In the 2012 President's Budget Request, the National Biological Information Infrastructure (NBII) is terminated. As a result, all resources, databases, tools, and applications within this web site will be removed on January 15, 2012. For more information, please refer to the NBII Program Termination page.
To find out what frogs you are hearing, look up frog calls using the USGS Frog Call Lookup from the USGS Patuxent Wildlife Research Center. There you can learn to identify frog calls and quiz yourself using the frog call quizzes for your area.
Amphibians of the Southwest Region
Arizona Treefrog (Hyla wrightorum) [Photo: Jeff Servoss, USFWS]
Amphibians are a class of vertebrates with over 4,000 species. There are three orders of amphibians: salamanders and newts
, frogs and toads
, and caecilians
. Thought of as cold-blooded, amphibians are ectotherms, meaning they are unable to regulate their own body temperature independently of the temperature of their surroundings. Amphibians are generally small with thin skin permeable to air and water. With few exceptions, amphibians do not actively care for their young. In general, amphibian reproduction strategy consists of egg-laying and external fertilization of a large number of eggs in a moist or fully aquatic environment. Fertilized eggs develop into amphibian larvae that live part of their lives dependent on an aquatic environment requiring gills and specialized feeding habits. Following a pattern of development unique to amphibians, amphibian larvae undergo marked changes and metamorphose into an terrestrial form that lives on land. Typically, this metamorphosis is demonstrated by loss of gills, changes in overall appearance, and changes in diet. The Southwest is home to a variety of ecosystems which provide diverse terrestrial habitats and aquatic habitats, which amphibians depend on for reproduction.
For more information about Amphibians nationwide, visit the NBII Amphibians Web site. There you can find further Web resources on amphibians and the diverse factors affecting amphibian populations globally.