Arizona Amphibians In Trouble

Arizona’s aquatic species, its amphibians, fish, snails, and dragonflies are in danger.  Frogs and toads are disappearing around the world.  The causes are water diversion, water pollution, disease, and predation by invasive species.  All these are occurring in Arizona.

There is an urgent need for more information about amphibian distribution.  We need local records of the species we see in our neighborhoods, yards, and gardens.  The checklist below is a convenient notebook you can use to record the species you see.  The References list conservation organizations that can use the information.

The photograph shows a Woodhouse’s Toad.  This species lays its eggs in water, and in spring, is  often heard crying in the woods along the Agua Fria River in central Arizona.  One of these palm sized predators often sits beside my back door where light shining through the door’s windows attract moths and other insects.

What’s Harming Amphibians?

Pollutants in streams and lakes produce malformations in aquatic species.  Most visible are the extra limbs, crooked or missing limbs, and facial disfigurements.  These and internal malformations make feeding difficult, and can prevent reproduction.  One-fourth of U. S. amphibian species are affected.  More than half the individuals in some populations are malformed.

Adding to other problems, a fungal disease is attacking and killing amphibians.  The fungus is causing even greater devastation than the white-nose syndrome that is killing bats in the eastern U.S.  The fungal disease attacking amphibians is known as chytridiomycosis.  It is caused by Batrachochytrium dendrobatidis  (Bd).  Recent surveys in Arizona found Bd in several watersheds in the central and southeastern portions of the state.  Ninety-two out of 166 animals tested were infected (Amphibiaweb and http://www.bdmaps.net).

Chytridiomycosis has gotten so bad in some places that the only surviving amphibians are quarantined in isolation tanks.  The Golden Frog, Panama’s national emblem, is now extinct outside of the ‘arcs’ that have been constructed to protect it and other amphibians while researchers hunt for a cure for the disease.

The invasive species that people have accidentally introduced are also harming amphibians.  The Arizona Game and Fish Department (AZGFD) lists the American Bullfrog as one of its ten most unwanted invasive species.  Bullfrogs prey on other frogs and small creatures, and have eliminated species wherever they have become established.  Bullfrogs are not immune to Bd or the effects of human wastes in the water.  Bellows of Bullfrogs in stock watering ponds near my house have announced the arrival of summer for as long as I can remember.  The bullfrog bellows began declining in 2009, and were almost absent in 2011.  It’s wrong, but I can’t help feeling sad that their bellows will soon, perhaps even this year, be heard no more.

Field guides for identifying frogs, toads, and salamanders are available online (Arizona Herpetological Association, Brennan, 2008), and in print (Bishop, 1962, Stebbins, 1966).

Arizona Amphibian References

Amphibian Conservation Alliance:  http://frogs.org/index.asp.

Amphibiaweb:  http://amphibiaweb.org/chytrid/chytridiomycosis.html.

AZGFD (Arizona Game and Fish Department):  http://AZGFD.gov.

Bishop, S.C.  1962.  Handbook of salamanders.  Hafner, New York, NY.  555 p.

Brennan, T.C.  2008.  Online field guide to reptiles and amphibians of Arizona:  http://reptilesofaz.com.

Global Amphibian Assessment:  http://globalamphibians.org/overview.htm.

NBII.  U. S. National Biological Information Infrastructure:  http://nbii.gov.

Partners in Amphibian and Reptile Conservation:  http://parcplace.org.

Stebbins, R.C.  1966.  A field guide to western reptiles and amphibians.  Houghton Mifflin, Boston, MA.  279 p.

U. S. Endangered Species Act.  1973. The act and related laws are discussed at:  http://fws.gov/laws/lawsdigest/ESACT.html.

U. S. Forest Service.  2007.  Regional Forester’s list of sensitive animals:  http://fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev3_021328.pdf.

Arizona Amphibians Checklist

I compiled the checklist from the websites of the National Biological Information Infrastructure (NBII), the Arizona Game and Fish Department, and other sources in the Reference list.

Symbols in the left check box:  S = Sensitive species (U. S. Forest Service), ** = Introduced species, T = Threatened (U. S. Endangered Species Act), E = Endangered (U. S. Endangered Species Act).