By David Ryan, Field Forester
On a recent tour of Ellsworth, we were looking at marbled murrelet habitat and how we manage Ellsworth toward fostering these remarkable sea birds. Although we did not come across any murrelets, we did come across a different diminutive avian friend.
Meet the Northern pygmy owl (Glaucidium gnoma). As we peered across some drainages assessing murrelet habitat, a member of our group spotted a small, buffy-headed bird perched atop a sapling. Due to the small size, unique shape and behavior we were quite puzzled as to its identity. At about 6 to 7 inches long, we thought about finches and sparrows, not owls.
It seemed rather unperturbed by our presence and allowed us to get close enough for a positive identification.
Unlike many other owls, Northern pygmy owls are diurnal rather than nocturnal, so they hunt during the day. Cornell Lab of Ornithology describes them as ferocious hunters with a taste for songbirds. They do also eat small mammals, amphibians and large insects as well.
Despite their small size, they can “punch above their weight class” and some have been known to take quail and chickens as well! Due to their diurnal habits and reliance on vision for hunting, Glaucidium gnoma lack the asymmetrical ears and flattened facial discs that give other owls heightened aural capacity for nighttime hunting.
They are seasonally monogamous and reside in tree cavities that have been built by other species such as woodpeckers. Clutch sizes range from two to seven eggs. Incubating is left solely to the female while the male hunts and feeds both the female and the nestlings. Fledging occurs at 23 to 30 days and parental protection continues for another 20 to 30 days after the young fledge.
Northern pygmy owls reside in a variety of forest types and elevations, and they range from Canada all the way south through Mexico. Because it is uncommon to see them, surveying populations is difficult. However, they have a broad geographic range of suitable habitat and are believed to have healthy populations. Therefore, they are listed as a species of Least Concern by the International Union for Conservation of Nature. Like all owls, Northern pygmy owls are protected under the Migratory Bird Treaty Act.
Genetically, there is a possible distinction between Glaucidium gnoma and Glaucidium californicum. Some guides indicate that Glaucidium gnoma is a mountain pygmy owl that is genetically different than Glaucidium californicum, the Northern pygmy owl. Currently, Sibley Birds West, Cornell Lab of Ornithology and Audubon still classify both varieties as Glaucidium gnoma and that is the taxomic structure I have used.
However they are classified, they are an impressive little owl. Songbirds often mob around Northern pygmy owls in a defensive effort to drive them away — so, next time you are in the woods and see flocks of songbirds in a frenzy, keep your eyes peeled for a Northern pygmy owl.
While their small size may trick your eyes as to what you see, it is a treat to witness these mighty avian hunters in action.