Monitoring Results of the Eagle Owl Population in the Strip-shaped Pine Forests in the Altai Kray, Russia

Abstract

Based on author’s research in 2013–2014 the paper contains information on distribution, numbers and breeding biology of the Eagle Owl (Bubo bubo) in the strip-shaped pine forests in the Altai Kray. A total of 146 breeding territories of the Eagle Owl (61.6% of the territories already known in the strip-shaped pine forests) located in the Altai Kray. Over the past 12 years the population of Eagle Owl declined by 46%. With the most considerable population lost happened after 2007 caused by the intensification of deforestation in the strip-shape pine forests. Considering this fact, we can estimate the current population of the Eagle Owl inhabited the plains on the left bank of the Ob River in the Altai Region as 233–253 (mean 240) breeding pairs. Studies have shown that by a decline in the Eagle Owl population numbers being disturbed by loggers, some pairs of Eagle Owl could move from the forest margin to its depths. In the last few years Eagle Owls begun to occupied theirs nests under the smaller trees than before (t-value=1.86, df=35, p=0.07). Breeding success of the Eagle Owl decreased from 65 to 40.6%, while the average number of chicks in broods increased from 1.87 to 3.15 nestlings to a successful nest. According to the analysis of negative factors influencing the Eagle Owl population - population dynamics of this species prognosed as negative.

Keywords

• raptors
• owls
• Eagle Owl
• Bubo bubo
• breeding territory
• Altai
• pine forests