to breed due to lack of acceptable nest sites. Besides the unquantifiable threat of global warming, loss of old forest with dead trees with ample cavities is the species' main threat. This is especially prevalent during forest management historically and the practices of forestry departments have often favored tawny owls and been detrimental to populations of Ural owls. However, in Hedmark, Norway, the placing of 80 nest boxes did not increase the country’s Ural owl population, with only 4 of the boxes used. 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. Prior studies, in central and eastern Norway, somewhat more westerly into Norway than previously thought but not an extensive range, with the clutch size being smaller, at a mean of 2.85, within Scandinavia compared to 2.93 in Sweden, 3 in southern Finland and 3.92 in northern Finland. Eggs and young The clutch size is typically 3-4 (rarely from as few as 1 to as many as 6), with the eggs being pure white and quite rounded. The mean egg laying dates in Fennoscandia are between mid-March and late April. In montane Slovenia, somewhat surprisingly, it is slightly later at late March into early June. Mean clutch size was found to be 2.93 in Sweden. Mean clutch size in Finland was 2.24 but could range from 2.08 to 3.98 on average in poor and good years for vole prey.Pietiäinen, H., Saurola, P., & Väisänen, R. A. (1986). Parental investment in clutch size and egg size in the Ural Owl Strix uralensis. Ornis Scandinavica, 309-325. Mean clutch size in Slovenia is about 3.3. 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. Clutch size in a small sample from Nizhny Novgorod Russia was found to average 3.6. The clutch size average in nest boxes of Samara Oblast was 2.4. Egg sizes are usually between in height by in diameter, and the eggs weighing on average about when fresh. Based on studies in southern Finland, amongst 59 studied females, egg size varies by 22.4% through the cycle years and the largest eggs are roughly twice the mass of the smallest, a very considerable variation. The eggs