BLACK STORK (CICONIA NIGRA) IN THE CENTER OF THE NORTHERN PART OF ZHYTOMYR REGION: NUMBERS, BIOLOGICAL CHARACTERISTICS AND PROTECTION

Abstract

The studies of Black Stork were conducted on the territory of the former Luhyny district that is currently the united territorial community of Zhytomyr region within the period of 2009–2023. The data were obtained by surveying forestry workers as well as conducting our field research. In 2009–2010 the amount of this species constituted 23 pairs and the nesting density was equal to 4.26 pairs/100 km2 of forests, that showed the highest rate among other districts of the region. In 2017–2023, 7 pairs of storks were discovered, many of which were in areas known from our previous research.
C. nigra preferably choose old oaks for nesting (83.33 %) in old-growth groves (60 %). Nesting sites should be located next to the hunting places, obviously small rivers (on average 418 m), but far from populated areas (on average 2.5 km). The size of the nests was from 115 to 151 cm, and the height constituted from 25 to 45 cm.
A tendency towards the decline of the amount of nestlings has been noted that will presumably affect the numbers of Black Storks in the future. Nowadays, the average temperature is increasing and precipitation is decreasing on the territory of Ukraine, which frequently leads to drying of small rivers and swamps. Considering that this species feeds on mainly aquatic organisms, the link between the reproduction of Black Storks and the amount of winter-spring precipitation is clearly traced. If ponds and rivers are not sufficiently filled with water in spring, the birds do not breed or have a small number of nestlings. Pairs that nest close to large rivers that do not dry up, have more offspring. The average number of nestlings in the brood was 2.2 (n=11).
Black Storks flock from migration to the studied territory in the first half of April.
7 nestlings were ringed in 2020–2022. One of them ringed with a white plastic ring with the number U104 in July 2021, was found in September 2021 in the far south of Moldova in Slobozia Mare village, Cahul district. The distance from the nest to the meeting point is approximately 618 km directly to the south. The migration of this bird was in the direction of the Bosphorus.
Great Grey Owls and Common Buzzards can compete with Black Storks for their nests. Lesser Spotted Eagle and Great Grey Owl are not dangerous for C. nigra and can live close to them.
Intensive logging greatly threatens the reduction of suitable nesting places for the species. To preserve Black Storks, it is necessary to create conservation areas around the nests, new territorial nature conservation areas, artificial nest platforms and ponds.