engleski

Gniježđenje gačca Corvus frugilegus u Osijeku i Vuki tijekom 2014. i 2015. godine i njegov dugoročni trend populacije

The breeding population of Rook was studied during 2014-2015 in the city of Osijek and the Vuka village. In total, 902 breeding pairs were counted in 14 colonies in 2014, while 928 pairs were counted in 13 colonies in 2015. Over one half of the colonies (ten colonies in 2014 and six colonies in 2015) were classified as small (below 50 pairs), with an average of 24.5 and 19.1 nesting pairs respectively. The number of medium- sized colonies (50-100 pairs) varied between one in 2014 and four in 2015, while two big colonies (over 100 pairs) were present in both years. During the past 23 years, the breeding population trend showed a moderate decline (p < 0.01, y = – 0.0186, SD = 0.0060), mainly due to the harassment of the colonies, the destruction of nesting sites, and disturbance during breeding.

vrana gačac ; gnježđenje ; populacijski trend

nije evidentirano