Original scientific paper
Breeding of Rook Corvus frugilegus in Osijek and Vuka during 2014 and 2015 and its long-term population trend
Alma Mikuska
orcid.org/0000-0002-4825-7089
; Sub-department of zoology, Department of Biology, Josip Juraj Strossmayer University of Osijek
Antonija Felja
orcid.org/0000-0002-3469-3189
Tibor Mikuška
; Croatian Society for the Bird and Nature Protection
Abstract
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.
Keywords
Hrčak ID:
153111
URI
Publication date:
18.2.2016.
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