Conservation scientists want $404 million to save disappearing amphibians
Rhett A. Butler, mongabay.com
September 20, 2005
Yesterday conservation scientists proposed a $404 million effort to preserve declining global amphibian populations. The strategy would call for funding from governments, private institutions and individual donors to finance long-term research, protect critical habitats, reduce the trade in amphibians for food and pets, and establish captive breeding programs.
Earlier this year, the Global Amphibian Assessment, a survey of the planet’s amphibian species, found that nearly a third (32%) of the world’s 5743 known amphibian species are threatened and 129 species have gone extinct since 1980. Scientists believe there may be around 10,000 amphibian species on the planet.
No one is certain why amphibian populations are declining around the world. One leading theory links global climate change to the emergence of the deadly chytrid fungal disease. This fungus, which kills frogs by damaging the keratin layer of their skin, has decimated frogs worldwide.
Among the species to disappear is Costa Rica’s Golden toad (Bufo periglenes) and the Gastric Brooding Frog (Rheobatrachus silus) of Queensland, Australia. Habitat loss and pollution are also considered major threats to global amphibian populations.
Strawberry poison-dart frog in bromeliad
Dendrobates pumilio, the strawberry poison dart frog, is common in the Atlantic lowland tropical forests of Central America especially Costa Rica. Dendrobates pumilio is well known for its parental care. The female typically lays 3 to 5 eggs in a jelly-like mass that keeps them moist and both parents visit the eggs to ensure their survival. Once the eggs are ready to hatch, one of the parenst steps into the jelly-like mass, freeing the tadpoles. The tadpoles respond to the movement and climb onto the parent’s back, where they adhere to a mucus secretion. The parent then carries the tadpoles to up the canopy where they are often deposited in water caught in the upturned leaves of bromeliads. Each tapdole is deposited in a separate pool to increase the likelihood that some offspring will survive predators.
More Frog and toad photos
Ecologists fear that the global decline of amphibians may have broader implications for the world’s environment. Because amphibians have highly permeable skin and spend a portion of their life in water and on land, they are sensitive to environmental change and can act as the proverbial “canary in a coal mine,” indicating the relative health of an ecosystem. As they die, scientists are left wondering what plant or animal group is next.
The disappearance of amphibians is troubling on other grounds as well. Many frogs and toads secrete toxic alkaloids to protect themselves from predators. These alkaloids have been found to have medical applications as pain killers. Thus the loss of each amphibian species eliminates the possibility of finding compounds with potential curative properties.
Time is running out for the world’s amphibians; scientists are trying to act before it is too late. The longer the delay, the higher the cost of inaction.
Study discovers why poison dart frogs are toxic: Poison poison dart frogs are small, colorful frogs found in the tropical forests of Central and South America. The brilliant coloration of these amphibians warns predators of their extraordinary toxicity — the golden poison frog (Phyllobates terribilis) of Colombia is said to be lethal if held in one’s hand. Scientists have long speculated on the origin of their toxins, but now, a new study published in the current issue of The Proceedings of the National Academy of Sciences reports that poison dart frogs, as well as the Mantella poison frogs of Madagascar, derive their toxicity from the ants they eat. Specifically, both groups are frogs are capable of storing ants’ toxic alkaloid molecules in their glands without being harmed. Ants either synthesize these alkaloids themselves or acquire them from the plants on which they feed.
16% of frogs species in Sri Lanka may be gone, new survey finds: In a study published Thursday in Raffles Bulletin of Zoology, researchers confirmed the discovery of 35 new frog species in Sri Lanka over the past decade brining the number of frog species in the island country to 105. However, the survey found that 17 of these species have disappeared and at least another 11 face imminent extinction unless their habitat is protected.
Toad on brink of extinction, scientists race to study amphibian for bioactive compounds: Under the bright florescent lights of a New York reptile house, a colorful exotic toad makes its final stand. Once gathering by the thousands in the waterfalls of the Kihansi Gorge of Tanzania, the population of the Kihansi Spray Toad now stands at less than 200 individuals. The hasty construction of a desperately needed dam has relegated this species to the fringe of existence. Since medically valuable compounds have been derived from amphibian secretions in the past, researchers at Cornell University are working to determine if any bioactive compounds are present in the skins of Kihansi spray toads before it is too late.
Overstaying Their Welcome: Cane Toads in Australia: Cane toads, a particularly destructive invasive species, are making headlines in Australia after an Australian Minister of Parliament from the Northern Territory sparked outrage from animal welfare groups when he urged people on Australian radio to club toads to death with golf clubs and cricket bats.
This article used quotes and other information from other articles on mongabay.com.