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Many of the causes of amphibian declines are well understood, and appear to affect other groups of organisms as well as amphibians. These causes include habitat modification and fragmentation, introduced predators or competitors, introduced species, pollution, pesticide use, or over-harvesting. However, many amphibian declines or extinctions ...
A 2019 Science review assessed that chytridiomycosis was a factor in the decline of at least 501 amphibian species during the past 50 years, of which 90 species were confirmed or presumed to have gone extinct in the wild and another 124 had declined in numbers by more than 90%. [37]
However, many of the causes of amphibian declines are still poorly understood, and the topic is currently a subject of ongoing research. Modeling results found that the current extinction rate of amphibians could be 211 times greater than the background extinction rate. This estimate even goes up to 25,000–45,000 times if endangered species ...
Most amphibian species are also threatened by native habitat loss, [41] and some species are now only breeding in modified habitat. [42] Endemic organisms with limited ranges are most affected by habitat destruction, mainly because these organisms are not found anywhere else in the world, and thus have less chance of recovering.
The ancestors of frogs crawled out of water around 400 million years ago. 250 million years ago, frogs were the earliest representation of what would become the modern amphibian orders. Amphibians have been on Earth for longer than mammals or birds; they were even here before dinosaurs. Recently, it has been reported that the extinction rate of ...
However, the zoospores are capable of chemotaxis, and can move towards a variety of molecules that are present on the amphibian surface, such as sugars, proteins and amino acids. [9] B. dendrobatidis also contains a variety of proteolytic enzymes and esterases that help it digest amphibian cells and use amphibian skin as a nutrient source. [10]
When natural habitats are destroyed or natural resources are depleted, the environment is degraded; direct environmental degradation, such as deforestation, which is readily visible; this can be caused by more indirect process, such as the build up of plastic pollution over time or the buildup of greenhouse gases that causes tipping points in ...
Amphibian Ark is an organization that was formed to implement the ex-situ conservation recommendations of this plan, and they have been working with zoos and aquaria around the world, encouraging them to create assurance colonies of threatened amphibians. [178] One such project is the Panama Amphibian Rescue and Conservation Project that built ...