6 Wildlife

Hydroelectric projects potentially affect many aspects of aquatic and terrestrial wildlife communities, as outlined in the Project Effects Matrix (Part I).  Hydroelectric projects potentially affect habitat quality and quantity by altering lotic (stream) and lentic (reservoir) habitat, land disturbance, vegetation management, and noise disturbance from construction and maintenance activities.  A variety of approaches are discussed below to evaluate the effects of hydroelectric projects on:

  • Terrestrial habitat connectivity
  • Aquatic habitat connectivity
  • Avian collision and electrocution hazards
  • Instream flows and amphibian habitat


These are not all of the potential effects of hydroelectric projects on aquatic and terrestrial habitats, and the methods described in this section to evaluate them by no means cover all the potential approaches that could be used to study the effects.  Rather, this discussion focuses on those wildlife issues where a nexus to project effects is most distinct and where approaches to evaluate effects are not necessarily standardized.

Assessing project effects on the abundance and distribution of wildlife or to their habitat is typically conducted during the relicensing process, and the associated ESA and/or NEPA processes.  Basic approaches for inventorying the presence, distribution, and abundance of special-status wildlife species during the relicensing process typically involve the following steps:

Identify the potentially occurring special-status species in the area based on multiple data sources (e.g., USFWS, state fish and wildlife departments and local research stations).

  • Identify potential habitat for special-status species in the area based on review of aerial photographs or vegetation maps and field reconnaissance.
  • Select survey sites and conduct surveys for special-status species using a species-specific survey protocol.
  • Examples of wildlife survey protocols employed in some hydroelectric relicensings in the West for specific species or taxa are listed below.  The following Bureau of Land Management (BLM) website provides additional survey protocols: https://www.blm.gov/or/plans/surveyandmanage/sp.htm.


Mollusks and other Invertebrates

Furnish, J., T. Burke, T. Weasma, J. Applegarth, N. Duncan, R. Monthey, and D. Gowan. 1997. Survey protocol for terrestrial mollusk species from the Northwest Forest Plan. Draft Version 2.0 (October 29, 1997). USDA Forest Service and USDI Bureau of Land Management.  https://www.or.blm.gov/surveyandmanage/SP/Mollusks/tcover.htm.

Furnish, J., R. Monthey, and J. Applegarth. 1997. Survey protocol for aquatic mollusk species from the Northwest Forest Plan. Version 2.0 (October 29, 1997). USDI Bureau of Land Management.

USFWS (U. S. Fish and Wildlife Service). 1999. Conservation guidelines for the valley elderberry longhorn beetle. Revised report. USFWS, Sacramento Fish and Wildlife Office, Sacramento, California.


Amphibians and Reptiles

Seltenrich, C. P., and A. C. Pool. 2002. A standardized approach for habitat assessments and visual encounter surveys for the foothill yellow-legged frog (Rana boylii). Pacific Gas & Electric Company, San Ramon, California.

USFWS (U. S. Fish and Wildlife Service). 1997. U. S. Fish and Wildlife Service guidance on site assessment and field surveys for California red-legged frogs. USFWS, Sacramento Field Office, Sacramento, California.

Holland, D. C. 1991. A synopsis and status of the western pond turtle (Clemmys marmorata) in 1991. Prepared for the USFWS National Ecology Research Center, San Simeon, CA. Revised by Reese, D. A.



Pagel, J. E. 1992. Protocol for observing known and potential peregrine falcon eyries in the Pacific Northwest. Pages 83-96 in Proceedings of the symposium on peregrine falcons in the Pacific Northwest. Rogue River National Forest, Medford, Oregon.

USDA Forest Service. 1993. Protocol for surveying for spotted owls in proposed management activity areas and habitat conservation areas.  March 12, 1991 (Revised February 1993).

Quintana-Coyer, D. L., R. P. Gerhardt, M. D. Broyles, J. A. Dillon, C. A. Friesen, S. A. Godwin, and S. D. Kamrath. 2004. Survey protocol for the great gray owl within the range of the Northwest Forest Plan. Version 3.0. USDA Forest Service and USDI Bureau of Land Management, Portland, Oregon.



Zielinski, W. J., R. L. Truex, C. V. Ogan, and K. Busse. 1997. Detection surveys for fishers and American martens in California, 1989-1994. Pages 372-392 in G. Proulx, H. N. Bryant and P. M. Woodward, editors. Martes:  taxonomy, ecology, and management. Provincial Museum of Alberta, Edmonton, Alberta, Canada. https://www.fs.fed.us/psw/publications/documents/gtr-157/Chapter_1/Chapter_1.html