Birding Q&A: Catbirds head to winter homes

Q: Where does my gray catbird go for the winter?

A: These perky songbirds are gone from our back-yard thickets and tangles and are heading toward winter homes along the Gulf Coast, on Caribbean islands, Central America and especially Mexico, where nearly a quarter of them end up. Catbirds are much more likely to be found in forests on their winter grounds than during nesting season.

Q: Watching my hummingbird visitors this summer, I wondered why they came looking for me when I was sitting inside, behind the patio door, but ignored me when I'd be sitting outside? They were very tame and friendly.

A: I'm intrigued by the idea that your hummingbirds seemed to come searching for you when you were indoors. I've heard of hummingbirds doing this kind of thing when feeders are empty, but it doesn't sound as if that's the case here. It's possible that they were seeing a reflection of your feeders in the patio door. I don't mean to intrude on your perception that hummingbirds are tame little birds. But everything I've read about the little dynamos indicates that their dominant characteristics are fearlessness and fierceness. There are so many variables in the world of birds, however, that just about anything is possible.

Q: In late afternoon or early evening I sometimes hear a bird that makes a sound like a dull cluck, repeated over and over. Any idea what that might be?

A: My first thought when I read your description was a chipmunk. They're known to make a sound that some describe as a "chuck," others hear as "chip," over and over again. Just to be sure, I asked several birding friends and they had the same thought. The little rodents will be heading down into their burrows soon, so you won't hear them again until next spring.

Q: We observed a young Cooper's hawk bathing one day in the birdbath, then it landed on our fence to dry and preen its feathers. Oddly, the hawk kept opening its mouth as if to yawn as it looked around. Can you tell us why it did this?

Q: Since migration is so dangerous for birds, I've always wondered why some of them do it. Why don't they just stay all year in tropical areas?

A: That's an excellent question, and it's one that bothered ornithologists for a long time. Part of the answer has to do with local resources: We think of the tropics as lush and abundant, but in reality there simply isn't enough space and food for billions of birds to raise their young. So birds fly north to take advantage of North America's large open spaces and forests, where they can carve out a territory and feast on the insect "bloom" of spring and summer.

Several recent studies seem to suggest that songbirds originally lived year-round in North America, but began migrating farther and farther south over time, pushed by weather and other factors. They spent part of the year in the tropics, but migrated northward when breeding season approached. And that's the behavior we're seeing today.

Q: In winters with little to no snow, how do birds keep from dying from thirst, when all the water is frozen solid? Shouldn't Audubon or another conservation organization lead a campaign to provide winter water sources for birds?

A: I salute your concern and compassion for birds, but I don't think you need to fret about this aspect of their winter survival. Birds and mammals are adept at finding seeps, springs and unfrozen areas in lakes and ponds to acquire water if there's no snow to eat. I see proof of this each December, during the Audubon Christmas Bird Count. My count area includes parks along the river where water trickles out of the hillside, and counters can always find a wide variety of birds there.

Q: Sparrows are a real problem at my feeders and I'm wondering whether a feeder with a wire cage around it would keep them out.

A: Before spending the money to buy such a feeder, I'd ask the store selling it whether it's a sparrow stopper. I've never used such a feeder, but in checking several products online, I don't see any that make claims about keeping sparrows out; they're designed to stop squirrel raids. It seems as if sparrows could easily land on the outer cage, then wiggle inside.

Note to readers: After noting the item in a recent Question and Answer column about a sandhill crane walking down a Bloomington street, a reader in Plymouth sent a photo of a sandhill crane family feeding on raspberries and bird feeder seed in his back yard.