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Spring Amphibian Migration Begins, Be Careful While Driving!

Warmer evenings have arrived and with them the biggest logistical operation undertaken by frogs and other amphibians. During their spring migration, these tiny fighters leave their wintering grounds and head out to find water.

Why?

Amphibians need water to reproduce because they lay eggs in it, which then hatch into tadpoles or larvae. This includes species that are otherwise land-based for most of the year.

From where to where?

Typical wintering sites include various holes in the ground or nooks and crannies in piles of branches, logs, sod, grass, and other materials that are more hospitable. From there, they travel to their breeding grounds. These can be nearby ponds, pools, wetlands, or even artificial ponds in city parks. Such destinations can be dozens, hundreds, or even thousands of meters away.

When?

Migration begins when nights get warmer (sometimes just a few degrees above zero) and wetter. However, the exact timing of a spring migration varies from year to year depending on the weather. It also depends on altitude and, of course, the particular animal species. However, the period of mass spring migration lasts from the end of February to mid-May.

Risks

Amphibian pathways remain the same or very similar for generations, even when they are obstructed by roads. In addition, frogs move at night during the spring migration (natural protection from predators) and are easily intoxicated by close physical contact (sometimes, for example, a smaller male travels on the back of a female, called amplexus). Their movement is usually extremely slow.

When migrating frogs collide with an inattentive or careless driver on the road, carnage ensues. The result is hundreds of dead amphibians and decimated local populations.

Please keep your eyes peeled when driving in the dark through the countryside in the next few weeks. In some areas, particularly protected areas, conservationists are installing temporary 30cm high fences to prevent frogs from entering the roadway, but this is only on a fraction of the roads. Elsewhere, only divers’ caution will help.

Common toads suffer the most, and according to statistics, most of them die on the roads. Common toads can cover distances of three kilometers or more, move in a matter of days, at a very slow pace, and freeze in a warning posture when faced with the headlights of oncoming cars. This often results in their death.

The second most endangered species during the spring migration is the Common frog, which emerges from its wintering grounds in early spring, sometimes as early as the end of February.