In Juneau, Alaska, the barred owl when compared in a study to other owl species was considered "non-linear" in activity, with the peak discernible recorded activity time based on vocalization being right at sunset rather than after it. The mean number of prey deliveries when the young are 6–10 days old is 2.4 per night, 1.4 when they are 11–15 days old, 3.6 when they are 16–20 days old and 2.2 when they are 21–25 days old. However, in a study specifically in the eastern Cascade mountains, where the barred appeared to readily access large prey like snowshoe hares as well as flying and other squirrels, the barred owl's mean prey size was 21% higher than the spotted owls in the mountains. In Oregon, the weights estimated for ruffed grouse taken by barred owls varied enormously, from small chicks estimated at 25 g (0.88 oz), to adults weighing about 576 g (1.270 lb). , A big beech with a rotting core, encompassing a large cavity reached through a deep crevice, is an ideal nest site. Hollows or snags may be made by any variety of sources, often due to a disease or storm, with hollows and snags large enough to accommodate these birds usually only occurring in an old-growth tree. Schroeder, M. A., E. J. Blomberg, D. A. Boag, P. Pyle, and M. A. Patten (2020). However, there has been much variation described.  A study utilizing stable isotopes in Alberta appeared to confirm that the great horned owl preys on nearly twice as many prey species as do the barred owls of the area.  This species, like other forest owls, is vulnerable to the respiratory disease aspergillosis. Benjamin Chan.  Cannibalism amongst broods rarely occurs in this species.  Although they usually hunt within woodlands, they not infrequently hunt in open terrain, more typical of the hunting areas of a bird like the long-eared owl. James, S. B., Raphael, B. L., & Clippinger, T. (2000). The streaking is usually blackish, dusky brown, or sometimes rufescent- (reddish-) brown. Barrowclough, G. F., Groth, J. G., Odom, K. J., & Lai, J. E. (2011).  At least two other variations on the legato/ascending call are known.  Meanwhile, for the female, the wing chord may range from 318 to 357 mm (12.5 to 14.1 in), averaging 335.8 mm (13.22 in), the tail from 204 to 257 mm (8.0 to 10.1 in), averaging 223.3 mm (8.79 in) and the culmen from the cere 20 to 30.7 mm (0.79 to 1.21 in), averaging 25.1 mm (0.99 in).  The most widely reported nesting trees in breeding cards were elms (21%) and beeches (15%), followed by oaks, hickories, yellow birches, sycamores, aspens, maples and poplars.  The effect of other parasites are more poorly known beyond generally compromising their condition but in one case Sarcocystis may have caused paralysis in one barred owl.  The aggressive response even to known neighbors in this study is unusual.  The wing area (measured by square centimeter relative to the body mass) is quite intermediate among American owls, with the wing loading being lower than larger, but proportionately small-winged larger owls and even than some smaller owls. However, the youngsters can usually clamor back up the tree with their feet and bill, constantly wing-flapping.  Conspicuous nesting sites of barn swallow and purple martin on manmade structures and objects were revealed via video-monitoring to suffer heavy predation by barred owls.  Different studies from the west (mainly Washington and Oregon) have variously estimated the mean prey sizes for barred owls at 47.7 g (1.68 oz), 56.1 g (1.98 oz), 60.2 g (2.12 oz), 103.5 g (3.65 oz) and 123.6 g (4.36 oz).  Forest birds seem to recognize the barred owl as a threat, with mobbing behavior evoked easily by playing recordings of their calls in the daytime.  However, little is known on the feasibility or benefits of habitat maintenance that favors spotted over barred owls. Gjeltema, J. L., Degernes, L. A., Buckanoff, H. D., & Marcellin-Little, D. J.  A pilot study carried out in Humboldt and Del Norte counties killed 73 of 81 territorial barred owls that could be found. Therefore, the barred owl is considered "demographically superior".  The red-shouldered hawk averages somewhat smaller and has a more limited diet than barred owls, but probably goes after dangerous prey such as snakes more regularly. & Marks, J.S. Diller, L. V., Dumbacher, J. P., Bosch, R. P., Bown, R. R., & Gutiérrez, R. J. Smaller squirrel varieties are usually focused on when hunted as supplement prey, such as chipmunks, averaging about 83 g (2.9 oz) among the different species they prey upon, and pine squirrels, which average about twice as large as chipmunks.  The tarsi and toes are feathered up to the dark gray, black-tipped talons. Dark, S. J., Gutierrez, R. J., & Gould Jr, G. I. (1991).  The issue of temporal activities is less pertinent to the predator of flying squirrels, which are nocturnal.  This owl species currently ranges through much of British Columbia, where they have been expanding their range since at least 1943, including Vancouver Island and as far north as Fort St.  There are several records of breeding barred owls nesting successfully for a decade or more. (1983).  If a great horned owl moves into an area, barred owls appear to avoid said areas, based on radio telemetry data.  In Baker Lake Basin in California (part of the "invasive" stretch of the range), 7 females weighed an average of 805 g (1.775 lb) while 8 males weighed an average of 663 g (1.462 lb). , The ranges of pairs overlaps in the breeding season, at 87–95% range overlap, but decreases down to 45% after hatching. Several species of woodpecker are preyed upon almost throughout the range, including at least a half dozen in Oregon alone, from the smallest North American species, the downy woodpecker, to the largest, the pileated woodpecker. Who cooks for you-all?” is a classic sound of old forests and treed swamps.  The fulvous owl is usually considered distinct in modern accounts while the cinereous is recognized by the International Ornithologists' Union but not by the American Ornithological Society.  Most reported instances of such captures are of various small lizards, often of skinks in the genus Plestiodon, most often from the Midwest to the western parts of the range. (1972). (2018). A similarly high rate of local determent by barred owls has been found for other woodland thrushes like the veery, wood thrush and varied thrush, with the additional finding that pre-dawn singing by certain thrushes, when their escape abilities are dulled by the dim light, leaves them vulnerable to barred owl ambushes.