Please Feed the Birds (why some birds migrate)Archived Message
Posted by sleuth on February 3, 2011, 9:54 am
Posted on Thu, Feb. 03, 2011
Why do some birds migrate, while some hang around for the winter?
Q. Why do some birds stay here for the winter and not migrate? -- Sister Helene Schneider, of Belleville
Q. Where are the birds? Last winter I always had lots in my backyard. I saw some several weeks ago, but I've seen none for a month. -- Ron Logsdon, of Breese
A. When it comes to food, birds are a lot like people in some respects.
If we just want a quick burger, any fast-food joint will often do. But if we want what we feel is the absolute best barbecue or Cajun, we often head south to Memphis and New Orleans. The same is true for our feathered friends, says Michael Macek, curator of birds at the St. Louis Zoo.
"Generally, the only reason birds migrate ... is a food source," Macek told me. "So, it's really not related directly to the weather. Most of them can thermal-regulate (adapt to the cold) just fine. It's just the fact that there's no food source for them in the wintertime, so they move."
Perhaps the best example is hummingbirds, according to the Zoo's FAQ page at www.stlzoo.org/education/wildlifequestions.htm. If you're a fan of these tiny, beautiful creatures, you know how they hover in midair while they suck the nectar from flowers. But once the flowers die, they must head south for more. Some as many as 2,500 miles one way from Alaska to the southwestern United States. The same is true for insect-feeders and those majestic bald eagles that come south to our neck of the woods. But birds that can exist on seeds, nuts and the like can stay put.
"For example, someone told me the other day that they still have bluebirds in their backyard," Macek said. "Well, bluebirds normally would not winter here but if they have a reliable food source, they could winter here just fine because, again, the temperatures aren't the issue. It's the food."
You're probably asking about where they sleep because you don't see them roosting in the bare trees. Well, birds aren't bird-brained in the usual negative sense. First, they don't sleep as you and I do, Macek said. They certainly have periods of inactivity, but they don't fall into a deep sleep where they dream of winging their way to the Caribbean. To rest, they find shelter that hides them from predators -- and your sight as well, unless you look closely.
"It varies, but small perching type birds generally like to roost in a 'shrubby' tree or plant or a conifer," Macek said. "They can get into it and it kind of shields them from the wind and, of course, shields them from potential aerial predators like owls. So, they'd be inside of yews or spruce trees or pines."
A dearth of birds in Clinton County? Most likely just a momentary lull, Macek said.
"Birds are constantly on the move," he said. "You could have 100 birds on your feeder one day and then have none the next because they've moved someplace else or they're utilizing a different food source. There's nothing to suggest that there's any kind of trend there."
If you are going to put out feeders, try to keep them stocked -- but don't risk breaking your neck by getting out on the ice and snow, Macek advised.
"Yeah, the birds do come to sort of rely on those as food sources, so, yeah, I'd keep putting food out," he said. "But rest assured your feeder isn't the only feeder they're visiting, so if you don't manage to get out there today, believe me, they've identified a number of other food sources in the general area that they're utilizing."
Send your questions to Roger Schlueter, Belleville News-Democrat, 120 S. Illinois St., P.O. Box 427, Belleville, IL 62222-0427 or e-mail rschlueter@bnd.com or call 239-2465
on February 3, 2011, 9:54 am