Why did the hawk divebomb the turkey?

Q: I watched a turkey being harassed by a red-tailed hawk recently. The hawk would dive at the turkey without hitting it, which didn't seem to bother the turkey much. Is this normal behavior?

A: It seems unusual to me, since a red-tailed hawk almost surely couldn't carry off an adult wild turkey. This raptor probably had something else on its mind. It's possible that the turkey was a female protecting her brood of chicks and maybe they were hiding in the grass and not visible to you. The hawk also might have been trying to drive a youngster into the open so he could snatch it. Female turkeys are very good parents and work hard to keep their broods out of the clutches of predators. Her apparent lack of concern might have been hyper-vigilance. (If readers have other theories, I'd love to hear them.)

Beak too small?

Q: Looking at my backyard chickadees, it's hard to believe that they can drill a hole in a tree with those tiny beaks. Woodpeckers I can understand, but not these little guys.

A: Chickadees are cavity nesters, and are capable of carving out their own holes in trees. You're right that, unlike woodpeckers, they can't drill straight into wood; instead they search for a well-rotted snag or a tall stump. Their nest-building efforts involve pulling out decayed wood to form a hole, then carrying the sawdust some distance away (so predators don't catch on). Even better, from a chickadee's point of view, is to find a human-made nest box, ready for occupancy.

Hoping for hummers

Q: I didn't see any hummingbirds last summer and wonder if I should bother putting up the sugar-water feeder this year.

A: I'd recommend hanging out your feeder this spring, because it's entirely possible that some hummingbirds might stop by during migration. You'll have the most success in attracting hummingbirds if you consider your feeder one element of a complete habitat. The tiny birds spend a lot of time perching, so place the feeder near a small tree or arbor. They appreciate some shrubbery or evergreens for hiding, and they have an affinity for moving water, so a birdbath with a water feature is a good idea. Plant clumps of bright flowers in your gardens for natural sources of nectar.

Bluebird competitors

Q: How do I stop little brown birds from making nests in my bluebird house?

A: Those little brown birds are probably house sparrows, and bluebirds and sparrows are a very bad mix. Sparrows are cavity nesters, just like bluebirds, and will pierce eggshells and even kill female birds on their nest in order to commandeer a cavity. This has happened on my bluebird trail and it's terrible to see. You need to evict the sparrows each and every time they attempt to build a nest by tossing out nesting material as they bring it in. (Sparrows are not a native species, so are not protected by laws designed to protect migratory birds.)

Are juncos late?

Q: We had juncos in the backyard very late this year, and I'm wondering if they might decide not to move back north at all.

A: Even though juncos breed in the boreal forest, we often still see a number of them well into spring. A friend who keeps track of such things has recorded seeing his last junco as late as early May. They tend to depart just as the yellow-rumped warblers begin to flood in.

Birds and weather

Q: It seems that bird migration continues to occur on schedule each spring and fall, so I'm wondering if all the talk about global warming is irrelevant to birds.

A: The warming of our planet is already affecting birds, to the point that the Audubon Society lists hundreds of species as potentially "climate-threatened" or "climate-endangered." Many birds are arriving on migration weeks earlier than they used to, with profound implications for their survival.

For example, warblers arrive just as spring's caterpillars, a major food source, are hatching. Climate change is destroying this synchronicity, with the birds sometimes arriving before insects hatch, or insects sometimes hatching before migration.

Our warming climate is causing breeding ranges to shift, as well, often with negative results. Take the tree swallow: As the birds follow warming trends north, they move into areas where trees are scarce, bad news for a species that nests in tree cavities.

Audubon says more than 300 species of birds in North America will be profoundly negatively affected by climate change by the end of the century.

St. Paul resident Val Cunningham, who leads bird hikes for the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at valwrites@comcast.net.