[138] Despite the different preferred forest habitat, 46.3% of ranges of Ural and Eurasian pygmy owls overlapped in Slovakia. Mate retention in Fennoscandia was found to have averaged 98-100% in males and 90-95% in females, making it amongst the most monogamous birds of prey of any order (or at least well-studied bird of prey species). It is quite possible that is to some extent a still-hunter, perching for some time on a prominent tree until prey becomes apparent into the vicinity. Being much larger and (based on morphology) presumably much more powerful, the eagle-owl is able to take much larger prey than the Ural owl. The lack of success for Norwegian populations is thus not seemingly due to a lack of nesting sites but is theorized to be more so correlated with a poor prey population for them. The phrase repeats at intervals of several seconds. [29][106] In the relatively northerly Latvia, of 2615 prey items, voles constituted just over half the diet and the prey base was relatively diverse. In particular, thrushes of the Turdus genus were the most reported prey genera in these years, averaging 19.4% by number and 23.6% of the biomass. Allen, M.. & Ward, M. & Juznic, D. & Krofel, M. (2019). [76], The Ural owl is often considered nocturnal with peaks of activity at dusk and just before dawn. [140] Nests on stumps were recorded twice in Hokkaido but otherwise Japanese Ural owls appear to rarely use such nest sites, favoring variously tree cavities, birds’ nests and nest boxes with little evidence of a strong preference of any one type of nest site. Food was also offered to pairs at nearby release pens and 60 nest boxes erected to compensate for lack of nest sites, especially in areas of secondary forest. [164] Another Slovenian study showed a fairly lower mean clutch size of 2.4 with evidence that clutch was reduced by low food access in the early part of the breeding season. [8] Use of 15 total nest boxes in Akademgorodok, Russia over three study years varied wildly based presumably on prey population cycles with anywhere from 0% to 50% used annually. [91][117] The most birds reported in the diet of Japanese Ural owls were from 36 pellets found in Sakaide, Kagawa, which mainly comprised small birds, in particular the Eurasian tree sparrow (Passer montanus) (at 78.6% by number) and the white-cheeked starling (Spodiopsar cineraceus) (3.6%). Brommer, J. E., Pietiäinen, H., & Kokko, H. (2002). Furthermore, hawk-owl’s stronger tendency for diurnality may further provide a degree of partitioning. The mean size of mountain hares taken in Finland have variously been estimated at 173 to 2,000 g (0.381 to 4.409 lb), with a common median being about 500 g (1.1 lb). Females laid eggs in Finland an average of 2.7 times in their life and produced an average of 6.7 fledglings over their reproductive lifetime (with the most productive females producing up to 33 fledglings). Like most Strix species, it has a broad, rounded head with a correspondingly round facial disc, barring a tiny V-shaped indentation. (2000). Meanwhile, the tarsi and toes are covered in greyish feathering and the talons are yellowish brown with darker tips. Ural owls are not known to attack prey from active flight, instead nearly always dropping down on it directly from its perch. All told from the entire Bavarian reintroduction, it was said that the owls producing a total of 204 offspring between 1972 and 2014, although many of these may not have survived. [199] Prospects for breeding are generally low during the low point of the three year cycle of the vole prey of Urals in south Finland but paradoxically when a high vole year is followed by a low one, the number of attempted clutches is higher but the rate of nest failure is higher.