In my column this morning (StarTribune Home and Garden section) I stated that Snowy Owl is the largest North American owl. Reader John Oldendorf of Lake Elmo sent me an email questioning that. He said he thought Great Gray Owls held that honor.

Well, it depends on what you're measuring, weight or length. Female owls are larger than males, regardless of species, so these numbers refer to females. Information comes from the owl monographs in "The Birds of North America" series, and from The Peregrine Fund internet page.

Snowy owls average 28 inches in length, and five pounds in weight. They are the heaviest of the three largest North American species.

Great Horned Owls can be as long as 25 inches (no average found), and have an average weight of 3.9 pounds.

Great Gray Owls grow to as much as 33 inches long (again, no average found), making them the longest of the three, but have an average weight of only 2.8 pounds.