The success of Eagle Owl breeding in artificial niches and natural nests was studied. Manufacturing and installing artificial nests for Eagle Owls in Mordovia, central European Russia is employed as a factor to increasing the number of both successfully breeding pairs and the population size. At the same time, no differences were found for artificial and natural nests in terms of reproductive success, clutch size, and the number of fledglings. In 51% of nesting cases, pairs laid three eggs, compared to two eggs in 43% or four eggs or one egg each in 3%. The average clutch size was 2.54 ± 0.08 eggs. Over the years of our study of owl nesting in Mordovia, 13.6% pairs raised one chick, compared to two and three chicks in 36.4 and 50%, respectively. The number of reared chicks per successful nest averaged 2.36 ± 0.11. The mortality rate in nests was lower in artificial nesting sites (30%) than in natural ones (40.6%).
Lapshin A., Andreychev A., Alpeev M., Kuznetsov V. Breeding success of the Eurasian Eagle Owl (Bubo bubo, Strigiformes, Strigidae) in artificial nests // Biology Bulletin. 2023. V. 50. № 7. P. 1486–1492.