Texas Amphibian Watch

Introduction

The word "amphibian" comes from a combination of two Greek words which literally means "two lives," and refers to the distinct two-stage life-history pattern characteristic of most members of this group. Most amphibian eggs hatch into free-swimming, gill-breathing larvae. In most species these strictly aquatic larvae undergo a radical alteration of their body structure (metamorphosis), including the development of lungs, in order to live on land.

Texas has a diverse set of species, the greatest abundance and diversity in the relatively wet habitats of the eastern third of the state. ... Some frogs, including the "true frogs" (such as Bullfrogs and Leopard Frogs), are basically tied to permanent wetlands, whereas others, like the true toads can use wetlands which are more seasonal in nature.

Amphibians, because of their two-stage life cycle and water-permeable eggs and skin, are sensitive to climatic factors (such as drought), habitat changes, and to a wide variety of environmental pollutants like pesticides, petroleum hydrocarbons, and heavy metals. The introduction of non-native species such as fish in some habitats and, ironically, the Bullfrog in others has had profound negative effects on many other species of frogs and toads.

Frogs like this bullfrog often fill the nighttime with their calls and songs.

Amphibians, as a consequence of their unique characteristics, can serve as excellent bio-indicators of the environmental health of a number of terrestrial and freshwater aquatic ecosystems worldwide. Unfortunately, they are sending us the same message as many other species of animals and plants: ecosystems worldwide are changing faster than many organisms can adapt, and the consequent extinction rate is significantly higher than the normal background levels throughout the long history of life on earth. Add in the alarming rate of malformations in some amphibian populations, and it seems amphibians may have much to tell us about the quality of our environments.