Researchers analysed the diet of otters; it includes rare bullhead
Photo: Fotolia
Researchers analysed the diet of otters living in Drawa National Park. It turned out that it includes bullhead - a rare species, subject to partial protection. If otters manage to hunt it down, it means that its population in the Drawa and its tributaries is quite large - said conservation specialist.
Otter is a territorial animal. In exposed places, for example under bridges, on rocks, logs and mounds of earth it leaves gelatinous secretion, with which it marks its territory. Next to it you can find characteristic greenish droppings.
In such places by lakes and rivers, from January 2012 to August 2013 the Park employees collected otter droppings. In the following months, a thorough analysis of the collected material was carried out. In total, the experts examined the faeces collected from 28 locations and 130 animals.
"Research has confirmed that the main food of otters, also in our Park, are fish. They are approx. 70 percent of the whole diet of these animals. Dominant among them are perch and carp fish - roach, rudd, bream, white bream, bleak, minnow. Bullhead and pike are less common" - told PAP conservation specialist Joanna Sanocka-Bielatko.
Noteworthy is the presence of bullhead on otters’ menu, as it is a rare species under partial protection, included in Annex II of the EU Habitats Directive. The fact that otters hunt bullhead, testifies to the fact that the population of this fish in the Drawa and its tributaries is quite large.
Studies have shown that secondary food of otters living in the Park are aquatic invertebrates and amphibians. The latter are eaten most often in the spring. The share of birds and mammals in the diet of otters is marginal.
"The study also demonstrated the diet variability between otters in the eastern and western side of the Park. Animals inhabiting the eastern arm eat more perch and more often prey on birds than animals living near the Drawa. The diet of the Drawa otters is more varied, it includes more beetles, crayfish, amphibians, bullhead and carp fish"- said Sanocka-Bielatko.
European Otter (Lutra lutra) appears in the DNP logo. In the park, this animal populates all aquatic environments. The number of otters in the Park is estimated at 20 animals. In Poland, the otter is covered by partial protection.
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