The yellow-bellied toad (Bombina variegata) is a distinctive amphibian found across various parts of Europe. It stands out due to its striking coloration, a clear warning to potential predators.
Identifying a Yellow-Bellied Toad and Its Home
The yellow-bellied toad is characterized by its compact, flattened body, typically measuring between 28 to 56 millimeters in length and weighing 2.3 to 12 grams. Its dorsal side is grey-brown, often featuring faint bright spots and numerous warts with raised swirls. The underside, including its limbs, fingers, and toes, displays a vibrant pattern of bright yellow to orange spots or patches against a grey-blue to black-blue background, often covering more than half of its belly.
This bright coloration serves as a warning signal, indicating its toxicity to predators. When threatened, the toad may arch its back and display its vivid underside, sometimes even secreting toxins from its warty skin. Its pupils are heart-shaped, and it lacks visible eardrums.
The yellow-bellied toad primarily inhabits Central and Eastern Europe. It prefers shallow, temporary bodies of water like ponds, ditches, and muddy areas, which warm quickly and are often free of fish predators. These disturbed habitats, such as flooded wheel ruts or quarry pits, provide suitable breeding grounds for their tadpoles. While historically found along streams and rivers, human development has led them to adapt to these man-made aquatic environments.
Daily Life and Unique Calls
The yellow-bellied toad is nocturnal and aquatic. Its diet primarily consists of small invertebrates, including insects, worms, and slugs. On land, these toads seek shelter under stones, dead wood, or within rock crevices, especially in light forests or marshy meadows.
Breeding occurs from late April to late summer, with males attracting females through vocalizations while floating on the water’s surface. Females lay between 120-170 eggs in small clusters, attaching them to aquatic plants, with each cluster containing about 15 eggs. Tadpoles hatch within a few days and undergo metamorphosis into juvenile toads in about a month, then moving onto land.
The male yellow-bellied toad produces a distinctive, melancholic call, described as a soft “hoo… hoo… hoo” or a bell-like sound. This call, heard at about 80 times per minute, is quieter than some other toad species due to the absence of internal vocal sacs. Males use these calls to attract mates, primarily from afternoon until midnight, though during peak breeding season, calls may be heard throughout the day, especially in clear, windless weather. The species is listed as “Least Concern” by the IUCN, though conservation efforts are underway in some regions, like Germany, to address declining populations.