AN EFFECTIVE TECHNIQUE FOR THE TRANSLOCATION FOR CALIFORNIA RED-LEGGED FROG EGG MASSES.

Jeff A Alvarez; The Wildlife Project; jeff@thewildlifeproject.com; Mike Paladini, Jeffery T. Wilcox

Effective translocation of wildlife species requires significant understanding of the species’ natural history. In addition, translocation techniques should mimic the conditions that natural population experience. We used a technique to translocate California red-legged frog egg masses that expediently reflected the ovipositioning behavior, hatching conditions, and initial larval development conditions that we witnessed in wild populations of frogs. A floating rearing pen that supported egg masses at the surface and subsequently allowed hatchling larvae to shift to deeper conditions among pond bottom substrate was designed to mimic natural conditions. Egg masses were monitored three times per week until hatching. Post-metamoprhic frogs were monitored weekly and PIT tagged. Over two breeding seasons 2,310 eggs hatched from four translocated egg mass halves and resulted in ≥ 648 post-metamorphic frogs. These frogs showed secondary sexual characteristics in 7 months and were adult size (length and weight) in 15 months. We contend that a critical aspect of the success of this translocation was frequent monitoring during the egg mass placement, and that marking post-metamorphic frogs confirmed success rates.

Ecology and Conservation of Amphibians and Reptiles - II