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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 ...
The main economic factors included commercialization and growth of timber markets (68%), which are driven by national and international demands; urban industrial growth (38%); low domestic costs for land, labor, fuel, and timber (32%); and increases in product prices mainly for cash crops (25%).
A 2013 study estimated that 670–933 amphibian species (11–15%) are both highly vulnerable to climate change while already being on the IUCN Red List of threatened species. A further 698–1,807 (11–29%) amphibian species are not currently threatened, but could become threatened in the future due to their high vulnerability to climate ...
The first major groups of amphibians developed in the Devonian period, around 370 million years ago, from lobe-finned fish which were similar to the modern coelacanth and lungfish. [21] These ancient lobe-finned fish had evolved multi-jointed leg-like fins with digits that enabled them to crawl along the sea bottom.
The quasi-extinction threshold, or sometimes called the quasi-extinction risk is the population size below which a species is considered to be at extreme risk of quasi-extinction. [5] This threshold varies by species and is influenced by several factors, including reproductive rates, habitat requirements, and genetic diversity.
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 ...
It belongs to a lineage believed to have given rise to the three living branches of amphibians - frogs, salamanders and limbless caecilians. Creature named for Kermit the Frog offers clues on ...
Following findings that the parasite Giardia lamblia, which causes giardiasis, was putatively carried by beavers, the term "beaver fever" was coined by the American press in the 1970s. Further research has shown that many animals and birds carry this parasite, and the major source of water contamination is by humans.