Sexual maturity is the point in an individual’s life history that demarcates the preparation for passing on heritable traits from being capable of passing them through sexual reproduction. Earlier age at sexual maturity confers a higher probability of surviving to pass on genetic material; and higher fitness because offspring are born sooner and potentially reproduce sooner. Age at sexual maturity is a trait that profoundly influences the intrinsic growth rate and is integral to predicting the demographic performance of animal populations. Understanding demographic performance allows wildlife managers to assess the relative success of translocations when restoring populations of imperiled species. Observations made of a marked population of California red-legged frogs in the years preceding their translocation to a neighboring county compelled us to reassess published statistics of their age at first reproduction. Informed by our observations, we anticipated that California red-legged frogs are capable of reproducing at an earlier age than previously reported. We translocated 6 egg mass halves over three years and observed several egg masses at the recipient site in the second winter of the project, confirming our observations from the donor site: that at least some California red-legged frogs are capable of sexual reproduction at a younger age than previously reported.

Jeff has held the Managing Ecologist's position at the Mitsui Ranch Preserve in Sonoma County for 14 years. His primary mandate is to use prescribed fire and grazing, along with re-seeding native perennial grasses, to restore rangeland function in and around the preserve on Sonoma Mountain. The Mitsui Ranch Preserve researches native biphasic amphibians in an effort to monitor how their restorations effect amphibian populations.