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Susitna-Watana Hydroelectric Project Document
ARLIS Uniform Cover Page
Title:
Wood frog distribution and habitat use
SuWa 177
Author(s) – Personal:
Author(s) – Corporate:
Alaska Energy Authority
AEA-identified category, if specified:
Wildlife resources study requests
AEA-identified series, if specified:
Series (ARLIS-assigned report number):
Susitna-Watana Hydroelectric Project document number 177
Existing numbers on document:
Published by:
[Anchorage] : Susitna-Watana Hydroelectric Project, [2012]
Date published:
5/16/2012
Published for:
Date or date range of report:
Volume and/or Part numbers:
Final or Draft status, as indicated:
Document type:
Pagination:
3 p.
Related work(s):
Pages added/changed by ARLIS:
Notes:
All reports in the Susitna-Watana Hydroelectric Project Document series include an ARLIS-
produced cover page and an ARLIS-assigned number for uniformity and citability. All reports
are posted online at http://www.arlis.org/resources/susitna-watana/
Susitna–Watana Hydroelectric Project, FERC # 14241 Alaska Energy Authority
Wood Frog Study Request, 5/16/2012 Page 1
1.1. Wood Frog Distribution and Habitat Use
1.2. Requester of Proposed Study
AEA anticipates resource agencies will request this study.
1.3. Responses to Study Request Criteria (18 CFR 5.9(b))
1.3.1. Describe the goals and objectives of each study proposal and the information to
be obtained.
The goal of the wood frog study is to characterize use of the Project area by wood frogs to
enable an assessment of potential impacts from development of the Project. The specific
objectives of the study are to synthesize existing habitat use and distribution data and to
evaluate the current distribution of wood frogs in the Project area through a combination of field
surveys and habitat occupancy modeling. This information (see Criterion 1.3.5 below) will be
used to estimate habitat loss and alteration for the species in the Project area.
1.3.2. If applicable, explain the relevant resource management goals of the agencies
and/or Alaska Native entities with jurisdiction over the resource to be studied.
[Please include any regulatory citations and references that will assist in
understanding the management goals.]
Concern has been expressed about the conservation status of wood frogs in Alaska (ADF&G
2006). Resource management agencies have devoted more attention to inventorying and
monitoring wood frog populations due to population declines of amphibians elsewhere in North
America and to reports of deformities in wood frogs elsewhere in Alaska (Anderson 2004).
1.3.3. If the requester is not a resource agency, explain any relevant public interest
considerations in regard to the proposed study.
Wildlife resources are owned by the State of Alaska, and the Project could potentially affect
these public interest resources.
1.3.4. Describe existing information concerning the subject of the study proposal, and
the need for additional information.
Amphibians were not included in the original Susitna Hydroelectric Project environmental
program studies in the 1980s; hence, data specific to the upper Susitna drainage is lacking. It is
likely that wood frogs occur in the Project area because they occur in suitable habitats
throughout southern Alaska and in the interior north to the southern slopes of the Brooks Range
and have been documented in Denali National Park and Preserve, near Healy, and in the lower
Susitna drainage (Cook and MacDonald 2003; Anderson 2004; Gotthardt 2004, 2005; Hokit and
Brown 2006; MacDonald 2010). Because concern has been expressed about the conservation
status of wood frogs in Alaska (ADF&G 2006) and their status in the Project area is unknown,
field surveys should be conducted in areas likely to be affected by Project facilities and
activities.
Susitna–Watana Hydroelectric Project, FERC # 14241 Alaska Energy Authority
Wood Frog Study Request, 5/16/2012 Page 2
1.3.5. Explain any nexus between project operations and effects (direct, indirect, and/or
cumulative) on the resource to be studied, and how the study results would
inform the development of license requirements.
For wood frogs, the Project will result in habitat loss and alteration, habitat fragmentation, and
direct mortality due to development activities. The wood frog study will provide data to assess
the following direct, indirect, and cumulative effects:
• Direct loss and alteration of wood frog habitats from Project construction and operation;
• Potential direct mortality due to Project-related fluctuating water and ice conditions in the
reservoir and downstream river reaches;
• Potential direct, indirect, and cumulative impacts on predator and prey abundance and
distribution related to habitat changes resulting from Project development.
The wood frog study would provide baseline data for the Project area, including habitat-use data
for development of habitat evaluation criteria. The study would provide a basis for impact
assessment; developing protection, mitigation, and enhancement (PME) measures; and
developing resource management and monitoring plans.
1.3.6. Explain how any proposed study methodology (including any preferred data
collection and analysis techniques, or objectively quantified information, and a
schedule including appropriate field season(s) and the duration) is consistent with
generally accepted practice in the scientific community or, as appropriate,
considers relevant tribal values and knowledge.
Ground-based auditory surveys of randomly selected waterbodies in the Project area would be
conducted in spring using standard methods (e.g., USGS 2010). These surveys involve auditory
detection of frogs calling during the breeding season to detect presence or absence of wood
frogs at each waterbody sampled. A repeated-measures survey design with pseudo-double-
blind-observations will be used to assess the accuracy of the auditory survey.
Habitat characteristics of each sampled waterbody (e.g., size and depth, presence of emergent
aquatic vegetation, presence of fish or beaver activity) would be recorded for each waterbody to
enable the development of an occupancy estimation model based on the habitat characteristics
of occupied waterbodies. Data from vegetation, wetland, and riparian habitat mapping, wetland
functional assessments, and the literature (e.g., Stevens et al. 2006) would be assessed as
potential model variables to characterize wood frog habitat. The model’s predictive accuracy
would be evaluated during subsequent field surveys. If the model is deemed reliable, it would be
used to classify all waterbodies in the Project area with respect to their probability of supporting
breeding wood frogs. Spatial analyses using model results then could be used to predict Project
impacts on wood frogs.
1.3.7. Describe considerations of level of effort and cost, as applicable, and why any
proposed alternative studies would not be sufficient to meet the stated
information needs.
Auditory surveys should be conducted in spring 2013 and 2014, requiring approximately 1–2
weeks of field surveys per year. Model development would be conducted during winter
2013/2014, and ground-truthing of the model would be done in the 2014 field season.
Susitna–Watana Hydroelectric Project, FERC # 14241 Alaska Energy Authority
Wood Frog Study Request, 5/16/2012 Page 3
Using a combination of field sampling and modeling would constrain costs compared with
attempting to census wood frogs in all waterbodies throughout the Project area. Field data from
auditory surveys are required, however, because a reliable wood frog habitat model cannot be
developed solely from the literature.
1.3.8. Literature Cited
ADF&G (Alaska Department of Fish and Game). 2006. Our wealth maintained: a strategy for
conserving Alaska’s diverse wildlife and fish resources. Juneau. 824 pp.
Anderson, B. C. 2004. An opportunistic amphibian inventory in Alaska’s national parks, 2001–
2003. Final report, National Park Service, Alaska Region Survey and Inventory Program,
Anchorage. 44 pp.
Cook, J. A., and S. O. MacDonald. 2003. Mammal inventory of Alaska’s national parks and
preserves: Denali National Park and Preserve. 2002 annual report for National Park
Service, Alaska Region Survey and Inventory Program, Anchorage, by Idaho State
University, Pocatello. 24 pp.
Gotthardt, T. 2004. Monitoring the distribution of amphibians in the Cook Inlet watershed: 2003
final report. Alaska Natural Heritage Program, University of Alaska, Anchorage.
Gotthardt, T. 2005. Wood frog conservation status report. Alaska Natural Heritage Program,
University of Alaska, Anchorage.
Hokit, D. G., and A. Brown. 2006. Distribution patterns of wood frogs (Rana sylvatica) in Denali
National Park. Northwestern Naturalist 87: 128–137.
MacDonald, S. O. 2010. The amphibians and reptiles of Alaska: a field handbook. Version 2.0.
University of Alaska Museum, Fairbanks, and Museum of Southwestern Biology,
Albuquerque, NM. Available online: http://aknhp.uaa.alaska.edu/wp-
content/uploads/2011/02/Herps-of-Alaska-Handbook-Final-Version-2-reduced.pdf
(accessed 3 March 2012)
Stevens, C. E., C. A. Paszkowski, and G. J. Scrimgeour. 2006. Older is better: Beaver ponds on
boreal streams as breeding habitat for the wood frog. Journal of Wildlife Management 70:
1360–1371.
USGS (U.S. Geological Survey). 2010. North American amphibian monitoring program protocol.
USGS Patuxent Wildlife Research Center, Patuxent, MD. Available online:
http://www.pwrc.usgs.gov/naamp/index.cfm?fuseaction=app.protocol (accessed 14 August
2011)