Q: Last summer I observed a shrike in Colorado and took several photos, but am still not sure which kind of shrike it was.

A: As you probably know, there are two species of shrikes, the loggerhead and the northern. They look so much alike that they're a challenge to tell apart. A friend who's an excellent birder has a good rule of the thumb: "If you want to tell which shrike you're seeing," says Tom Bell, "look at the calendar." This refers to the fact that loggerhead shrikes are seen in our area in the summer and northern shrikes in winter. And loggerheads are the only shrike to inhabit the area of Colorado where you saw the shrike.

Crows eat in street

Q: After a recent snowstorm I noticed a group of crows at an intersection, apparently eating the salt pellets. I'd never seen birds eating salt before and wonder why they were doing it.

A: I checked with the St. Paul Public Works Department and the word is that many cities are now adding a molasses mixture to their salt. This apparently helps the salt stick to the roadway better and makes it less corrosive. The molasses in those green pellets would have a sweet taste, and this must have been the appeal for the crows you observed. Some Wisconsin cities are adding cheese brine to their road salt mix, some cities use beet juice and one town in Iowa used a local spice factory's excess garlic salt. I contacted the Wildlife Rehabilitation Center about birds eating salt, and wildlife vet Dr. Leslie Reed noted that this probably won't harm the crows, unless they eat large amounts of the salt mixture.

Bad glass

Q: A red-breasted nuthatch hit my window near the suet feeder. It lay on the deck for some time but after about an hour had flown away. Do birds recover after hitting a window and are unconscious?

A: Windows are a major hazard for birds — they kill or maim millions of them every year. Even if a bird is able to fly away, it may succumb to its injuries later, and if it has damaged its beak, which often happens, it may slowly starve to death. Since your window has been involved in at least one window strike, it would be helpful to birds to make it more apparent. I'm a big fan of the static-cling window decals sold by WindowAlert, since they're nearly invisible to humans but reflect ultraviolet light, so are seen by birds. Please also consider the "Rule of 3/30": place feeders very close to windows, so birds flying away from feeders don't build dangerous momentum, or 30 feet or more away, so they have time to notice and avoid a window.

Loggerhead shrikes are seen in our area in summer.

Flock fear

Q: A group of geese was grazing in the park behind our house when they suddenly flew up and landed in the nearby pond. A little later I noticed a bald eagle sitting on the ground where they'd been. Are geese afraid of eagles?

A: Even though they're large themselves, Canada geese have an instinctual fear of big, flying predators. When they saw the eagle flying overhead, they headed for greater safety in the water. And the fact that they all were able to fly showed the eagle that there was no easy prey in this group of geese.

Crow circle

Q: With snowy owls in the news, it reminded me of something that has puzzled me for 20 years. Driving on an airport perimeter road I saw a snowy owl on the ground, surrounded by a bunch of crows that seemed animated but not alarmed. Since crows don't like owls, I'm wondering why they weren't trying to force it to leave?

A: I would love to have seen this crow circle with a snowy owl in the center. It's possible that the crows had been noisily mobbing the owl, a more typical crow/owl interaction, but were taking a break just at the time when you drove by. Local crows may not be all that familiar with these owls from the far north, and may have been fairly sanguine about the owl since it was on the ground. They might have assumed it was unable to fly, thus not posing much of a danger. Crows always know what they're doing, but we don't always know why they're doing it.

No-birds birdbath

Q: We have a heated birdbath on our deck, but birds just don't use it in winter. There are lots of birds bathing and drinking from it in the warm months. Any ideas?

A: This seems strange, since birds usually flock to a birdbath, especially in winters like this one where nearly all other water sources are frozen over. I wonder if the birds don't feel safe using your birdbath in winter: Are there deciduous shrubs or trees nearby that provided shelter in the summer and fall? Now that the leaves have fallen, birds may feel too exposed to aerial predators. Do you have a dog that spends time on the deck, or visible cats who watch from the patio door? These might deter the birds. Finally, let's consider the birdbath basin — is it more than 2 inches deep and/or does it have slippery sides? It might be worth placing a brick or large stone in the center, to give birds good footing.

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.