Birding: Blue jays put on a nutty show

Q: I watch the blue jays around the peanuts I put out for them and it seems that a jay will pick up a nut, then put it down and try another before flying off to hide it. It seems they are comparing weights, is this true?

A: Yes, that's exactly what they're doing. Researchers have found that jays, when faced with a pile of peanuts, will test several nuts until they find the heaviest one. When they return after hiding the first nut under leaves or under tree bark, they go through the ritual again, taking the next heaviest, and so on until all the nuts are gone. They must feel that they want the nut with the largest reward first, in case there's an interruption, which there often is in the bird world.

You can create your own back-yard blue jay show by putting out unsalted peanuts-in-the-shell when you know jays are in the area. Kids and cats, especially, love to watch the tumult that ensues in the blue jay world. In my back yard, a group of four blue jays makes short shrift of the peanuts I place on a bench each morning. They're not the earliest risers in the bird world so I wait until the sun is well up and no squirrels are around before setting out about 30 peanuts. One by one the big birds glide in, picking up first one nut, after another, then flying off with the larger nuts first. One gluttonous bird often stuffs two into his expandable throat patch and holds a third in his beak before departing. They're so noisy that a curious cardinal sometimes comes in to observe and grabs a small peanut himself.

Q: A very different-looking house finch appeared at my feeders a few days ago. He was orange-hued where a normal finch would be red. Is this unusual?

A: Most of the male house finches we see have a great deal of red in the head, chest and rump, but this species is known to exhibit wide color variation. House finch feather color comes primarily from pigments in the food they eat, and if a house finch doesn't consume enough pigment-producing foods, such as fruit and berries, it may molt feathers that are orange, gold or even yellow. An all-yellow house finch showed up at our birdbath a couple of years ago. Some research indicates that the paler birds could be young males who may produce redder feathers as they age.

Q: What's the best time to put out my hummingbird and oriole feeders? And should I keep them up all summer?

A: These are good questions and very timely. You could put out the oriole and hummingbird feeder during the first week in May, which is when the early birds begin to migrate in. (A few hummingbirds show up in late April, so you might want to hang nectar feeders a bit earlier.)

Orioles are a slightly different story: For several weeks after they arrive, they'll visit feeding stations for grape jelly, oranges and nectar in feeders. Once they begin caring for nestlings, however, their diet changes dramatically and they feed themselves and their young almost exclusively on insects. So you could pull the oriole feeders in mid-June through the middle of July, then replace them in late July. This is the time when young orioles leave the nest and their parents often bring them to feeding stations for an easy meal.

Q: Our neighborhood group is working to remove buckthorn in a nearby city park. The woods already look much more open and we think we're hearing and seeing more owls. Should we expect to see other differences in the birds inhabiting these woods?

A: This is an excellent question and one that many people, from neighborhood volunteers to natural resource managers, have been thinking about. First, kudos to you and your neighbors for engaging in the hard work of managing this invasive species. Buckthorn has spread like wildfire after being introduced from Europe in the early 1800s, crowding out native plants and changing the soil to make it tough for other kinds of plants to grow.

Yes, you should begin noticing changes in the woods as the buckthorn is cleared out, especially an increase in "species richness" — bird species diversity declines as plant diversity diminishes. Cardinals, robins, wood thrushes and ovenbirds may move back in, since these birds search for food on the ground and find it easier to forage in areas not choked with buckthorn. Birds such as phoebes and flycatchers will also appreciate newly open areas for chasing flying insects.

Birds that nest on the ground, such as some thrushes and ovenbirds, should also return when the buckthorn is gone. So clearing out this alien is a very good thing, especially if native species are planted in its place. Removal makes it easier for owls to hunt for rodents and it may simply make it easier for you to see birds in the now-open environment. (Thanks to Carole Gernes of the Ramsey Conservation District and Lee Frelich, director of the University of Minnesota's Center for Forest Ecology, for their help on this topic.)

A: This was unusual behavior on the waxwing's part, and since no wild bird would normally be so lethargic or allow a human to approach so closely, I suspect something was amiss. The bird might have become intoxicated if the crabapples had fermented over the winter (this does happen), or it might have run into a branch or a window and was stunned. You mentioned that it later flew off, so I'm glad to learn that a predator didn't consume it while it was so vulnerable on the ground.