementation of the avian and bat protection plan, fatality monitoring, and associated monitoring. Designed the details of how monitoring would occur on the ground and coordinated a power analysis to support the statistical validity of the monitoring approach.
Hearst Castle State Park Bat Mitigation Assistance, San Simeon, California — Wrote an innovative mitigation plan that included the mapping of tile roof areas occupied by bats and an exclusion plan that limited the potential impacts to the bat populations scattered throughout Casa Grande, the main house of the Hearst Castle State Park. Casa Grande needed re-roofing and several species of bats roosted under the tiles of the roof, and in several other areas throughout the property. An initial site assessment and a bat roost survey (pre-bid bat survey) was conducted by four H. T. Harvey & Associates bat biologists to provide guidance on the temporary humane exclusion of individual and colonial roosting bats under the roof tiles. This unique challenge of safely excluding bats before removing tiles was met by using ultrasonic sound generators that disturbed bats enough that they abandoned roosting areas so that the roofing contractor could remove tiles, reinforce the roof, and replace the same tiles back on the roof. The project evolved with additional monitoring for nesting birds and H. T. Harvey & Associates provided nesting bird deterrence until the project was completed.
Central Valley Flood Protection Plan, Conservation Strategy, and Feather River Regional Permitting Program, Central California — Wrote species accounts and mitigation sections for special status species of bats. H. T. Harvey & Associates provided leadership, technical expertise, and content while participating in numerous in-depth consultations with resource agencies and other stakeholders on behalf of and in coordination with the California Department of Water Resources. This process culminated in the release of the draft Central Valley Flood Protection Plan Conservation Strategy. As part of the development of the Conservation Strategy, H. T. Harvey & Associates prepared focused conservation plans for special-status, at-risk species. These plans are being used as guidance documents to help prioritize flood management projects and maintenance activities.
University of California, Santa Cruz Stormwater Improvements and On-Call Biological Services, Santa Cruz, California — As project manager and senior bat biologist, worked with the University of California, Santa Cruz to conduct surveys on the campus, including at the Lick Observatory. Conducted initial habitat assessments and roost exit counts to assess the presence of common and special-status roosting bats. Documented several roosting colonies, including a Mexican free-tailed bat maternity colony, and implemented avoidance and minimization measures.
Alma College Rehabilitation Project, Santa Clara County, California — Oversaw bat survey work for the project at Bear Creeks Redwoods Preserve. Assessed bat use of several abandoned structures at the preserve, before project implementation, employing a combination of acoustic monitoring and visual survey techniques to estimate the number of bats occupying the buildings, the species of bats, and the extent of their use of buildings.
Piedmont Stables Bat Management and Mitigation Plan, Piedmont, California — Led bat mitigation at Piedmont Stables for the East Bay Regional Park District. Developed and implemented a bat mitigation plan, which allowed for phased exclusion of bat so that the maternity colony moved through roosts and returned to their origin.
Anderson Dam Seismic Retrofit Project, Santa Clara County, California — Surveyed for nesting pallid bats near Anderson Dam in Santa Clara County and consulted with Valley Water on appropriate buffer zones for the project. H. T. Harvey & Associates has assisted Valley Water with numerous aspects of the Anderson Dam Seismic Retrofit Project. As the lead consultant addressing terrestrial (nonfish) biological resources for the project, H. T. Harvey & Associates has conducted surveys for special-status plants and wildlife; performed a delineation of regulated habitats; prepared the terrestrial biology section of the Draft and Final Environmental Impact Report; and worked on the regulatory permitting and agency coordination.
Caltrans A&E On-Call Professional and Technical Environmental Services Capell Creek Bridge Bat Mitigation, Napa County, California — Developed and led implementation for a bat mitigation plan for Capell Creek on Highway 128, which had three bat species living on it. Mitigation activities included developing methods to safely exclude bats and designing new habitats for a replacement bridge to provide maternity roosting habitat for those species displaced.
Bat Surveys for PG&E Topock Compressor Station Groundwater Remediation, San Bernardino County, California — As lead ecologist, managed Topock compressor station bat roost surveys and impact assessment project. Located roosting bats and bat colonies, for identifying appropriate best management practices and mitigation measures. Documented several colonies of roosting bats throughout project site and proposed mitigation measures to avoid and minimize project’s impacts on roosting bats and maternity colonies.
Plumas National Forest Pallid Bat Habitat Use Assessment, Plumas County, California — Served as lead bat biologist and project manager for Pallid bat Surveys for the Plumas National Forest that included acoustic surveys, mist netting surveys, and radio telemetry work to determine foraging and maternity roost locations.
Montezuma Hills Wind Resource Area Research, Solano County, California — Led bat efforts for the project. During two successive fall migration periods, compared three techniques used to detect the nocturnal activities of migrating bats and birds and to understand relationships between activity patterns and mortality. The monitoring and survey effort covered a total of 48 turbines at two energy facilities.
La Honda Creek Open Space Preserve Red Barn Bat Surveys, San Mateo County, California — Oversaw long-term monitoring of bats including pallid bats. Assessed bat use of the Red Barn at the preserve, and developed mitigation strategies and best management practices to conserve bats as this site was being planned as a high use area for the public.
Hawaiian Hoary Bat Surveys, Protocols, and Management, Hawaiian Islands — Led team that developed and tested survey methods for detecting the Hawaiian hoary bat during the summer maternity season, and designed monitoring and survey protocols and best management practices for a study for the Hawai‘i Forest Industries Association. The goal of the study was to develop scientifically sound and operationally practical procedures for surveying, monitoring, and avoiding impacts on endangered Hawaiian hoary bats during commercial forest harvest operations.
Kawailoa Wind Project, O’ahu, Hawai’i — Served as project manager and bat biologist. Statistically analyzed patterns between bat fatalities detected at the Kawailoa wind farm and the calls of the federally listed endangered Hawaiian hoary bat, as detected at the height of the wind turbine nacelles. Mist-netted and radio-tracked Hawaiian hoary bats across the project site and confirmed breeding by the species on Oahu, where it had not been documented previously.
Hawaiʻi Wildlife Action Plan and Forest Action Plan Update, Honolulu, Hawai’i — Contributed to updating wildlife-related content components of the State of Hawai‘i’s 2005 State Wildlife Action Plan (SWAP) and its 2010 Forest Action Plan (FAP). The team provided the biological expertise to update these plans on behalf of the Hawai‘i Department of Land and Natural Resources (DLNR). Tasks for SWAP included 1) writing new species accounts and updating existing accounts for terrestrial, aquatic, and marine species of greatest conservation need (SGCN); 2) updating the flora portion of the SWAP by revising the list of plant SGCNs; 3) researching and incorporating information on the vulnerability of sensitive species; 4) updating chapters on statewide, marine, and island conservation needs; 5) updating other portions of these comprehensive statewide plans. Tasks on FAP included updating Hawai‘i’s nine conservation and management issues of water quality and quantity, forest health, wildfire, urban and community forestry, climate change, native biodiversity, nature-based recreation, forest products, and tropical island state and territory issues.
U.S. 101 Highway Improvement Project, Santa Clara County, California — As a senior wildlife biologist, surveyed for roosting bats at many bridges along the project alignment, prepared Natural Environment Study sections addressing bat impacts and mitigation, and coordinated with CDFW staff regarding bat issues for improvements to U.S. 101 from Gilroy south to State Route 129, a Caltrans and VTA project.
Habitat Conservation Planning and Monitoring of Seabird Fallout at Airports and Harbors, Kaua‘i, Maui, and Lāna‘i, Hawai‘i — Serves as senior bat biologist, helping the Hawai‘i Department of Transportation obtain up-to-date information on the occurrence of sensitive species, particularly Endangered Species Act-listed seabirds, at its harbors and airports on the islands of Kaua‘i, Maui, and Lāna‘i. The team developed and implemented a monitoring program to assess the fallout of seabirds; provided technical assistance and species expertise to facilitate completion of the Kaua‘i Seabird Habitat Conservation Plan (HCP) and are drafting and processing the Maui Seabird HCP; trained biologists to conduct facility-wide monitoring surveys to document and rescue seabirds; and designed and implemented monitoring protocols for detecting endangered Hawaiian hoary bat acoustic activity.
Altamont Pass Wind Resource Area Wildlife Management, Central California — Served as senior technical advisor and bat expert for post-construction bat and bird fatality monitoring at NextEra’s Golden Hills and Golden Hills North wind-energy facilities in the Altamont Pass Wind Resource Area. Assisted with project management and provided technical expertise in bat biology for three years of fatality searches.
Ivanpah Solar Electric Project, California — Managed post-construction bat and bird fatality monitoring and developed a successful bat deterrent strategy for the Ivanpah Solar Electric Generating System in southern California. Assisted in gaining Technical Advisory Committee (TAC) approval of the Avian and Bat Fatality Monitoring Plan for the Ivanpah Solar Energy Project operated by NRG Energy. Coordinated closely with U.S. Geological Survey during its site study and led insect exposure assessments. Oversaw seasonal and yearly fatality estimate calculations and presented results during TAC meetings.
Alum Rock Park Project, San Jose, California — Surveyed for California red-legged frog, steelhead, and bats. Recorded and moved more than 500 south central evolutionarily significant units of steelhead and provided innovative mitigation for two maternity colonies of bats that allowed bats to remain in roosts while construction proceeded.
San Mateo County Bat Projects, California — Served as project manager or senior bat biologist for several bat-related projects in San Mateo County including bat mitigation for Townsend’s big-eared bats and Yuma myotis for the San Francisco Water and Power Department for the Chrystal Springs/San Andreas Pipeline Repair Project and conducted bat surveys and developed mitigation strategies for bats at several private estates including the Villa Lauriston in Portola Valley. For the Santa Clara County Water District, performed trapping surveys for SMHM, evaluated species’ distribution in many South Bay creeks and sloughs, and made recommendations for Reach 1A management.
PG&E Pit 3, 4, 5 Project, Shasta County, California — As project manager and lead bat biologist for the PG&E Pit 3, 4, 5 Project for the FERC Licensing Process. Conducted bat surveys for Pit powerhouses and dams 3, 4, and 5 along the Pit River and suggested appropriate best management practices to reduce potential impacts to roosting bats.
Salt Marsh Harvest Mouse
Santa Clara Valley Water District Master Biological Services On-Call Agreement, Santa Clara County, California — Conducted surveys and prepared reports for the salt marsh harvest mouse, recommended and supervised implementation of measures to avoid take of salt marsh harvest mouse. Conducted surveys for bats and special status species of mammals (e.g., San Francisco dusky-footed woodrats) and made recommendations to mitigate impacts. H. T. Harvey & Associates conducted on-call work for the Santa Clara County Water District involving more than 130 task orders under four consecutive contracts.
Dixon Landing Road Interchange Project, Fremont, California — Surveyed and trapped for salt marsh harvest mice for the project’s salt marsh harvest mouse exclusion trapping phase. The project included the assessment of the impacts on wildlife of a proposed interchange at Dixon Landing Road and I-880. The mitigation planning for this project led to the preparation of feasibility studies for up to 19 acres of salt marsh habitat restoration at a variety of sites. The project included assessment of the impacts on wildlife of a proposed interchange. The mitigation planning led to preparation of feasibility studies for up to 19 acres of salt marsh habitat restoration at a variety of sites.
South Bayside Outfall Pipe Emergency Repair, Redwood City, California — Served as wildlife biologist on a project to recommend, undertake, and supervise the implementation of measures to avoid take of salt marsh harvest mice and Ridgway’s rail during emergency repair of the South Bayside System Authority’s outfall pipe to San Francisco Bay. Participated in salt marsh harvest mouse surveys, contributed expertise to the team that developed and obtained USFWS approval of measures to avoid take, and assisted in implementing these measures during repair activities.
Solar
California Valley Solar Ranch, Carrizo Plain, California — Managed implementation of the avian and bat protection plan, fatality monitoring, and associated monitoring. Designed the details of how monitoring would occur on the ground and coordinated a power analysis to support the statistical validity of the monitoring approach.
Ivanpah Solar Electric Project, California — Managed post-construction bat and bird fatality monitoring and developed a successful bat deterrent strategy for the Ivanpah Solar Electric Generating System in southern California. Assisted in gaining Technical Advisory Committee (TAC) approval of the Avian and Bat Fatality Monitoring Plan for the Ivanpah Solar Energy Project operated by NRG Energy. Coordinated closely with U.S. Geological Survey during its site study and led insect exposure assessments. Oversaw seasonal and yearly fatality estimate calculations and presented results during TAC meetings.
Renewable Energy
Montezuma Hills Wind Resource Area Research, Solano County, California — Led bat efforts for the project. During two successive fall migration periods, compared three techniques used to detect the nocturnal activities of migrating bats and birds and to understand relationships between activity patterns and mortality. The monitoring and survey effort covered a total of 48 turbines at two energy facilities.
Altamont Pass Wind Resource Area Wildlife Management, Central California — Served as senior technical advisor and bat expert for post-construction bat and bird fatality monitoring at NextEra’s Golden Hills and Golden Hills North wind-energy facilities in the Altamont Pass Wind Resource Area. Assisted with project management and provided technical expertise in bat biology for three years of fatality searches.
Education & Credentials
Highlights
More than 40 years of experience
Bat studies, conservation, and mitigation
Bird and bat fatality estimation
Wildlife and avian ecology
Renewable energy
Education & Credentials
Ph.D., Biology, York University, Toronto, Ontario, Canada, 1997
M.A., Biological Sciences, San José State University, San José, California, 1978
B.S., Biology, California State University, San Luis Obispo, California, 1974
CDFW Scientific Collecting Permit for amphibians, reptiles, fishes, invertebrates, mammals, including bats (SC-004098)
Professional Experience
Associate, H. T. Harvey & Associates, 1996–July 2026
Executive director, Youth Science Institute, 1979–1995
Professional Affiliations
Board member of the North American Society for Bat Research, 2013–2016
American Society of Mammalogists – Life Member
Western Bat Working Group, Vice President, 2012–2014
Appointed member of the Altamont Pass Wind Resource Science Advisory Committee for a Habitat Conservation Plan for 2 years