Helminths of white stork Ciconia ciconia in north-eastern Poland.

The aim of the study was to determine the structure of helminth communities of White Stork in north-eastern Poland in the years 2015-2018. The study material comprised 61 White Storks Ciconia ciconia from within the borders of Biebrza National Park. Seven parasite taxa were detected in the storks. The cestode Dictymetra riccii, the nematode Dispharynx cf. nasuta, and acanthocephalans are new parasites for storks in Poland. Prevalence of helminths was 32.8%, with a mean intensity of 12.2, in a range from 1 to 60 and with mean abundance of 3.8. The biodiversity of the component community expressed by Simpson's diversity index was 0.639, and dominance expressed by the Berger-Parker index was 0.485. The dominant species in the component community was the cestode Dictymetra discoidea. The average biodiversity of infracommunities, expressed by Brillouin's diversity index, was 0.07 ± 0.13. The greatest species richness of helminths in storks was recorded in July (five species). The greatest intensity of infection was noted in the case of infection with Tylodelphys excavata in June. The prevalence of the cestode Dictymetra discoidea in adult storks (35.5%) was significantly higher than in juvenile storks (4.17%) (chi2 = 7.78, p = 0.005).