Farewell to frogs?
Amphibians have declined drastically in the wild in recent years
Amphibians are the most endangered animals on the planet. In the last 20 years, more amphibian species have declined in numbers than any other group of animals. If we don't work fast, many of these unique and enigmatic creatures could disappear entirely from the wild within our lifetime. If this happens, their importance in medical research, pest control and as indicators of healthy environments will vanish along with them. Could you live in a world without Kermit or Toad of Toad Hall?
Why are they declining?
The decline in amphibians worldwide is due to a number of factors, the most devastating being destruction of their habitats and disease. Their life-cycle and specialised slimy skin mean that they are particularly susceptible to pollution, as well as temperature increases due to climate change. The pet, research and food trades, unsustainable farming practices, and the introduction of invasive or predatory species have also contributed to the recent fall in amphibian numbers.
One of the biggest killers of amphibians is a disease caused by the chytrid fungus, called chytridiomycosis. It is killing off these fascinating creatures at a drastic rate. The future for amphibians hangs in the balance, so research into the prevention and treatment of diseases may be their only hope.
Xenopus and pregnancy testing
The African clawed frog, Xenopus laevis, is thought to be the most likely cause for the worldwide spread of chytridiomycosis. From the 30s to the 50s, these frogs were bred in huge numbers and transported across the world to be used in pregnancy testing. The urine of a pregnant woman was injected under the skin of a female frog, and if the woman was pregnant the chemicals in her urine would cause the frog to lay eggs. However, at the time it was not known that these frogs were carriers of the chytrid fungus, so chytridiomycosis spread to all areas where the clawed frogs went. This species is still widely used in research today, albeit with more precautions in place, but the effects over the years have been devastating to other amphibians.
A positive future
With your support, we believe that there can be a positive future for amphibians. There is a great deal of scientific research and conservation work happening worldwide to help prevent further decline in wild amphibian populations. ZSL is involved in a large number of projects studying and counteracting amphibian diseases and the effects of invasive species; creating sustainable practices for farming and trade; looking into how species move around between habitats and, where possible, reintroducing healthy, captive-bred amphibians back into the wild. ZSL is also a part of and supports the Amphibian Survival Alliance .
In ZSL London Zoo's new amphibian exhibit, you can see inside our amphibian breeding room where ZSL zookeepers and scientists are working with amphibian species that are threatened by chytridiomycosis in the wild and investigating how to counteract the problems they face.
ZSL London Zoo is the only zoo in Europe breeding Mallorcan midwife toads. We maintain small populations of toads that originated from different locations. Their health and genetics are monitored for comparison with infected populations. You may see scientists swabbing the animals' mouths or examining and identifying the adult toads.
EDGE Amphibians programme
ZSL's EDGE of Existence programme conserves the world's most Evolutionarily Distinct and Globally Endangered animals. EDGE Amphibians focuses on protecting the 100 most unique and threatened amphibian species, some of whom give birth through the skin of their backs, live without lungs, or survive without food for ten years. You may have seen an axolotl before, but you've probably never heard of the Chinese giant salamander, the Sagalla caecilian, the olm or the mountain chicken frog.
85% of these animals are not currently receiving any direct conservation attention, so it is imperative that we help them to survive and also work with communities to enable them to care for the extraordinary threatened species that live alongside them.