Why We Care about the Victims
One reason so many amphibian biologists were eager to join the task force was simply because they were worried they might be losing their objects of study. But they were even more concerned for other reasons that everyone can appreciate. The first is the ethical consideration that amphibians have the right to exist. If people are responsible for amphibian disappearances, then people have a moral obligation to prevent them. Most religious traditions assign value to all living organisms. Even Judeo-Christianity, which espouses that humans are a special creation of God and are given dominion over the rest of the living organisms on earth, teaches that this relationship should be a stewardship, not a slaughter.
Second, amphibians are fascinating organisms that interact in complex ways with each other and their environments. Consider the life history of the Central American strawberry poison frog Dendrobates pumilio. At the beginning of their reproductive cycle, males call for females from perches on the tropical forest floor. After mating, the female lays her eggs in the forest’s leaf litter. The father then revisits the eggs and keeps them moist with bladder water. When the eggs hatch into tadpoles, the mother carries them on her back and deposits each one into a tiny pool of water, often dew that collects at the base of bromeliad leaves. Because there is seldom enough food for even a single tadpole in these pools, the mother revisits each one every few days and lays an unfertilized egg for her offspring to eat. As the frogs mature, they synthesize poison toxins in their brightly colored skin from compounds found in the native arthropods on which they feed. If such frog species disappear, we lose valuable information about life on earth.
Third, amphibians may provide direct benefit to humans. One example is the gastric brooding frog, Rheobatrachus silus, of Queensland, Australia. After the female’s eggs are fertilized, she swallows them and uses her stomach as a brood pouch, somehow switching off her digestive enzymes during the incubation period. Knowledge of such an enzyme-suppression mechanism might have proven helpful
to people suffering from gastric ulcers. Unfortunately, while these and other biological aspects of R. silus were being investigated, the species disappeared from its natural environment, and all specimens in the laboratory died. For a rough idea of what we’d be missing if many such species disappeared, consider some benefits that have already been realized, including a pain killer recently derived from poison-frog toxins and a nonirritating vaginal cream made from frog skin that prevents pregnancy and protects against sexually transmitted diseases (see “All Natural AIDS Protection?” TR August/September 1996).
The fourth and primary reason that the task force was established is that amphibians are important indicators of general environmental health. Because most amphibians have a biphasic life cycle-they spend their early stages in water and their adult life on land-and have extremely thin, permeable skin, any changes in either aquatic or terrestrial environments may significantly affect these creatures. Thus, amphibians may provide early warnings of deteriorating environments that appear unaltered to human perception.