Ecology of Foothill Yellow-Legged Frog

Ecology of Foothill Yellow-Legged Frog program image

Due to the ongoing public health crisis, this date is a place holder. We would like to offer the workshop when conditions are safe for people to gather in groups, but unfortunately, we don't know when that will be.


Tuesday, September 1, 2020
8:00 AM - 6:00 PM
Sunol Ohlone Regional Wilderness
Lunch will be provided



COST: $0.00
Payable by check to Elkhorn Slough Foundation
Payable by credit card (online)

CLASS SIZE: 30 Details for this workshop have not yet been finalized.

Instructor Information

Steve Bobzien
Ecological Services Coordinator
East Bay Regional Park District

Marcia Grefsrud
Environmental Scientist
California Department of Fish & Wildlife

Dr. Sarah Kupferberg
Independent Scholar and Consulting Ecologist


Grant Lyon



See also: Foothill Yellow-Legged Frog, Habitat Restoration

Workshop Description


Sarah Kupferberg, Ph.D., Steve Bobzien, and Marcia Grefsrud will present this workshop on the biology and conservation of the Foothill Yellow-legged Frogs (FYLF) at the Sunol Ohlone Regional Wilderness of the East Bay Regional Park District. Dr. Kupferberg has published a wide variety of papers on the ecology and life history of FYLF, and developed previous workshop presentations on the species for the Wildlife Society and the California Department of Fish and Wildlife Conservation Lecture Series. Marcia Grefsrud, a 23-year veteran of the California Department of Fish & Wildlife, has been conserving habitat and overseeing permits in Alameda County since 2005, and collaborating with Steve and Sarah on stream surveys and chytrid outbreak monitoring in Alameda Creek since 2012. Steve Bobzien is a wildlife ecologist and has been with East Bay Regional Park District for over 25 years. He is the principle research investigator on aquatic breeding amphibians and the primary author of a comprehensive study on the status of the California tiger salamander, California red-legged frog, foothill yellow-legged frog and other aquatic herpetofauna in the East Bay Regional Park District. 


The classroom portion of this workshop includes digital presentations by Dr. Kupferberg on the identification, life history, population biology, conservation, diseases and parasites of FYLF. Mr. Bobzien will discuss the long term monitoring conducted in Alameda Creek. Ms. Grefsrud will discuss management and regulatory considerations related to the recent listing of FYLF under the California Endangered Species Act. Presentations will be interspersed with discussion and small group exercises focused on tadpole identification.


The field portion of the workshop will include hands-on training on habitat assessment and survey techniques as well as in situ discussion about management . Specifically we will focus on stream channel morphology and the physical conditions preferred by FYLF as well as assessing the invasive species that are predators and competitors of FYLF. FYLF are present in Alameda and we anticipate that participants will be able to observe FYLF behavior and handle the species with supervision. However, we cannot guarantee handling or in-stream wading due to the stochastic nature of planet Earth’s biota as well as potential for failure of human systems beyond our control. Participants will need rubber boots or waders (hip or chest waders with no holes) to wade or walk along the stream margins.


The workshop fee includes classroom sessions and field time on June 3, 8:00-6:30, in Alameda Creek, at the Sunol Ohlone Regional Wilderness, 6 miles southeast of Calaveras Road exit on Hwy 680. Fee also includes coffee, lunch, refreshments, and handouts. 


Workshop Objectives


To increase participant understanding of

  • the biology of Foothill Yellow-Legged Frog;
  • the latest research on the species;
  • habitat management for the species, and;
  • how to apply information in conservation planning efforts


Improve these participant skills

  • species identification;
  • aquatic habitat sampling techniques, and;
  • stream site assessment


Topics Addressed


  • Rana boylii life history and natural history, breeding, rearing and adult habitat requirement
  • Basic genetics and evolutionary history of Rana boylii
  • Instruction on how to identify all stages of Rana boylii
  • Recommended sampling methods and seasons for detecting different life history stages - specifically detailing CDFG sampling guidance
  • Permitting requirements for work with Rana boylii
  • Interactions of Rana boylii with other species
    • ​Tadpoles: Role of periphyton food, predators, and temperature in determining recruitment success
    • Juveniles and adults: Invertebrate prey and and vertebrate predators
    • Fish vs. frog management conflicts
  • Demography and population dynamics of Rana boylii
  • Risk Factors associated with Rana boylii decline
    • ​Flow management (Dams' and diversions' effects on discharge timing and magnitude, temperature, channel shape, etc.)
    • Invasive species (bullfrogs, crayfish, non-native predatory fish)
    • Chytrid fungus and other diseases /parasites
  • Habitat restoration and reintroduction efforts
  • Frog friendly in-stream flow management and discussion  of minimization measures that limit impacts of in-stream construction projects


Field Training Practicum


Participants will receive skills-based training in species identification, visual encounter survey, time-constrained, and area-constrained survey techniques. Sarah, Steve, and Marcia will lead participants on walks through stream reaches with varying densities of Foothill Yellow-legged Frogs to compare habitat attributes and risk factors affecting the frogs. A hands-on skill building exercise for site assessment relevant to conserving the species will be done.


***Important information***


It is important to note that no component of this workshop should be construed to apply to attendees’ ability to obtain permits related to the FYLF; if you are interested in how workshop activities might be used for permitting, you are encouraged to contact your agency permitting representative.


Registration details


Please note - you can pre-register via this website, but your registration will not be finalized until we receive your registration fee of $. Payment can be either in the form of a credit card or a check made payable to the Elkhorn Slough Foundation and sent to:


Elkhorn Slough Foundation

ATTN: Coastal Training Program

1700 Elkhorn Road

Watsonville, CA 95076


Deadline for payment is 5 p.m. Wednesday, May 6, 2020.  If we have not received your payment at that time, your place may be forfeit to someone on our waiting list. 

We will refund cancellations prior to May 6 minus a $50 processing fee; we cannot refund any fees after that date. We reserve the right to cancel the workshop prior to May 8, 2020; in that event, we will give full refunds.

We ask you not to cancel after the registration deadline; if you sign up, please show up so as to not waste valuable resources. Repeated failure to adhere to these policies may jeopardize a person’s future ability to enroll in our programs.

We do not allow third party registration- register only yourself!  Registration is email sensitive; registering others frequently results in cancellation, missed communication, and other issues.

Because large, wealthy organizations have in the past reserved large blocks of seats, excluding others from attending, only to cancel those reservations, we do not allow registration 'trading,' even to persons within the same organization.

Documents and Publications

Contact List
We encourage participants to download the contact list to assist with arranging a rideshare or to get in contact with someone you met at the workshop. Those interested in sharing a ride to the event are marked on the contact list.

Amphibian Chytrid (Batrachochytrium dendrobatidis) in Post-Metamorphic Rana boylii in Inner Coast Ranges of Central California
PDF, 265KB
Lowe, J.
Herpetological Review 40(2):180-182
Amphibian Orientation: An Unexpected Observation
PDF, 446KB
Twitty, V., D. Grant, and O. Anderson
Science 155(3760:352-353
Amphibians and Reptiles of the Rogue River Basin, Oregon
Fitch, H. S.
American Midland Naturalist 17(3):634-652
May 1936
Batrachochytrium dendrobatidis, a novel pathogen approaching endemism in central California
PDF, 1.1MB
Padgett-Flohr, Gretchen E and Hopkins II, Robert L
Diseases of aquatic organisms
Bullfrog (Rana Catesbeiana) Invasion of a California River: The Role of Larval Competition
PDF, 554KB
Kupferberg, S. J.
Ecology 78(6):1736-1751
Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii
PDF, 128KB
Sparling, D. W. and G. Fellers
Environmental Pollution 147:535-539
Consequences of dam-altered thermal regimes for a riverine herbivore’s digestive efficiency, growth and vulnerability to predation
PDF, 956KB
Catenazzi, A. and S. J. Kupferberg
Freshwater Biology 00:1-12
Decline of Ranid Frog Species in Western North America: Are Bullfrogs (Rana catesbeiana) Responsible?
PDF, 542KB
Marc P. Hayes and Mark R. Jennings
Journal of Herpetology, 20(4):490-509
Diets of Three Species of Anurans from the Cache Creek Watershed, California, USA
PDF, 535KB
Hothem, R. L., A. M. Meckstroth, K. E. Wegner, M. R. Jennings, and J. C. Crayon
Journal of Herpetology 43(2):275-283
Dynamic Flow Modelling of Riverine Amphibian Habitat with Application to Regulated Flow Management
PDF, 1.6MB
Yarnell, S. M., A. J. Lind, and J. F. Mount
River Res. Applic.
Ecogeography of the herpetofauna of a northern California watershed: linking species patterns to landscape processes
PDF, 200KB
Welsh Jr H. H., G. R. Hodgson, and A. J. Lind
Ecography 28:521-536
Effects of carbaryl on species interactions of the foothill yellow legged frog (Rana boylii) and the Pacific treefrog (Pseudacris regilla)
PDF, 530KB
Kerby, J. L. and A. Sih
Hydrobiologia 746:255-269
Effects of Flow Regimes Altered by Dams on Survival, Population Declines, and Range-Wide Losses of California River-Breeding Frogs
PDF, 839KB
Kupferberg, S. J., W. J. Palen, A. J. Lind, S. Bobzien, A. Catenazzi, J. Drennan, and M. E. Power
Conservation Biology 26(3):513-524
Effects of Introduced Bullfrogs, Rana catesbeiana, on the Native Frogs of the San Joaquin Valley, California
PDF, 152KB
Peter B. Moyle
COPEIA, 1:18-22
Effects of water temperature on breeding phenology, growth, and metamorphosis of foothill yellow-legged frogs (Rana boylii): A case study of the regulated mainstem and unregulated tributaries of California's Trinity River
PDF, 790KB
Wheeler, C. A., J. B. Bettaso, D. T. Ashton, and H. H. Welsh Jr
River Res. Applic.
Extreme drought, host density, sex, and bullfrogs influence fungal pathogen infection in a declining lotic amphibian
PDF, 3.9MB
Adams, A. J., S. J. Kupferberg, M. Q. Wilber, A. P. Pessier, M. Grefsrud, S. Bobzien, V. T. Vredenburg, and C. J. Briggs
Ecosphere 8(3):e01740
March 2017
Facilitation of periphyton production by tadpole grazing: functional differences between species
PDF, 819KB
Kupferberg, S. J.
Freshwater Biology 37:427-439
Factors that Influence the Timing of Calling and Oviposition of a Lotic Frog in Northwestern California
PDF, 1.9MB
Wheeler, C. A., A. J. Lind, H. H. Welsh Jr, and A. K. Cummings
Journal of Herpetology 52(3):289-298
Fine-Scale Genetic Structure in the Threatened Foothill Yellow-Legged Frog (Rana boylii)
PDF, 218KB
Dever, J. A.
Journal of Herpetology 41(1):168-173
Food Habits of Triturus Granulosus in Western Oregon
PDF, 135KB
Evenden, Jr., F. G.
Copeia 1948(3):219-220
Foothill Yellow-Legged Frog (Rana boylii) Oviposition Site Choice at Multiple Spatial Scales
PDF, 730KB
Lind, A. J., H. H. Welsh Jr., and C. A. Wheeler
Journal of Herpetology 0(0):000-000
Hydrologic and Geomorphic Factors Affecting Conservation of a River- Breeding Frog (Rana Boylii)
PDF, 1.9MB
Kupferberg, S. J.
Ecological Applications 6(4):1332-1344
Isolation of peptides of the brevinin-1 family with potent candidacidal activity from the skin secretions of the frog Rana boylii
PDF, 231KB
Conlon, J. M., Sonnevend, A ́., Patel, M., Davidson, C., Nielsen, P. F., Pa ́l, T. and Rollins-Smith, L. A.
J. Peptide Res. 62:207-213
Late-Summer Aggregation of the Foothill Yellow-Legged Frog (Rana boylii) in Central California
Leidy, R. A., Gonsolin, E., and G. A. Leidy
The Southwestern Naturalist 54(3)370-371
Linking the distribution of an invasive amphibian (Rana catesbeiana) to habitat conditions in a managed river system in Northern California
PDF, 594KB
Fuller, T. E., K. L. Pope, D. T. Ashton, and H. H. Welsh Jr.
Restoration Ecology
Mating Strategy and Breeding Patterns of the Foothill Yellow-legged Frog (Rana boylii)
PDF, 1.1MB
Wheeler, C. A. and H. H. Welsh Jr
Herpetological Conservation and Biology 3(2):128-142
Modeling potential river management conflicts between frogs and salmonids
PDF, 656KB
Railsback, S. F., B. C. Harvey, S. J. Kupferberg, M. M. Lang, S. McBain, H. H. Welsh Jr
Can. J. Fish. Aquat. Sci. 73:773-784
Novel aspects of oviposition site preparation by foothill yellow-legged frogs (Rana boylii)
Rombough, C. J. and M. P. Hayes
Northwestern Naturalist 86:157-160
Ontogenic changes in foraging behaviour and habitat use by the Oregon garter snake, Thamnophis atratus hydrophilus
PDF, 620KB
Lind, A. J. and H. H. Welsh Jr.
Animal Behaviour 48:1261-1273
Parasitic Copepod (Lernaea cyprinacea) Outbreaks in Foothill Yellow-legged Frogs (Rana boylii) Linked to Unusually Warm Summers and Amphibian Malformations in Northern California
PDF, 1.1MB
Kupferberg, S. J. A. Catenazzi, K. Lunde, A. J. Lind, and W. J. Palen
Copeia 3:529-537
Population genomic data reveal extreme geographic subdivision and novel conservation actions for the declining foothill yellow- legged frog
McCartney-Melstad, E., M. Gidis, and H. B. Shaffer
Heredity 121(2):112-125
Rana boylii in Oregon
PDF, 208KB
Fitch, H. S.
Copeia 1938(3):148
September 1938
Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): implications for the conservation of frogs and rivers
PDF, 526KB
Lind, A. J., P. Q. Sparks, G. M. Fellers, and H. B. Shaffer
Conserv Genet 12:269-284
Rapid extirpation of a North American frog coincides with an increase in fungal pathogen prevalence: Historical analysis and implications for reintroduction
PDF, 861KB
Adams, A.J., A. P. Presser, and C. J. Briggs
Ecology and Evolution 7:10216-10232
Responses of Foothill Yellow-legged Frog (Rana boylii) Larvae to an Introduced Predator
PDF, 894KB
Paoletti, D. J., D. H. Olson, and A. R. Blaustein
Copeia 1:161-168
Spatial relationships in a dendritic network: the herpetofaunal metacommunity of the Mattole River catchment of northwest California
PDF, 748KB
Welsh Jr, H. H. and G. R. Hodgson
Ecography 33:1-18
Spatial relationships in a dendritic network: the herpetofaunal metacommunity of the Mattole River catchment of northwest California
PDF, 276KB
Welsh Jr, H. H. and G. R. Hodgson
Ecography 34:49-66
Spatial Tests of the Pesticide Drift, Habitat Destruction, UV-B, and Climate-Change Hypotheses for California Amphibian Declines
PDF, 3.8MB
Carlos Davidson, H. Bradley Shaffer, and Mark R. Jennings
Conservation Biology, 16(6):1588-1601
The Effects of a Dam on Breeding Habitat and Egg Survival of the Foothill Yellow-legged Frog (Rana boylii) in Northwestern California
PDF, 439KB
Lind, A. J., H. H. Welsh Jr., and R. A. Wilson
Herpetological Review 27(2):62-67
The importance of thermal conditions to recruitment success in stream-breeding frog populations distributed across a productivity gradient
PDF, 1.4MB
Catenazzi, A. and S. J. Kupferberg
Biological Conservation 168:40-48
The influence of relative sediment supply on riverine habitat heterogeneity
PDF, 873KB
Yarnell, S. M., J. F. Mount, and E. W. Larsen
Geomorphology 80:310-324
The perils of unpalatable periphyton: Didymosphenia and other mucilaginous stalked diatoms as food for tadpoles
PDF, 991KB
Furey, P. C., S. J. Kupferberg, and A. J. Lind
Diatom Research
The role of larval diet in anuran metamorphosis
PDF, 2.1MB
Kupferberg, S. J.
Amer. Zool. 37:146-159
The Yellow-Legged Frog, Rana boylii, from the Sierra San Pedro Mártir, Baja California Norte, México
PDF, 159KB
Loomis, R. B.
Herpetologica 21(1):78-80
Thermal control of aggregation behavior in tadpoles
Brattstrom, B. H.
Herpetologica 18(1):38-46
Toxicity of two insecticides to California, USA, anurans and its relevance to declining amphibian populations
Sparling, D. W., and G. M. Fellers
Environmental Toxicology and Chemistry 28(8):1696-1703
Transferability of habitat suitability criteria for a stream breeding frog (Rana boylii) in the Sierra Nevada, California
PDF, 923KB
Bondi, C. A., S. M. Yarnell, and A. J. Lind
Herpetological Conservation and Biology 8(1):88–103
Underwater vocalization by the foothill yellow-legged frog (Rana boylii)
PDF, 223KB
MacTague, L. and P. T. Northen
Transactions of the Western Section of the Wildlife Society 29:1-7
Variation in thermal niche of a declining river-breeding frog: From counter-gradient responses to population distribution patterns
Catenazzi, A. and S. J. Kupferberg
Freshwater Biology 00:1-11
Water Velocity Tolerance in Tadpoles of the Foothill Yellow-legged Frog (Rana boylii): Swimming Performance, Growth, and Survival
PDF, 513KB
Kupferberg, S. J., A. J. Lind, V. Thill, and S. M. Yarnell
Copeia 1:141-152
A Status Review of the Foothill Yellow-legged Frog in California
PDF, 21.7MB
California Department of Fish and Wildlife
California Department of Fish and Wildlife
September 2019
Abstracts from the 2006 Annual Meetings of the Society for Northwestern Vertebrate Biology and the Washington Chapter of the Wildlife Society Held Jointly at Evergreen State College, Washington, March 27-April 1, 2006
PDF, 310KB

Northwestern Naturalist 87(2):153-194
Analysis of long-term river regulation effects on genetic connectivity of foothill yellow-legged frogs (Rana boylii) in the Alameda Creek watershed
PDF, 980KB
Peek, R.
Prepared by Stillwater Sciences, Berkeley, CA for SFPUC, San Francisco, CA.
Conservation Assessment for the Foothill Yellow-legged Frog in Oregon
PDF, 2.2MB
Olson, D. H. and R. J. Davis
Report for U.S.D.A. Forest Service Region 6 and U.S.D.I. Bureau of Land Management
Ecological Aspects of Foothill Yellow-legged Frogs (Rana boylii) in the Diablo Mountain Range on Upper Coyote Creek in Santa Clara County, CA
PDF, 1.5MB
Gonsolin Jr., T. E.
A Thesis Presented to San Jose State University
August 2010
Flow regulation associated with decreased genetic health of a river-breeding frog species
PDF, 2.3MB
Peek, R. A., S. M. O'Rourke, and M. R. Miller

Foothill yellow-legged frog conservation assessment in California
PDF, 3.4MB
Hayes, M. P., C. A. Wheeler,. A. J. Lind, G. A. Green, and D. C. Macfarlane
U.S. Department of Agriculture, Forest Service, General Technical Report, PSW-GTR-248
Habitat correlates of distribution of the California Red-legged frog (Rana aurora draytonii) and the Foothill Yellow-legged frog (Rana boylii): Implications for management
PDF, 2.1MB
Hayes, M. P. and M. R. Jennings
nagement of Amphibians, Reptiles, and Small Mammals in North America, pg. 144-158
July 1988
Habitat Models for the Foothill Yellow-legged Frog (Rana boylii) in the Sierra Nevada of California
PDF, 3.7MB
Yarnell, S. M. C. A. Bondi, A. J. Lind, and R. A. Peek
Center for Watershed Sciences Technical Report, University of California, Davis. 75 pp
Landscape Genetics of Foothill Yellow-Legged Frogs (Rana boylii) in regulated and unregulated rivers: Assessing connectivity and genetic fragmentation
Peek, R.
Master's Thesis for University of California, San Francisco
Population-level variation in vocalizations of Rana boylii, the foothill yellow-legged frog
PDF, 3.3MB
Silver, C. S.
Master's Thesis for California State University, Chico
Pulsed flow effects on the Foothill Yellow- Legged Frog (Rana boylii): Integration of empirical, experimental, and hydrodynamic modeling approaches.
PDF, 6.2MB
Kupferberg, S. Lind, A., Mount, J., and Yarnell, S.
California Energy Commission, PIER. CEC-500-2009-002
Pulsed Flow Effects on the Foothill Yellow-Legged Frog (Rana boylii): Population Modeling
PDF, 1.6MB
Kupferberg, S.J., Lind, A.J., and Palen, W.J.
Final Report. California Energy Commission, PIER. Publication number 500‐09‐02a
Reintroduction of a Declining Amphibian: Determining an Ecologically Feasible Approach for the Foothill Yellow-legged Frog (Rana boylii) Through Analysis of Decline Factors, Genetic Structure, and Habitat Associations
PDF, 1.6MB
Lind, A. J.
Dissertation, University of California, Davis
REPLY COMMENTS of Placer County Water Agency on the California Department of Fish and Game’s Federal Power Act § 10(j) Recommendations
PDF, 9.9MB
Placer County Water Agency

Spatial Ecology of an Inland Population of the Foothill Yellow-Legged Frog (Rana boylii) in Tehama County, California
PDF, 1.5MB
Bourque, R. M.
A Thesis presented to Humboldt State University
December 2008
Supplementary Data Catenazzi and Kupferberg 2013
PDF, 301KB
Catenazzi, A. and S. J. Kupferberg

The Grand Dame of the North Fork Feather River: Insights into Longevity from Photographic Identification of Individual Foothill-yellow Legged Frogs (Rana boylii) Using Chin Mottling Patterns
PDF, 1.9MB
Marlow, K. R., K. D. Wiseman, C. Wheeler, J. E. Drennan, and R. E. Jackman
The Importance of Water Temperature and Algal Assemblage for Frog Conservation in Northern California Rivers with Hydroelectric Projects
Kupferberg, S., A. Catenazzi, and M. Power
Energy Research and Development Division Final Project Report
April 2011

Questions and Answers

Submit a question on this subject and we'll provide an answer. coastaltraining@elkhornslough.org