Q: There was a great horned owl nest in a tree in our local park, and the young owls attracted a lot of human interest. Some days there would be 30 people gazing up at the owl family. I'm wondering whether this disturbed the owls.

A: That's an excellent question and for answers about "owl etiquette" I asked the experts at the Raptor Center.

There's no legally defined distance that people must stay away from an owl's nest tree, "but if human activity causes nest failure or injury or death of a chick, it is considered harassment, which is illegal," says Lori Arent, clinic manager at the Raptor Center.

She notes that raptors increasingly are nesting in parks, golf courses and even back yards so this kind of question comes up more and more often. "Great horned owls are fairly tolerant of human activity," Arent added, "but at dusk and during the night they become very aggressive in defense of their young. A human venturing too close to a chick at these times could be injured by an adult owl."

Her advice: Admire owls from afar. Keep a respectful distance and enjoy the sight of young owls through binoculars or a long camera lens. And if you discover a young owl on the ground or on top of playground equipment, leave it alone and call the Raptor Center for guidance (612-624-4745). Young owls learning to fly may tumble to the ground or grab onto a swing set, but they don't stay in any one place for very long.

Locating owls

Q: I'm a big fan of owls and wish I knew where I could watch them. I'm wondering why someone hasn't created a website that shows where owls are being seen.

A: Many of us are intrigued by owls, and that's the problem: We tend to love them too much. Some people get too close to these wild birds, intruding on their space and making them feel unsafe. For this reason I don't think you're going to find an owl locator site online. Spotlighting specific owl nests would bring big crowds to the trees where owls are living, possibly creating an intolerable disturbance for the owl parents. We each have to find our own owls in woodlands and open areas. Or, you might consider participating in the Western Great Lakes Region annual owl survey. Find out more at: www.hawkridge.org/research/springowl.html.

Wrens and spiders

Q: When I was cleaning out my wren house last fall I found many old spider egg sacs inside. Why would spiders lay their eggs in a wren nest?

A: You've observed an intriguing facet of house wren nest building. These tiny birds build their stick nests in a tree hole, nest box, crevice, even an old shoe or box in an open garage. They don't consider their job complete until they've collected spider egg sacs from around the yard and stuffed them into their nests. They do this to create a natural insect repellent: Once the spider eggs hatch, the young spiders will consume the mites and other pests that might feed on the wren nestlings.

Busy woodpeckers

Q: Woodpeckers seem to expend a great deal of energy for not much reward. Do they really survive on the insects they dig out of a tree?

A: You're right, woodpeckers work very hard to extract wood-boring beetle larvae and ants from beneath tree bark. But this can be more rewarding than it looks, because many larvae, which the woodpeckers detect by listening to them chew through the wood, are fairly large and packed with protein. Woodpeckers sometimes favor smooth-barked trees, since these are easier to drill into. And dead or dying trees, whose wood is more easily bored into, are especially favored, since these are rife with insects.

Foxy sparrow

Q: It was fascinating to watch a bird this spring that I'd never seen before, but I'm stumped on what kind it was. It has a brown and gray head and reddish back, with a very streaky chest and a long tail. It scratched on the ground like a brown thrasher, but wasn't that large.

A: You were observing one of my favorite springtime migrants, the fox sparrow. These are one of the first birds to show up after the snow recedes and they're famous for their skip-forward/hop-back foraging style. They toss the mulch in my garden beds all over the place with their hopping, but spend most of their time under my spruce tree. The fox sparrow's lilting song can be heard here: www.allaboutbirds.org/guide/fox_sparrow/sounds.

Evict the sparrows

Q: I have three of those 12-unit purple martin houses at my lake place. All units are currently occupied by sparrows. Should I lower the houses and clean out the sparrow nests or will the martins kick the sparrows out on their own?

A: If you want purple martins to use your nest boxes, then you'll have to evict the sparrows and keep them out. House sparrows are vicious competitors for nest box space and have been known to injure or even kill other birds to drive them off. It may already be too late for this year, but if you want martins next year, you'll need to keep sparrows out of the apartments. Find out more about martins vs. sparrows at these sites:

www.purplemartins.com/Topics/starling-sparrow-wars.htm

http://tulsaaudubon.org/housesparrow-starlinginfo.htm

St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at val​writes@comcast.net.