Even if you did get an A in ornithology as recently as five years ago, Rich Guthrie suggests that most birdwatchers should take a refresher course.

“Climate change is happening, and it’s happening at breakneck speed geologically speaking,” said Guthrie, a retiree from the state’s Department of Environmental Conservation and one of the Capital Region’s top authorities on birds. “Those dramatic changes are very clear when you look at the migratory habits and nesting ranges of birds. When I was younger, it was big news to see a cardinal at a feeder in the middle of the winter. Now? Well, I love seeing 20 cardinals at my feeder in January or February, but it’s also a little bit scary. Our environment is changing.”

As a result, what you learned about birds just a few years ago might be outdated. As the climate and habitat are altered, birds are demonstrating a wonderful capacity to adapt to their ever-changing surroundings.

Noticeable shift

“Over a period of the past couple decades, the ranges of some of our favorite birds are changing, and some are shrinking,” said Craig Thompson, executive director at Five Rivers Environmental Education Center in Delmar and vice chairman of the Audubon Council of New York State. “I’ve noticed some changes myself, and while it could be because of landscape changes and to some extent people feeding birds, it’s clear that migration patterns are being altered and that the birds are capable of adapting. We’re seeing birds in the Capital Region that we didn’t always see that much, and there are others that we used to see quite a bit that we don’t see that much of anymore.”

For example, the red-bellied woodpecker, not a regular visitor to the Capital Region 20 years ago, now seem to be popping up at feeders throughout the area. The evening grosbeak, meanwhile, which could be seen in flocks two decades ago, now seems much more scarce.

“Evening grosbeaks came in like a tide a while ago, but then they retreated and seemed to have moved back west and up into the Adirondacks,” said Guthrie, who lives in New Baltimore, south of Albany. “They seem to have vagabond ways. So there is something going on with their distribution system. But we don’t have all the answers. Bird populations seem to ebb and flow, and sometimes you can’t pinpoint why.”

Easier winter

While many birds still migrate, particularly the insect eaters, those that survive on fruits and seeds will often end up sticking around throughout the winter.

“The fruit and seed eaters are a little less regimented than the insect eaters,” said Jeremy Kirchman, an ornithologist with the New York State Museum. “They seem highly adaptive to the seasonal movements, and a lot of those birds can make it through the winter because the food source is constant throughout the year.”

While global warming, and as a result warmer winters, is making it easier for the birds who winter in the Northeast, it’s also affecting the migratory group.

“There is good evidence that has been published suggesting that migratory birds are heading back north earlier than usual,” said Kirchman. “Their arrival dates are being monitored, and depending upon where you are, some birds are coming back six days earlier and some as much as 12 days earlier. It may not sound like a whole lot over a short time, but it’s very interesting. That’s statistical evidence that tells us the world is changing.”

The early arrivals and the shifting nesting and migration patterns mean just one thing to Guthrie.

“The birds are retreating north just like the glaciers retreated,” he said. “As the global climate changes, the birds adapt. Some species aren’t flying as far south as they used to, and some are nesting further north than they used to. The cardinal was pretty much a southern bird when I was a kid, and in my own birding experience I’ve noticed that change. Now, you see them all the time, regardless of what month it is.”

Dangerous flying

While the migratory habits of birds may be changing, one thing remains a constant. Flying at night — most birds are nocturnal migrators — is dangerous.

“Most of our songbirds are subject to the hazards of nocturnal migration,” said Kirchman, “and as a result they have a hard time avoiding large stationary structures. The Corning Tower here in Albany kills a lot of birds every fall and spring, and in Manhattan it happens all the time.”

Another issue for birds heading north or south is the changing landscape.

“Migration takes a toll on the bird population in many ways,” said Guthrie. “A lot of these birds migrate along the coast as they head south or they fly out over the ocean, and when they come back to land instead of seeing a beach, grass or a cedar forest, they run into a high-rise condo or asphalt. There ends up being very little cover for things like kinglets, and they end up getting taken by marauding hawks and gulls, or even foxes and cats. They’re finding their resting places along the way are changing.”

Some species benefiting

In rare cases, the changing habitat can be a real boon to some species.

“Centuries ago, they say a squirrel could have gone from Mississippi to Maine without touching the ground because of the huge forests,” said Guthrie. “That wasn’t suitable for Canada geese — so they stayed in the tundra or the prairie states. Well, we come in and clear the forests and put up little ponds, and the geese really liked it here. As a result, they settled down here and now have no reason to leave. They might head south a little in the winter but only to where there’s open water.”

Keeping abreast of the changing bird scene may require a little extra work, but for birders such as Thompson it’s time well spent.

“I think it’s fascinating to see how the ranges of a lot of birds have expanded or just changed in the last 20 years,” said Thompson. “I came from the Buffalo area, and I never saw a tufted titmouse until I went to college in New York City. Now, they’re all over the place, and to me it’s wonderful to see the red-bellied woodpecker. People are suddenly seeing the darn thing all over the place, and probably 15 years ago you never saw one around here.”