The Solstice has come and gone, officially ushering in winter and its many attendant flora and fauna. The shorter days and longer nights of January are ripe for those desiring intimate glimpses of our mostly nocturnal hunters: the owls.
Given our much-vaunted biodiversity in other taxonomic categories, it should come as no great surprise that we also host a good number of these denizens of the dark. They sometimes haunt our minds and imaginations as much as they do local habitats, but “hoooo” are they?
We’ll focus on just two of our eight – ten wintering species – the barn owl and the great horned owl. The remaining cold-weather species include: Mexican spotted owl, long-eared owl, western screech owl, whiskered screech owl, northern pygmy owl, and possibly flammulated, saw-whet, and short-eared owls in some years.
Our owls fall into two separate families – the barn owl family and the true owl family. The former consists of just one local species – the rather cosmopolitan barn owl – as well as about 17 species found in other biogeographical realms. All are variations on a narrow theme – highly nocturnal species with a pronounced facial disk that aids their hyper-acute hearing.
Owing to this auditory prowess, barn owls in studies consistently catch mice in complete darkness. Indeed, small rodents comprise most of their fare, which seems like fairly small prey for a species that averages over a pound in weight. In addition to using old human structures for nesting and roosting, barn owls also employ dense trees and various grottos for these crucial behaviors.
Given their highly secretive nature, we humans must rely heavily upon vocalizations to find and identify owls. One of the main calls of the barn owl is an otherworldly, bloodcurdling hiss that may lend credence to the idea that this species spawned many a ghost story. Paired with their pale appearance, near-silent flight, and use of old buildings, this idea gains much traction. Case in point: an alternate name for this species is demon owl.
The great horned owl is an “eared” owl, sporting feather tufts where many mammals instead show ears or horns, hence the misnomer. These protuberances provide some camouflage and even size in a showdown with a competitor or predator. Great horned owls range from Alaska to Tierra del Fuego. They are also the largest local species of owl and hence the strongest and fiercest. A female, which are generally larger in owls, can weigh over 3.5 pounds and subdue prey as big as skunks – whose olfactory-aimed defense is of little avail here, foxes, 20-pound wild turkeys, other owls, hawks, and even (rarely) roosting eagles! Truly, great horned owls rule the night skies. A wide range of smaller prey, nonetheless, is more typical.
January is courtship and egg-laying time for this species, as getting a head start on the growth of their nestlings seems to be a key evolutionary strategy. This may allow the adults to feed the nestlings and fledglings more efficiently, given the often abundant avian and mammalian prey – young and inexperienced birds and mammals in particular – available in late winter and early spring. Additionally, securing a nest before other raptors generally ensures that competing hawks and eagles will be unsuccessful in trying to dislodge great horned owls from their reproductive site. Listen for their distinctive “hoo-ho-hohoo-hoo” vocalizations this month.
What about the interactions of these two local owls? When barn and great horned owls meet, either the bigger great horned eats its smaller cousin or chases it away from its territory. Clearly the ghost has met its match!
Vincent Pinto and his wife, Claudia, run RAVENS-WAY WILD JOURNEYS, their Nature Adventure & Conservation organization devoted to protecting the unique biodiversity of the Sky Islands region.