Important definitions, and some links and resources of interest to you!

Impacts and Mitigation

If potential roosting habitat is first evaluated during “pre-construction surveys” shortly before the start of construction, it may be too late to appropriately mitigate impacts and projects may experience significant delays. “Pre-construction surveys for roosting bats” should not be the first requirement of a mitigation measure.

Habitat assessments should be performed first during the project planning stage to determine if roosting habitat occurs in a project area. Habitat assessments should be conducted by a biologist with significant knowledge of bat roosting ecology in California.

Impact assessments and mitigation are site- and project-specific. They may require studies to determine habitat use patterns (e.g., seasons of use, type of roost, species, numbers). Conducting habitat assessments during the planning stage allows time to determine potential project impacts, and to develop more efficient and effective mitigation approaches (e.g., construction timing) if roosting habitat is found.

Pre-construction surveys should be used to confirm prior conclusions, not as the first effort to assess habitat and determine project impacts. Pre-construction surveys should be considered a final effort before construction impacts occur (e.g., confirm that a roost is vacant).

Conducting a timely bat habitat assessment and requiring appropriate mitigation measures informed by the best available bat ecology knowledge allows for better biological outcomes and reduces the likelihood of unexpected project delays.

CBWG Guidance Document - Bats in Swallow Nests

Year-round occupancy of cliff swallow mud-nests by several bat species has been observed throughout California, but formal documentation of these observations is limited to project reports. Peer-reviewed publications on this topic are lacking. Bats roosting in cliff swallow mud-nests will be subject to direct impacts if they are present when these nests are removed to prevent swallows from nesting. In the document attached below we compile records from working group members to share information on bat roosts in cliff swallow mud-nests and provide CBWG recommendations for take avoidance, including nest inspections and habitat modification to discourage occupancy.

Bats in Swallow Nests

Used Survey Equipment Marketplace

Click here to visit the classified section of our working group! If you are interested in selling, buying, or renting out your used equipment, check it out.

Conservation Websites

Western Bat Working Group

The Western Bat Working Group consists of agencies, organizations and individuals passionate about bat research, management and conservation from fifteen western states (including us here in California); the provinces of Alberta, British Columbia and Saskatchewan; the Northwest and Yukon territories and northern Mexico.

Bat Conservation International – BCI

The mission of Bat Conservation International is to conserve the world’s bats and their ecosystems to ensure a healthy planet.

Bat Wiki

This bat wiki of information is run by the North American Bat Conservation Alliance to allow members of the bat conservation community to share and discuss practices to mitigate threats facing bats in North America (Canada, USA and Mexico)

Bat Acoustic Monitoring Portal

The place to archive and visualize bat monitoring datasets generated from any type of acoustic detector or species identification process.

Climbers for Bat Conservation

Climbers for Bat Conservation aims to better understand and conserve bat populations by building connections with rock climbers, land managers, and biologists.

White-nose Syndrome

White-nose Syndrome Information

White-nose syndrome is a disease affecting hibernating bats. Named for the white fungus that appears on the muzzle and other parts of hibernating bats, WNS is associated with extensive mortality of bats in eastern North America. This site offers extensive resources and latest news about the spread of the disease.

Fight White-nose Syndrome is a charity that strives to educate others on the value and beauty of North American bat species, and financially contribute to the fight against and understanding of white-nose syndrome