Frogs are amphibians, which comes from the Greek language and means “both lives.” Most frogs are born in water as tadpoles and gradually change into frogs although some frogs, known as direct developers, are born as full frogs. This allows them to be born and live far away from water, such as on mountaintops.
A frog mainly lives on insects and small animals like earthworms, minnows, and spiders.
There are approximately 4740 species of frogs around the entire world. There are about 90 species of frogs in the United States. Unfortunately about 120 amphibian species, including frogs, toads and salamanders, have disappeared since 1980. Historically one species of amphibian disappears every 250 years.
Frogs can be found on every continent in the world except Antarctica. However, the highest concentration of frogs is found in warmer tropical climes.
Frogs are known as indicator species and can give scientists valuable insight into how an ecosystem is functioning. Because they are predators and prey many animals are affected by them so frogs are a good indication of the health of the ecosystem.
One of the most pressing threats to frogs today is the chytrid fungus, a deadly skin fungus that has moved across the globe causing amphibian declines in Australia, South America, North America, Central America, New Zealand, Europe, and Africa killing frogs by the millions. The chytrid fungus is responsible for over 100 frog and other amphibian species extinctions since the 1970’s. Chytrid fungus has been detected on at least 285 species of amphibians (including frogs) from 36 countries.
Climate change is also having an impact on frogs that live on mountain tops. They are being hit hard since they are dependant on moist leaf litter found in cloud forests as a suitable place to lay their eggs. As temperatures increase further up mountain sides, clouds are being pushed further away and leaves are drying out leaving less suitable habitat for frogs to lay their eggs. As frogs migrate further up the mountain they are faced with the inevitable problem that once they reach the top, unlike birds, they can go no further.
Frogs are also facing many threats from many different environmental factors: pollution, infectious diseases, habitat loss, invasive species, climate change, and over-harvesting for the pet and food trades are all contributing to the rapid rise of frog extinctions since 1980.
Chytrid fungus has been recognized as one of the largest threats to amphibian populations around the world. In 2009 a group of organizations came together to respond to the crisis. Defenders of Wildlife (Washington DC), Africam Safari Park (Mexico), Cheyenne Mountain Zoo (Colorado), the Smithsonian National Zoological Park (Washington DC), the Smithsonian Tropical Research Institute (Panama), Zoo New England (Massachusetts) and Houston Zoo (Texas) have launched the Panama Amphibian Rescue and Conservation Project.
There are yet undiscovered species of frogs in the world. A new species of flying frog was discovered in the Himalayan Mountains in 2008.
- Endangered Species Act: Under the Endangered Species Act (ESA), five species of frogs are currently listed as endangered and three as threatened.
- IUCN Red List: Nearly one-third (32 %) of the world’s amphibian species are known to be threatened or extinct. At least 42 % of all species are declining in population, indicating that the number of threatened species can be expected to rise in the future