Page 187 - Proceedings of the State Natural History Museum. Issue 37 (Lviv, 2021)

186 Khymyn M.V.

As can be seen from table 3, the migration dates of these birds have a slightly wider date
range than the dates shown in figure 1. Because table 3 shows the dates of day and night
registrations of birds throughout the National Park, and figure 1 – only the dates of visual
registrations at one observation point.
The time of autumn passage of the Common Crane in the National Park is slightly
different and has a narrower date range than in the Volyn region (average date of beginning
migration – 25 September, lim: 25.VIII-31.X, n=79, and ending – 13 October, lim: 15.IX-
18.XI, n=54) and other adjacent regions of Ukraine [1] and strongly different (earlier
passage) than in the Central and South of Europe, as in Hungary [21] and Italy [17] in
particular.
Dynamics of passage during light part of a day is one of the most important characteristics
of bird migration (table 4).
Table 4

Dynamics on passage of the Common Crane during light part of a day
in autumn 2012-2017

Total Hour Year
number 2012 2013 2014 2015 2016 2017 Total
of birds (%) 1 1,4 - - - - 3,1 1,1
that flew 2 - 42,1 - - - 0,2 5,2
during 3 - - 2,5 - 0,4 - 0,4
one 4 1,4 - - - 0,5 - 0,2
observatіon 5 6,7 8,5 - 4,0 7,9 10,9 6,7
hour 6 7,0 - 12,2 3,6 7,9 2,9 4,9
(morning 7 - 8,5 7,4 - - 11,1 5,6
and day – 8 - 16.0 - - 0,5 - 2,0
№ 1-11, 9 - 7,3 - - 22,9 - 12,6
evening – 10 49,1 7,9 41,2 42,6 - - 12,1
№ 2-1)
11 - - 23,3 - 7,9 - 4,1
2 12,3 - 7,9 - 52,0 22,5 13,8
1 22,1 9,7 5,5 49,8 - 49,3 31,3

The Common Crane is a diurnal and partly nocturnal migrant. The majority of them flew
in the 5 last hours of observations (77,9% of all counted birds during 6 years) and the peak
of its passage occurred in two evening hours mainly (see table 4). In addition, some birds
continued to migrate in the evening and at night, they were were not visible, but their voices
were heard. Therefore, the number of migratory cranes was greater then we counted during
the light part of day.