One of the highlights of winter bird watching is participating in the annual Christmas Bird Count. This is the longest running contributory science project in the country, now in its 124th year since being started by National Audubon.

While it will still take a few weeks to get all the data in, then maybe months to process it all, I wanted to share a few sightings from the three counts that I helped with this year and see how they compare to what you might be seeing around the state.

Before diving into results, a quick reminder is that the Christmas Bird Count (CBC) is done by having groups of observers go out on a single day and attempt to count all the birds within a 15-mile diameter. These large circles are typically divided up into sections, and each of those sections will have a team of birders covering the ground by foot and car (and sometimes boat) to tally each species and the number of individuals they can find.

One comment we hear often is from people who assert that “there is no way you are counting all the birds,” and we do know it is impossible to find them all and keep track of each individual. So a core principle of the CBC is that you do it the exact same way each year, because as long as you “do it wrong” every year, you’ll still identify the trends. The CBC is one of the best surveys for showing us changes in bird populations in the United States and Canada. Another important thing to know is that the “count period” runs from Dec. 14 through Jan. 5, so that many counts can be done without all falling on the same day. Most years, Maine has around 30 counts around the state.

The first count I helped with this year was the Greater Portland CBC on Dec. 16. This count typically produces the largest number of species in Maine, aided by being early in the count period, having a fairly southern and coastal location, and because a large number of volunteers help.

This day was relatively warm, in the mid-40s, which is important to acknowledge because there are sometimes large temperature fluctuations between counts from year to year. Again, the trends reveal themselves by looking at the long-term data.

Keep the analogy of weather versus climate in mind, too. With warm weather, we often see that species on the northern cusp of their wintering range are able to linger here in larger numbers than when they are pushed south by the cold. This was best represented by the species with new high counts (defined as the highest number of individuals of that species compared to past years of that CBC) including: three marsh wrens, seven swamp sparrows, seven yellow-bellied sapsuckers, 16 great blue herons, nine gadwall, and 268 white-throated sparrows. Most of those use a habitat that typically freezes over by mid-December, so it is obvious why there are more here when it is still warm.

Another species seen more often than usual was the Carolina wren at 65 individuals, crushing the previous high of 39. This is a species that has been rapidly expanding its range because of climate change, and it’s amazing to see its spread through Maine. Eastern bluebirds have also seen a huge spike in their overwintering population, but for the Greater Portland CBC, there were 133 reported, falling short of a previous high of 210.

The next count I helped with was the York CBC, which was postponed a day, to Dec. 19, because of the massive storm that passed through the state and its resulting floods and tree damage. For that count, I usually do a sea watch from the Nubble Lighthouse in York, counting seabirds as they are moving offshore. It was almost funny to be there hoping for a dovekie, the small relative of a puffin, while dozens were being reported all over the state, tossed inland from the storm.

There were a couple of species on the York CBC that had new high counts as a result of the storm, including Northern gannets (250) and black scoters (1,408). The scoters were seen in large numbers sheltering in coves from the persisting surf, and the gannets were in large feeding flocks offshore, typically farther out than we can see but certainly pushed in by the easterly breeze. Other species with high counts were several blackbirds, and as you could have guessed, Carolina wren with 46 individuals, besting the previous count high of 28.

The final count I did was the Monhegan CBC, a count that I took over from a compiler in 2011. It is always a challenge to run this count, as the ferry to Monhegan only runs a few times each week during the winter, and finding volunteers who can make the multi-day commitment around the holidays is tough. Many thanks to Mael and Jeff for spending what turned out to be a windy and rainy day on Dec. 28, helping census the birds on the island.

Despite the weather, we managed to track down 49 species, our highest total since 2012. Most of the species counts were low, but highlights included a female gadwall mixed in with mallards, only the second record (ever) for that species on the heavily birded island. A marsh wren and two palm warblers were new for the Monhegan CBC, also late lingering species that were not unexpected given what we’d been seeing around the state.

The one scary thing pouring through the counts, despite the increase in diversity, is the decrease in abundance. For comparison, the total count of individuals on the Monhegan CBC in the 1980s was roughly 1,500 to 2,300 birds, while over the past decade, we’re lucky to break 500. These declines are well documented, and I recommend visiting 3billionbirds.org to look at the research that has come out of projects like the CBC and breeding bird surveys to document the loss of “one in four birds since 1970.”

Let us know in the comments for this column if this is similar to what you’ve been seeing lately. Seeing any Carolina wrens or high numbers of white-throated sparrows around you?

Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit www.maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug and other naturalists lead free bird walks on Thursday mornings, 8 to 10 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.

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