You're lucky to spot an owl on its nest, but don't disturb it

High in a tree sat a great horned owl, atop its nest cavity. Two young birds occasionally struggled into sight, but all I could see were their scraggly heads, eyes and bills.

Their eyes were yellowish-hazel, deep in black sockets. Researchers say this color indicates the birds were 2 to 3 weeks old. Those eyes would soon turn gray, then brilliant owl-yellow when the owlets were 30 days old.

I assumed the great horned owl was female. They tend babies. Males, the hunters, are on the night shift, supporting the family, so to speak.

A birding friend told me he'd seen the owls in a Twin Cities park in early May, which would be late for great horned owls to hatch. My friend thought this may have been a second nest. Great horned owls usually start nesting in January or February. Perhaps the first clutch of eggs was lost to our rough winter weather.

I went to check it out. The owlets did seem small for this time of year.

The mother owl was standing guard. Basically, what she does is keep watch, along with the occasional grooming, stretching and even sleeping a bit. While her owlets are young, she won't leave them alone. They're vulnerable to predation. In fact, crows eat baby owls.

Of course, great horned owls eat many things, including other great horned owls. They are opportunistic hunters, varying their menu with the geography.

The reintroduction of peregrine falcons here and elsewhere was sometimes difficult because night-hunting horned owls killed roosting falcons.

Some birds of prey hunt from the air, but great horned owls hunt from a perch. Exceptional vision and hearing give the owls an effective hunting range of about 100 yards. When prey is detected, the owls fly in for the kill, their soft feather edges silencing the sound of their flight.

They can kill with their strong feet, their talons snapping the spines of their prey. As much as 28 pounds of pressure would be needed to open the clenched talons of a great horned owl, which often removes the head of its kill.

This owl species can live for more than 20 years and researchers say they might mate for life.

Great horned owls can be found from the Arctic tree line to central Mexico and shore to shore. But while their population is wide, it's thinly spread.

The concern is that visitors will disturb the owls. If flushed, the mother owl would have to spend energy finding a new roost. It would expose itself to harassment by other birds (crows), and its young to predation.

So seeing an owl is an uncommon privilege, a nesting owl even more so. If you do happen upon a nest, be quiet and discreet. Don't "Hoo!," wave your arms or do anything else to attract the mother owl's attention. Disturbing an owl at any time is an ignorant and selfish act.

Don't doubt it — the owl knows you're there. It just might not give a hoot.

Lifelong birder Jim Williams can be reached at woodduck38@gmail.com. Join the conversation about birds in your backyard and beyond at startribune.com/wingnut.