Conservation: Explosion in frog numbers after mass pond digging- PublishedSwitzerland has reversed the decline of more than half of endangered frogs, toads and newts in one region, research finds.After conservationists dug hundreds of new ponds in the canton of Aargau, amphibian numbers significantly increased.In 1999 Aargau decided that a mass conservation effort was needed to combat the loss of amphibians."Habitat loss is one of the main problems, and just by addressing that we could see the difference it made, and begin the recovery of these species," she says.It could only be found at 16 sites in Reusstal in 1999 but by 2019 the species was living in 77 places."