Amphibians have complex life cycles, dependent on aquatic and terrestrial habitats. Even in the terrestrial habitat, amphibians are heavily dependent on water. They have permeable skin which makes them prone to desiccation, although tolerance of arid conditions varies between species. Amphibians spend some, usually most, of their time on land. The proportion of time spent in the aquatic and terrestrial habitats varies between species and environmental conditions but land habitats are important to all as seasonal habitat and as migratory routes.
Aquatic habitats
Amphibians breed primarily in standing water, especially ponds. Ponds are naturally relatively dynamic environments. Vegetation and water levels can vary substantially over a year as well as more gradually over the long term. Pond-dwelling species tend to be adapted to this changeable environment. Similarly, amphibians are flexible in their ecology.
The two species of Bombina in central Europe have somewhat different habitat requirements. Fire-bellied toad prefers larger ponds, frequently with more and higher vegetation, generally situated in open land. Yellow-bellied toad, on the other hand, prefers water bodies surrounded by forest, usually puddles, ditches or water-filled wheel ruts. For Italian crested newt, ponds can be described as large and deep with submerged vegetation, that hold enough permanent water in the breeding season or trough different years. For all target, species is important that breeding sites are fish-free.
Terrestrial habitats
In the adult stage amphibians shuttle between aquatic and terrestrial habitats on a seasonal basis. Once young amphibians leave the water after the larval stage, most of them spend the juvenile part of their life on land. This period can last for two or three years before they reach sexual maturity and return to the water as breeding adults.
Terrestrial summer habitats of Italian crested newt, fire-bellied and yellow-bellied toad are extensive meadows, with scattered small patches of woodland or scrub, areas of damp meadows, rough grassland and other dense ground vegetation providing excellent insect rich foraging areas. Yellow-bellied toad and Italian crested newt are more of terrestrial species, both leave the ponds rather soon and disperse to their preferred terrestrial habitat – deciduous woodland. They stay close to breeding sites but also actively move around and search for food. Compared to them, the fire-bellied toad is more water-dependent and spends most of the spring and summer in breeding ponds but can also move to feed in other ponds.
In hibernation sites, amphibians survive unfavourable winter conditions in an inactive state. They overwinter in deciduous or mixed forests, where there are enough suitable hiding places, such as under rocks, bark, in-ground holes, between the roots where conditions are favourable enough for survival of the winter. Some species of amphibians can also overwinter in water.
Habitat connections between the populations that allow movement of animals are essential to ensure long-term viability and allow natural re-colonisation of areas if a species becomes extinct in any locality. Terrestrial habitats are therefore important for sustaining individual animals during part of their life cycle, for allowing movement to breeding ponds and for ensuring that animals can move between populations over time.
An important shelter and a food source on migratory routes, amphibians can find in the hedgerows. These narrow, elongated bands of shrubs and trees are overgrown with a more or less rich layer of herbs. Hedgerows represent an important habitat in the landscape that connects different terrestrial and aquatic habitats.
