1. Colleen Henn, Sophia Huang, Eddie Kelinsky, and Ryan Suttle
BARRIERS TO WILDLIFE MIGRATION IN THE COYOTE VALLEY: YEAR TWO
Dept. of Environmental Studies & Sciences, Santa Clara University, Santa Clara Valley Open Space Authority
Introduction
The Coyote Valley is a 7400-acre area between San Jose and Morgan Hill in
California’s Silicon Valley. Not only does it serve as one of two critical
connections between the Santa Cruz Mountain Range and the Diablo Mountain
Range, but also it contains Silicon Valley’s last undeveloped groundwater
recharge area. Our study area has been deemed a biodiversity hotspot, with over
20 species of mammals and over 200 species of birds, including 21 species of
raptors (R. Phillips et al. 2008). This landscape and its surrounding mountain
ranges provide habitat to a myriad of rich biodiversity, including rare,
threatened, and endangered species, like the California Tiger Salamander and
American Badger. Working with the Santa Clara Open Space Authority, we are
seeking to create a more complete GIS database as well as to understand the
current and future options for wildlife corridor research and development.
US Highway 101 and Monterey Highway are two of the main barriers to
wildlife movement between the Santa Cruz and Diablo mountain ranges. The
effect of highly trafficked roads on animal populations can be seen in impacts
such as habitat loss and alienation, mortality from road kill, habitat
fragmentation, and sensory disturbance (Adams et al. 1983, Mansergh et al.
1989, Van der Zee et al. 1992). Our project is concerned with studying these
and other existing migration barriers, to assess the viability of potential new
corridors as well as improvements that could be done on current corridors, and
propose policy options to maintain and improve wildlife movement through
Coyote Valley.
1. What are the most commonly conceived barriers to wildlife migration?
2. What kind of attribute information would be helpful for researchers and
land managers in monitoring and improving corridors?
3. What are some next steps in improving corridor management and
maintenance in Coyote Valley?
Research Questions
Study Area
Methods
➢ Literature review of existing case studies to analyze common barriers and
successful solutions
➢ Interviewed eight stakeholders, including land managers and wildlife
ecologists to compile GIS information to create a more comprehensive
database
➢ Examined and categorized existing fence barriers with Google Earth Pro
➢ Improved upon existing GIS database by adding fence attributes:
approximate height, fence type, presence of barbed wire, and
transparency
➢ Analyzed policy solutions to preserve and maintain wildlife corridors
During the span of our project, we identified specific barriers to wildlife
migration in Coyote Valley. We improved details and attributes in the GIS
database for future use by researchers and land managers in the Valley. In
addition to consolidating habitat and infrastructure data, we classified fence
attributes (Figure 4) and identified and recommended a particular area of priority
on Highway 101, Monterey Highway, and Bailey Avenue for potential
directional fencing additions (Figure 3) based on a high concentration of roadkill
incidents due to high exposure and vulnerability during road crossings (Figure
1). Directional fencing would funnel wildlife towards nearby culverts so animals
may pass Highway 101 safely.
Policy Recommendations and Next Steps:
• Alter the zoning of the Upper- and Mid-Coyote Valley in the context of the
San Jose 2020 General Plan to include corridor guarantees via citizen
participation
• Continue improvement of GIS Database: actively monitor, locate and classify
culverts; update roadkill data; include sound pollution data and wildlife
sightings
• Mobilize and empower more local stakeholders, especially via town halls,
distribution of brochures to private landowners, and photographs of animal
usage of the corridor
Adams, Lowell W., and Aelred D. Geis. “Effects of Roads on Small Mammals”. Journal of Applied Ecology 20.2 (1983): 403–415.
Web.
Mansergh, Ian M., and David J. Scotts. “Habitat Continuity and Social Organization of the Mountain Pygmy-possum Restored by
Tunnel”. The Journal of Wildlife Management 53.3 (1989): 701–707. Web.
Noss, R. F. 1993. Wildlife corridors In D. S. Smith and R. C. Hellmund, eds. Ecology of Greenways. University of Minnesota Press,
Minneapolis, NM.
Phillips, R., T. Diamond, J. Phillips, P. Cornely, V. Jennings, and L. Morton. 2008. Coyote Valley Wildlife Corridor Monitoring
Program 2008 Annual Report. De Anza College, Cupertino, California.
Zee, F.f. Van Der, J. Wiertz, C.j.f. Ter Braak, R.c. Van Apeldoorn, and J. Vink. "Landscape Change as a Possible Cause of the
Badger Meles Meles L. Decline in The Netherlands." Biological Conservation 61.1 (1992): 17-22. Science Direct. Web.
Many thanks to the following stakeholders for contributions: Santa Clara University's Chris P. Bacon,
Jake Smith from the Open Space Preserve, Jodi McGraw from Jodi McGraw Consulting Services,
Morgan Grey from Berkeley, Neal Sharma from the Peninsula Open Space Trust, Ann Calnan from
Valley Transportation Authority, Tanya Diamond and Tony Nelson from Sonoma Land Trust, Kirk
Lenington from the Midpeninsula Regional Open Space District, and Dave Johnston from the
California Department of Fish and Wildlife
Acknowledgements
Figure 2. Known infrastructural barriers and
wildlife movement monitoring or observation
sites.
Figure 4. Four different fence types found in Coyote
Valley. Spatial data of fence types were created through
analysis using Google Earth Pro and ArcMap.
Findings
Geospatial Analysis:
References
Conclusions
Figure 3. High priority area along Hwy 101,
Monterey Hwy, and Bailey Ave due to high density
of roadkill observations. Directional fencing may
guide animals to nearby culverts and decrease
wildlife-vehicle collisions.
© Google Earth Pro
© Colleen Henn
© Colleen Henn
© Sophia Huang
Chainlink fence with barbed wire.
Horizontal wire fence.
Vertical wood board fence.
Example of ‘other’ category.
Figure 1. Coyote
crossing through traffic
on Bailey Avenue in the
heart of Coyote Valley.
© De Anza College