Amphibians:

Survival between water and water bodies

Amphibians move between water and land. The animals need wet biotopes and still waters.

(Bild: Armin Furlan)

The migration season for frogs, toads and co. has begun in the Ländle. Many of the native species are endangered. Spawning waters and animal observations can be reported as part of a monitoring project.

They lead a rather "reclusive" lifestyle, which is why we humans don't see them very often. They live in the damp, cool shade of forests, clear streams and various bodies of water. Their existence is a balancing act between water and land. During the first frost-free nights, many of them leave their winter hiding places to return to the waters where they hatched.

A total of 14 different amphibian species can be found in Vorarlberg. The grass frog and common toad in particular migrate early from February/March and often over long distances to reach their destination. "A total of 53 spawning waters were reported throughout Vorarlberg as part of the amphibian monitoring program. There are certainly more, but they have not yet been recorded in the database," explains Elisabeth Ritter from inatura Dornbirn's specialist advisory service.

Inatura is responsible for the project together with the state's Department for Environmental and Climate Protection. "The aim is to use the data obtained to create a nationwide inventory that includes information on the spawning waters and the species that occur in them," explains Ritter. This will then serve as the basis for targeted conservation measures in the future. The experts are reliant on the help of volunteers for the survey. "Anyone can help with the research by reporting spawning waters or amphibian observations," explains Ritter.

Together with reptiles, amphibians are among the most endangered groups in the animal kingdom. Frogs, toads and newts are heavily dependent on the availability of suitable spawning grounds. Wetlands, ponds and structurally rich landscapes are essential for their reproduction and development. Unfortunately, many of these habitats are threatened by human intervention. "Drainage, land sealing and the regulation of watercourses - these are just a few examples of human land use that are causing the animals to lose their habitats," the expert points out.

Drying out is dangerous
According to Ritter, there are also the effects of climate change, introduced diseases (such as the chytrid fungus), displacement by non-native species such as the lake frog and the use of biocides and fertilizers, which make it difficult for amphibians to survive. Road traffic also claims a considerable number of victims, with migratory species being particularly affected. Extreme heat and long periods of drought also have a negative impact: When habitats and spawning waters dry out, the animals suffer massively. This is because the skin of amphibians has no scales and is permeable to water, which is why they are dependent on sufficient moisture.

Amphibian-friendly gardens

You can also help protect amphibians in your own garden:

- Allow flowering areas for a diverse insect world as a food source

- Avoid the use of pesticides and chemical fertilizers

- Hedges of native shrub species provide important retreats and migration corridors

- Provide piles of branches and dead wood as hiding places

- Eliminate hazards in the garden: cover shafts and drains with fly nets or close-meshed grids, secure basement windows and wells, install amphibian ladders on (basement) stairs, swimming pools, etc.

- Fish-free garden pond

Important note: Amphibians must never be caught!

Their existence is generally closely linked to the element of water and also begins there. After a few days or weeks, tadpoles hatch from the spawn, which is often deposited near the shore or on water plants. These initially consist only of a head and tail. They also have gills, which means that they can only live in water. By the time they reach adulthood, however, they undergo an almost fantastic metamorphosis: legs grow, gills give way to lungs, the tail recedes and finally they venture onto land. Almost all amphibian species develop in this way. One of the few exceptions is the Alpine salamander, which - adapted to its extreme habitat - gives birth to its offspring as a live birth.

Migration corridors necessary
However, adult amphibians also remain dependent on moist habitats. "A prerequisite for the long-term conservation of the amphibian fauna is therefore the consistent protection of these areas and their connectivity," emphasizes Ritter. It must be possible for the animals to migrate safely between their aquatic and terrestrial habitats. The revitalization of watercourses could create habitats and urgently needed migration corridors. "Precisely because they need this connectivity, they are even more susceptible to environmental changes than other animal groups," says the biologist.

Amphibians are therefore not only an important part of the ecosystem, but also indicators of how our natural habitats are doing. And things are not looking very good in this respect.