Distribution and number of Dalmatian Pelican Pelecanus crispus (Aves: Pelecaniformes) in Chelyabinsk Region

The planning of actions for the conservation of a rare species calls for information about the species population size and dynamics. We are concerned with the abundance of Dalmatian Pelican in Chelyabinsk region. The available reliable data on the regional population of the species is scarce. This paper presents the results of the species census which we conducted in Chelyabinsk region in May 2018. For the census, we used the drones DJI Phantom 3 Adv. (with an increased range of up to 6 km) and DJI Mavic Pro Platinum. We counted breeding Pelican pairs on lakes and swamps of the region suitable for nesting. We examined large shallow eutrophic waterbodies overgrown with abundant surface vegetation and reed beds. The waterbodies were located in the flat forest-steppe part of Chelyabinsk region. Information on the places and dates of our research on each waterbody, as well as the results of the counting is provided in the Table. First of all, for the survey we chose the waterbodies previously known as sites of Pelican habitation or similar waterbodies. The results of bird counts in the colonies were more accurate in the evening when Pelicans returned from feeding. When we found different numbers of individuals in the same group at different times, we took the biggest value as the final counting result. The number of birds, due to their large size and bright white color, could be assuredly determined from a distance of 100-150 m. Birds incubating eggs left their nests reluctantly, and even the drone approaching at a distance of 5-10 m drove not more than a third of the birds from their nests. Since the late 1990s to the early 2010s, at different times a few colonies of Pelicans existed on three waterbodies (Kurlady, Salesian, and Donguzly) near the town of Kopeysk. As for other areas of the flat part of Chelyabinsk region, Pelicans had not been recorded breeding there, but many respondents observed flocks of migrating and feeding individuals there from time to time. In 2018, we found nesting Pelicans only on the Donguzly swamp (See Fig. 1) located in the Donguzly Nature Reserve. Their large colony consisted of 132 breeding pairs (nests) and 65 birds (20%) that had no nests. The colony seemed to be at the growth stage and possibly it had absorbed the birds that used to nest on the neighboring ponds. This colony comprised ten groups located on seven separate stretches (See Fig. 2). Each group included from two to 56 nests, and the distance between the remotest nests was 2.7 km. Another known nesting Pelican colony had existed on the neighboring lake Kurlady at least from 2001 to 2014, but at the time of the census it turned out to be abandoned, probably due to the rise of the water level which led to a reduction of the reed bed area. The third known breeding colony once located on lake Selezyan no longer existed, in our opinion due to the fact that many fishermen and camping people disturbed Pelicans there. In 2018, we recorded only 58 non-breeding individuals on the lake, they kept in the backwaters as a flock, flying from one shore to another without staying in any particular place. In 2018, we found a new nesting Pelican site on the swamp Mamynkul in the northeast of the region (See Fig. 1). Even though the swamp is not a reserve area, it is almost never visited by people as it is difficult to access and hunting is prohibited there by the local hunting management authority. On the swamp Mamynkul, we counted 40 individuals, of which 7 couples arranged their nests in a close group on a small island. The absence of last-year nests suggested that the Pelicans had just started breeding there. According to our data, the total number of Dalmatian Pelicans in Chelyabinsk region in 2018 was 427 individuals, with 65% of them breeding. Taking into account these data, the total population of this species in the Asian part of Russia is estimated at 1.1-1.3 thousand breeding pairs. Analysis of literature sources shows that breeding Pelicans first appeared in Chelyabinsk region 20-25 years ago, and since then their number has been growing steadily. We can expect an increase in the number of the species in the future. At the same time, Pelicans' high sensitivity to the disturbance factor forces them to choose protected and most inaccessible areas for breeding and prevents their dispersion over other waterbodies of the region. The paper contains 2 Figures, 1 Table and 21 References.

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