Last week’s column about the saw-whet owl banding demo generated several comments from co-workers. They were all surprised at how small this owl is.

Weighing as much as an American robin and measuring a trifle less in length, the saw-whet is not the smallest North American owl – that honor goes to the elf owl. At 53/4 inches, this resident of the American Southwest and Mexico is smaller than a European house sparrow.

There are several other small North American owls: the flammulated owl (63/4 inches), the whiskered screech owl (71/4 inches), the eastern and western screech owls (81/2 inches), the northern pygmy owl (63/4 inches), and the ferruginous pygmy owl (63/4 inches).

Logic says that birds of such small stature would catch only small things to eat: the elf and flammulated owls are almost entirely insectivorous, while the slightly larger saw-whet and screech owls prey upon small birds and rodents as well as insects.

The pygmy owls are the exception. They are aggressive owls that hunt during the day, taking prey such as mourning doves. Imagine a bird the size of a downy woodpecker hunting a bird the size of a common grackle, and you get the idea – it’s quite a feat considering their size in relation to their prey. More amazingly, although unusual, are reports of the owls’ preying upon birds as large as quail and chickens.

I guess you could say they have “little owl” syndrome.

Another fascinating characteristic of the pygmy owls involves deception. The plumage pattern on the backs of their heads resembles a pair of eyes. Researches suggest this “false face” may prevent rear attacks by would-be predators – and there are plenty of these about during the day, when the little owls are out hunting themselves. The small nocturnal owls do not have this deceptive plumage pattern.

The pygmy owls also hunt more by sight rather than by sound. Consequently, their ears are symmetrically placed on their heads. Nocturnal owls have asymmetrical ear openings; sometimes this asymmetry extends to the actual skull shape, as it does in saw-whet owls. This auditory lopsidedness enables the owls to pinpoint the direction of sounds much more accurately than a pair of normally placed ears.

We were able to view this adaptation up close at the banding demonstration. Once she had banded and measured the saw-whet owls, Audubon naturalist Judy Walker gently moved the feathers surrounding the ears aside; the right ear was at about eye-level; the left was down at about bill-level.

It is one thing to read about this; quite another to actually view it up close, in a living, breathing creature. Within moments the owl was free again. Hopefully, we’ll learn more of the mysteries of its life – and what it needs from us -as a result of the banding process. There is nothing like the natural world for teaching wonder, curiosity, and respect.

Chris Corio, a volunteer at Fields Pond Audubon Center in Holden, can be reached at fieldspond@juno.com