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Mountain Yellow-legged Frog (Rana muscosa) Fact Sheet: Managed Care

Husbandry and Breeding in Managed Care

Recovery Program at San Diego Zoo Wildlife Alliance

  • Efforts to study the reproduction and natural history of this frog
    • Ultimate goal of preventing its extinction
    • Began in 2006; first successful breeding in 2009
    • Partner program at the Los Angeles Zoo
  • Managed care breeding and reintroduction program
    • Hatch eggs and raise young frogs in managed care
    • Releases into the wild
      • Some frogs released as juveniles are now adults
      • See Distribution
    • Monitor populations (in partnership with US Geological Survey)
      • Census surveys
      • Locate and track using radio telemetry
  • Developing improvements to husbandry and managed care breeding protocols
  • Generally house 40-50 adult breeding pairs (N. Gardner, personal communication 2015)
    • The ideal number may change as scientists learn more about the species' reproduction and genetic diveristy
  • Tadpoles from San Bernardino and San Jacinto mountain ranges brought to SDZWA
    • First collections in 2003 and 2006, respectively

Husbandry and managed care breeding methods at SDZWA

  • Housed in climate controlled aquarium tanks
    • Gravel, water plants, and rocks provided
      • Spaces for frogs to rest, sleep, and hide
    • Simulate season temperatures changes in the wild
      • Provides hibernation cues
    • Simulate natural light cycles
  • Studying the frog's nutritional requirements
  • Studying embryo and tadpole development
    • Use assisted reproduction techniques (e.g., hormone therapies and in vitro fertilization)
    • Provide temperature conditions needed for successful reproduction
      • Use cold to induce hibernation conditions experienced by frogs in their wild, mountainous habitat (Santana 2015)
      • Dramatically improves reproductive success of Rana muscosa in managed care
        • Triggers reproductive/mating behaviors observed in the wild
          • Vocal advertisement, amplexus (copulation), female receptivity, and egg laying
  • Frogs vaccinated for Chytrid (Chytridiomycota) fungua before release into wild (San Diego Zoo Global Press Releases)

Multiple reintroductions in the San Jacinto mountains (N. Calatayud and N. Gardner, personal communications 2015; SDZWA Science Blog)

  • Indian Creek and Hall Canyon releases since 2010
    • Adult frogs now at these sites
  • Fuller Mill Creek, 2015
    • May release: 711 tadpoles
    • August release: 200 late-stage tadpoles and 27 juvenile frogs
  • Dark Canyon, 2016
  • City Creek, 2016
    • September: 150 tadpoles released
    • Population may be locally extirpated (San Diego Zoo Global Press Releases)
    • Plans to reintroduce more "head-started" frogs in 2017

 2016 update (Science Blog)

  • 10th year of San Diego Zoo Wildlife Alliance's Mountain Yellow-legged Frog Recovery Program
  • One of the most productive breeding years to date
    • 17 females in managed care laid clutches of eggs
  • San Bernardino Mountains

Mountain Yellow-legged Frog Tanks

Mountain Yellow-legged frog tadpole tank

Tadpole Tank

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.


Mountain Yellow-legged frog adult tank

Adult Tank

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Page Citations

Santana (2015)

SDZWA Library Links