Spring snuck up on me this year, probably because I kept shoveling it out of my driveway for so long. There were 2 feet of snow on the ground as the first vulture passed over. Ice fishermen were in front of my house when the first blackbirds showed up.

Thursday night, April 2, was mild with a southerly flow of air and a nearly full moon — a perfect migration night. Eastern phoebes, northern flickers, red-shouldered hawks, sharp-shinned hawks and tree swallows arrived the next day. I was particularly taken aback by the tree swallow. I heard its twittering approach, but my view was blocked by a 6-foot snowbank on the plowed edge of the parking lot.

Birds know when it is time to migrate. They take their cues from the length of day. They wait for favorable winds, then off they go. Migrants are aware of the southern conditions when they depart, but they don’t know the northern conditions that await them. The birds heading toward Maine right now have no idea what kind of winter we’ve just had. Boy, are they in for a surprise.

American woodcocks were among the first to be surprised. They customarily return in mid-March, when some of the snowpack has receded. Woodcocks are well camouflaged and are virtually invisible against a background of leaf litter. It’s not uncommon for them to find patches of snow on the ground when they return, but seldom do they return to a landscape so completely covered. A brown bird on white snow may as well hold up a sign that says “eat me.” They’ve had to make do with hiding in what scarce brown patches they could find. They were slow to begin calling, waiting a week or two.

Despite the long winter and lingering snow, birds are arriving right on time. Most should have little trouble. Waterfowl have been collecting in open waters, especially below dams and in salt marshes. Early-arriving sharp-shinned hawks prey on birds, and there are still plenty of wintering finches around to sustain them.

Seed-eaters are doing fine. The winter finch invasion was not huge, and there is plenty of food around. Fruit-eaters were late getting to Maine this winter, so there are ample berries and crab apples still available. They’re doing fine. Woodpeckers are not suffering. The pileated woodpeckers are demolishing trees and making lots of courtship noise. Hairy and downy woodpeckers are pairing up.

However, insect-eaters may regret arriving on time. Tree swallows usually return around Easter, and eastern phoebes typically appear about a week before the Kenduskeag Stream Canoe Race. Both species already have returned, and they are likely to be conserving energy until things warm up. Phoebes normally would be loud by now, but they’ve remained quiet, longer than usual.

Ospreys have been slow to return, but only by a few days. Song sparrows are returning, but the snow has dissuaded them from singing in northern Maine. I normally expect to hear the first song around April Fool’s Day. Robins also have resisted the urge to sing, even as their numbers have built over the last week.

In short, the birds have adjusted to the late winter. Breeding strategy is part of the balance of nature. Early birds risk hostile conditions upon arrival. But in a good year, they grab the best nesting spots and outcompete laggards. Late birds avoid bad weather but lose out on good nesting sites and available mates. It all evens out. When early birds arrive too early, they try to hunker down and conserve energy.

Then there are the truly extraordinary birds — birds that arrive accidentally. The Maine birding world is abuzz with the news of a surfbird in Biddeford Pool. This medium-sized shorebird is confined to the Pacific coast. It breeds inland along Alaskan slopes and tundra, then winters along the ocean edge all the way to the southern tip of Chile. But it hates to cross land and rarely wanders East. In fact, the only other recorded occurrence of a surfbird along the entire Atlantic Coast happened in New Smyrna Beach, Florida, in 2005. A surfbird in Maine boggles the mind.

The surfbird has been keeping company with ruddy turnstones and purple sandpipers. Naturally, I scooted down to Biddeford Pool this past weekend in an effort to find it. I failed. Luck, like weather, averages out. I’ve had good luck this winter. Bad luck was overdue. Or, to put it positively, I succeeded at failure.

Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. Bob developed the Maine Birding Trail, with information at mainebirdingtrail.com. Bob can be reached at duchesne@midmaine.com.