The Results of Attracting of the Ural Owl to Breeding in Nestboxes in the Izdrevaya River Basin (Novosibirsk Region, Russia)

Abstract

This article summarizes data obtained during the 5 years nestboxing project aimed to multiply breeding population of the Ural Owl (Strix uralensis) in the basin of Izdrevaya river, Novosibirsk region, Russia in 2012–2016. From 2012 to 2015 a total of 38 nestboxes (NB) were installed. The distance between neighboring NBs vary from 0.58 to 1.80 km (n=24), 1.12±0.29 km average. From breeding season of 2013 to breeding season of 2015 the number of NB in project grows from 18 NB to 33 NB, however only 4–5 of them were occupied each year. Only in breeding season of 2016 we observed population growth when 8 out of 38 (21.05 %) NBs were found occupied by the Ural Owl. The average clutch size was 3.17±0.98 eggs (n=6; min 2, max 4 eggs). The average brood size was 2.00±0.58 nestlings (n=7; min 2, max 3 nestlings). The distance between neighboring pairs breed in nestboxes ranged from 0.92 to 6.25 km (n=15), 1.87±1.30 km at average. We used discriminant analysis to estimate the role of landscape on owl preferences when choosing NB and to make predictions on a future distribution of owls. The resulting discrimination function allows us to classify correctly between empty and occupied NBs with accuracy of 81.85%, Wilki’s Lambda = 0.67 (classification accuracy 81.58 %, р<0.13, F(8.29)=1.75), however, the level of discrimination is low, which indicates the close characteristics of the entire system of NBs. Applying GIS-analysis we revealed 37 potential breeding territories on a territory of 116.7 km2, only 15 (40.54 %) of them equipped with a NB. We expect that up to 25 of this potential breeding territories could be occupied by owls in the future.

Keywords

• пернатые хищники
• совы
• длиннохвостая неясыть
• Strix uralensis
• гнездовые ящики
• совятники
• Издревая
• выбор гнездовых местообитаний