Snow a mixed bag for birds

By John Holyoke, BDN Staff
Posted Feb. 18, 2011, at 7:27 p.m.

Many of our state’s birds — like a significant portion of our human population — spend only a portion of their time in Maine.

The rest of the time (like the human snowbirds), those lucky ducks (and woodcock and robins) are down South, having fun in the sun.

But some of our bird species can be considered true Mainers: They remain here during our brutal winters, try to find ways to cope with the piles of snow, and, you might suppose (since they’re true Mainers), gripe to their fellow birds about how hard the sledding has been.

Brad Allen, a wildlife biologist who serves as bird group leader for the Maine Department of Inland Fisheries and Wildlife, says that various conditions favor some birds over others. As one species struggles, another may flourish.

You might even say (if you’re not averse to ruining perfectly good cliches) what’s good for the goose might not be as good for the merganser — or something like that.

“It’s been a challenging winter, I think, for birds,” Allen said. “And it’s been an interesting one.”

Allen said a number of species have faced tough conditions at different times this winter. At other times, snow conditions have changed to make their lives easier.

Among those species that seem to have struggled in the Bangor area are the common birds that frequent backyard feeders.

“Several people have called and said they’re not seeing the birds at their bird feeders that they normally do,” Allen said. “In the beginning of the winter, we said, ‘Just wait a minute and they’ll show up.’”

Now, two solid months into winter, Allen has backed off that assessment.

“They really haven’t shown up,” he said. “A lot of the typical birds that you feed, I think their numbers are down. It’s just a natural cycle of things. There’s not a shortage of blue jays and chickadees and nuthatches out there. But it seems like the number of finches and all are down.”

Another true Mainer, albeit with some stocking help from the DIF&W, is the wild turkey. Allen said he’s been watching a neighborhood flock of turkeys that recently grew from 30 to 60 birds.

Then, they left.

“They were under my bird feeders for several days before that really bad weather a week or 10 days ago, when we had a lot of fluffy snow,” Allen said. “Then they didn’t show up for four or five days.”

Allen’s explanation: Like many Maine motorists, they simply wandered off and got stuck, unable to return to the food of the feeder.

Turkeys can survive for quite a while in fluffy snow that limits their mobility, Allen said, before the situation gets dire.

“They say turkeys will actually sit on roosts for almost two weeks before they just start keeling over and starving to death,” Allen said.

That’s more of a threat to turkey flocks in states such as Vermont, which are farther from the coast, Allen said. In much of Maine, the normal freeze-and-thaw cycle tends to favor turkeys.

And after a recent thaw-and-freeze, that’s what he’s seeing: The flock is back, hungry as ever.

“Now there’s a crust [on the snow] and they’re just running on top,” he said.

While that crusty snow has provided a welcome highway for tromping turkeys, Allen said another popular game bird faces challenges when snow hardens up.

“When this crust evolved as a result of this last weather pattern in the last week, I was thinking, ‘I wonder if that will inhibit grouse from getting in the snow?’” Allen said.

Allen explained that ruffed grouse use fluffy snow as an insulator and hunker down in it to avoid detection from predators. When the snow’s crusty, they can’t do that.

“A lack of snow compromises [grouse] a little bit. Crusty snow compromises them. But as long as somewhere in this great state we have conditions that they can still get under the snow, it keeps them warm and it protects them from predators,” Allen said.

While grouse are looking to stay warm and avoid being eaten, they are able to eat plenty of buds off trees, Allen said.

For another species, food procurement has become an issue.

Allen said that he, along with fellow biologist Danielle D’Auria, recently rescued a bared owl from the Penobscot Energy Recovery Company plant in Orrington.

“The owl got in there to eat mice,” Allen said.

He said that bared owls have special dietary requirements that are hard to fulfill when the snow is deep.

“They’re little-mammal-eaters,” he said. “You take a Cooper’s hawk or a sharp-shinned hawk that might zing by your bird feeder looking for little birds, but owls, this particular species, needs mammals to eat.”

And since all the little mammals are cozily ensconced under the snow, barred owls are getting hungry.

Allen said he and D’Auria took the owl to Avian Haven in Freedom, a facility that rehabilitates birds.

“He was the 20th one there,” Allen said. “So owls are struggling.”

http://bangordailynews.com/2011/02/18/outdoors/snow-a-mixed-bag-for-birds/ printed on December 17, 2014