I heard an interesting newscast the other day – it seems that researchers believe that urban noise might be affecting frog populations because female frogs cannot hear the mating calls over the cacophony of human activities.

In our frog dissection, anatomy and ecology program The Digital Frog 2.5, we address environmental concerns and the effects they have had on frog populations. Since we first published in 1995, new research has identified other possible causes, including urban noise and tiny parasites which have been found to cause damage to devloping limb buds.

It looks like it’s time to update the ecology section in The Digital Frog, part of which you can read here:

Introduction

Many scientists consider frogs important bio-indicators. Frogs have permeable skin and live both on land and in water. As a result, environmental problems quickly affect frogs. Recently, frog populations have declined or disappeared around the world, and deformities and mutations are becoming common. People have found adult frogs with misshapen bodies, extra legs, missing or abnormal organs, and even eyes growing inside mouths!

A Thousand Friends of Frogs

A Thousand Friends of Frogs Project was founded in 1995 to collect data on deformed frogs, and pass the information to research scientists. This project links students, educators, families, and scientists from around the world, and helps to educate people about frogs and their importance to us.

Possible causes

Frog deformities, mutations and declining populations are not likely to result from any single cause; it is much more probable that many factors affect our amphibian friends. Scientists have identified holes in the ozone layer, chemicals, pollution, habitat loss and frog harvesting as possible causes.

Ozone layer

Laboratory tests with ultraviolet light have produced frogs with leg deformities. Scientists speculate that holes in the ozone layer may allow enough ultraviolet light through to affect frogs in the wild.

Chemicals and pollution

Amphibian skin absorbs chemicals from both land and water. Tests show that some chemicals, pesticides, and industrial pollutants cause mutations, abnormal growth, or fatal deformities in frogs.

Industrial and agricultural by-products can harm local frogs. Acid rain and runoff rain can carry these chemicals to places far removed from human habitation.

Habitat loss and frog harvesting

Habitat loss is probably the biggest single factor in declining frog populations. Wetlands are frequently drained, filled in, or otherwise destroyed, depriving frogs of places to live. Commercial harvesting is another pressure. Worldwide, hundreds of thousands of frogs are captured each year and used in laboratories, schools, and restaurants; this causes serious declines in certain species.

Did you know?

We used four frogs in the original Digital Frog and none had deformities. This version required five frogs, and we discovered internal deformities in three of them.

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