Ponds, as natural or semi-natural small freshwater eco-systems, have great biological wealth. A significant number of now rare and endangered species – insects, amphibians, reptiles, and so on – is tied to island ponds and the marsh vegetation that surrounds them.
Ponds are particularly important for dragonflies and damselflies, terrapins, various wetland snakes, a series of frog species, while birds use them as resting and watering places.
Ponds in shallow karst sinkhole depressions have great importance because they were the main source of water in the past and, consequently, were greatly influenced by human activity. In the arid conditions of a great part of the island area, ponds are an important factor, particularly in watering the livestock. However, the shallow standing water are endangered because of the natural process of eutrophication, excessive growth. A great number of wetland plants are distinguished by a great organic production through the whole year. The organic mass created by those species in the vegetating season does not completely decompose but is deposited on the shoreline and bottom of the pond, and that raises the bottom – that is, the water becomes shallower. By their organic production, wetland plants greatly influence the eutrophication process because, after a while, they retreat before species from drier habitats and the pond disappears.
Kornati are in the karst zone where the geological foundation is generally not favourable for the existence of surface waters. Such habitats – that is, ponds – are very rare and because of their surface area extremely sensitive and therefore it's important to maintain their size and ecological variability. For the plant species in such a habitat to survive depth of water during the whole year has great importance, that is, the water level is one of important factors that influence the survival of those species and their communities.
Pond is a natural depression where precipitation collects. Even today, ponds serve as watering holes for sheep and therefore their existence is necessary for the survival of sheep farming – the traditional life of the islanders. The pond is an excellent example of the blend where the natural, cultural and historical heritage of this area unite. Unfortunately, because extensive livestock farming is dying out on Kornati – only the older population remains on the islands – the traditional pond management is not possible anymore.
Giant Peacock Moth (Saturnia pyri)
Another giant on Kornati. This moth with fat, soft, and hairy body has the wingspan of 15 cm and is the largest moth in Europe. Most often it can be seen at night, during April and May. On each wing it has a multicoloured circle, reminiscent of an eye. The "eyes" are actually an excellent defense survival mechanism. While the moth is resting, it is comparatively inconspicuous. But when disturbed, it suddenly opens the wings and shows the "eyes", confusing the predators. The females secrete pheromones (sex hormones) in order to attract the males. Only a couple of pheromone molecules are enough for the male to come over from far away. Their green caterpillars with hairy blue warts are particularly attractive.