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Interesting animal species
Grebes Podicipedidae
Bodies of water are a nesting site of Grebes: the Great Crested, Black-necked and Podiceps grisegena Red-necked ones. Most of these species may be easily observed on the fish ponds in all the O¶więcim Basin. The first one is the most numerous and the biggest Grebe occurring in Europe. The Red-necked Grebe is a real rarity and there are around twenty pairs nesting here. Grebes are attracted to the ponds by an abundance of small fish, which they hunt diving. The adaptation allowing them to get food in this way is a dagger-like bill; broad lobes on the toes, which work like webs; legs placed far back on the body and a vestigial tail. Grebes often swallow their feathers. In this way compact mass builds up in their stomachs, which protects the stomach walls from getting hurt with sharp fish bones. The birds perform long series of courtship rituals, which are particularly well-developed by the Great Crested Grebe. Courting individuals faithfully imitate their partner's movements; they dance swimming and diving. The species build floating nests, anchoring them amid waterside vegetation. When alarmed, Grebes cover their eggs with parts of plants before leaving the nest. During incubation, eggs change their colour from milky-white to brown. The brown colour comes from decaying plant remains that a grebe nest is made of. Adult individuals swim with their chicks on their back, thus ensuring their greater safety.
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