Endangered frogs experience population explosion in Switzerland
Endangered frogs are experiencing a population explosion in Switzerland. Targeted conservation programmes are showing remarkable results.
The populations of all endangered frog species in Switzerland “exploded” when scientists launched a simple pond-building initiative.
Among the main beneficiaries were tree frogs, whose numbers have quadrupled since 1999, as have the number of areas in which they occur.
422 ponds as a rescue programme in Aargau
Although the Swiss canton of Aargau has strict protection laws for a number of frog, newt and toad species, scientists wanted to find out whether habitat restoration could provide new impetus for continually declining populations.
In 1999, a 20-year programme was launched in collaboration with the Aargau government, non-profit organisations, volunteers and landowners to construct 422 ponds across five regions of Aargau.
Most frogs need small pools that form naturally in the bends of slow-flowing watercourses.
Recovery in more than half of species
Of the eight endangered species, 52% were able to increase their regional populations and 32% to stabilise them.
"Habitat loss is one of the main problems, and by addressing this issue alone we were able to see the difference and initiate the recovery of these species," lead study author Dr Helen Moor told BBC News. "The most important message is that it is worth doing something, even when it feels overwhelming."
One of the species that has recovered particularly strongly is the tree frog. This tiny frog can travel several kilometres in search of a suitable habitat for egg-laying.
New ponds as the key to species conservation
Frogs need new ponds to migrate to, as predator species eventually enter existing ponds to feed on their tadpoles. The few pools that existed before the project were often occupied by these predators.
The scientists believe that this simple measure of pond construction can contribute to the restoration of amphibian populations in human-dominated landscapes. The example shows that conservation without culling is effective – a principle that the Geneva Model has successfully demonstrated since 1974.
