San Diego Natural History Museum--Your Nature Connection[BRCC San Diego Natural History Museum: Herpetology Department]

BRCC
Herpetology

Collections
Research Activities
People
Resources
   - Checklists & Field Guide
   - Rattlesnakes
   - FAQ
   - Articles
   - Recommended Books
   - Exhibits
History
Contact Us

Rattlesnakes!

Local Amphibians Wait for Rain

Life is on hold for many of our local amphibians. Frogs and salamanders rely on the winter rains to complete their life cycle. Without rain, many will delay their emergence from underground retreats. While many amphibians will be active near larger bodies of water, such as lakes and rivers, their foraging area will be greatly diminished due to the dry weather. And because terrestrial salamanders lay their eggs underneath rocks and logs, where the ground stays moist, the dry weather will delay reproduction.

Ensatina escholtzii by Jim Melli and Hyla regilla by BDH

The word amphibian means "double life" and refers to the way many frogs and salamanders rely on water to complete their life cycles. Amphibians hatch from their eggs in a larval form, such as a tadpole. Larvae have gills and other aquatic features which allow them to live underwater. Later, the larvae will metamorphose or change into a terrestrial form. During metamorphosis there is a dramatic change in their appearance. For instance, in frogs, tadpoles will grow legs and absorb their tail and gills.

Tadpoles by Jim Melli and

Amphibians have a number of strategies to avoid predation at either the larval or adult stages. Despite most amphibians dependence on water, some species have evolved ways to avoid living in water altogether. This is because a large number of predators can be found in water. For instance, four of our region's salamanders are completely terrestrial and hatch out as miniatures of the adult form. These fully terrestrial species lack the aquatic, free-swimming, larval stage.