an average of 6.7 fledglings over their reproductive lifetime (with the most productive females producing up to 33 fledglings). Brooding activity peaks, with typically 9-14 daily visits, in Finnish studies in the late evening during spring and summer while tending to young, with a weaker peak activity time in the early morning, both timed to peak prey activity times. It is well known that mother Ural owls defends her brood in a fearsome display. In Finland, the repeatability of the nesting defense behaviour by females was ranked as 52.4%, starting with a bark and taking flight, then fly-bys towards the perceived threat and culminating in attacks and powerful strikes. Per this study, those females that laid their eggs earlier on average defended their nest more vigorously than those who laid their clutches later. The force and ferocity of the attack led to its common name in Swedish (Slaguggla or “attacking owl”), and their attacks can potentially cause grievous physical harm even to an animal as large as a human. In at least some cases, humans experience the loss of one eye or have been blinded, with broken eye sockets or eyeballs extracted by Ural owl attacks.Saurola, P. (1992). Population studies of the Ural Owl Strix uralensis in Finland. The Ecology and Conservation of European Owls, 28-31. Due to her attacks, the predation rate on Ural owl is often exceptionally low. Partial feather molting by females was thought to not have great bearing on her brooding abilities, since it was largely timed to periods where the female (and her brood of offspring) are being almost entirely fed by the male of the pair. Breeding success Broods with more than three chicks sometimes experience siblicide per study in southern Finland, but instances of siblicide are rare otherwise. Larger clutches seem to be an insurance behaviour since authors showed that broods of 4 or so were more likely to have younger sibling die sooner or later before independence. Productivity is largely associated with prey access, with the effect most studied in Fennoscandia because of the dramatic 3 year fluctuation of vole prey appears to cause great variations in productivity. Natality rates could vary from zero to 2.9 across the years based on prey numbers in Sweden, with the average being 1.03-1.12 fledglings per pair and 2.68 fledglings per successful pair. However, it was estimated in Sweden that on average 62% of owls do