The world is suffering a crash of amphibian populations, including many species of frogs and toads. Some of the culprits include habitat destruction and fragmentation of wetlands and forests; invasive species, pervasive use of pesticides and herbicides; introduced pathogens, parasitic flukes, and destructive fungi; and perhaps the partial destruction of stratospheric ozone and a consequent rise of exposure to ultraviolet radiation.
The great expansion in human population and economic activity over the past two centuries has come at the expense of the other species with which we share the planet.
In the past half millennium, more than 750 species extinctions have been recorded by the International Union for Conservation of Nature and Natural Resources (IUCN), the keeper of the extinction accounts, including the dodo, the Chinese river dolphin (declared extinct in 2006), and many other birds and marine life.
A vast number of additional species have also been driven to extinction, perhaps by the millions, but these are typically smaller organisms that were not even documented before their disappearance.