About Amphibia

1. Landscape Fragmentation and Loss of Natural Habitat

– Roads and traffic significantly increase mortality during the spring and autumn migrations of amphibians. This is primarily due to the insufficient number of migration underpasses beneath roads. During these seasonal movements between overwintering sites and breeding water bodies, amphibians suffer heavy population losses. Roads are also often full of invertebrates after rainfall—particularly earthworms and slugs, which amphibians feed on—so while foraging, they frequently fall victim to passing vehicles.

​

– Urban expansion and intensive agriculture lead to the destruction of natural habitats. In practice, this includes the drainage of wetlands for human development, despite wetlands being vital ecosystems for many frog and salamander species. Another major threat is the afforestation of European landscapes with fast-growing tree species (such as Norway spruce), which acidify the soil and thus create unsuitable conditions for amphibians with sensitive skin.

​

2. Decline and Pollution of Water Bodies

– Loss of suitable breeding habitats, such as ponds, wetlands, and temporary pools. A common trend is the stocking of fish into water bodies, which increases predation on both larvae and adult amphibians. Another issue is the reinforcement and backfilling of forest roads, which eliminates deep puddles created by forestry machinery. These puddles often serve as valuable breeding sites for species such as the yellow-bellied toad.

​

– Water pollution, caused by pesticides, industrial waste, or eutrophication (excessive nutrient loading, e.g., from fertilizers), leads to habitat degradation. Such pollution forces amphibians to migrate to other locations or directly causes mortality due to toxic exposure.

 

3. Disappearing Understory and Unsustainable Forest Management

– Removal of understory vegetation results in the loss of natural shelter and overwintering sites. The lack of cover increases the risk of desiccation and predation.

​

– Mechanized forestry operations—such as logging with harvesters or the movement of tractors off designated forest roads—destroy overwintering sites and pollute habitats with oil, mud, and plant debris, especially wood. Another major problem is soil compaction, which prevents amphibians from burrowing and creating shelters.

​

4. Introduced Diseases and Non-native Species

– Chytridiomycosis is a deadly fungal disease introduced by exotic amphibians, likely from Southeast Asia. It is devastating populations of European amphibians, particularly the fire salamander.

​

– Invasive species, such as the American bullfrog (Lithobates catesbeianus), compete with native amphibians and disrupt local ecosystems.

​

5. Inappropriate Handling and Captive Keeping

– Keeping wild amphibians as pets leads to the isolation of individuals from their natural populations. Inadequate conditions in captivity often result in their death.

​

– Releasing captive individuals into the wild increases the risk of disease transmission and especially genetic pollution. This is particularly concerning in fire salamanders, where interbreeding between subspecies from different parts of Europe leads to the loss of distinct local genetic lineages.

​