The populations and species of birds who inhabit the Passamaquoddy Bay region have been changing steadily -- and occasionally dramatically -- over the past half century, with climate change and human affected displacement being the primary causes. While some newcomers are finding the conditions favorable, others are poised to disappear from the region entirely.
      Generally speaking, "There are fewer birds now in terms of numbers," says Jim Wilson of Saint John, a birder for the past 60 years and a 2019 recipient of the Order of New Brunswick for his work as a naturalist. "Everyone feels the same way. When you look back at the notes -- that's where you see the differences," Wilson says, referencing how records gathered over the years show a "general, ominous decline in bird numbers."
      That trend isn't across the board, however. Among the biggest success stories is the turkey vulture, which was virtually unknown in the area in 1970s, Wilson recalls. By the 1990s, it started appearing in the southern part of the province. In the winter of 2010, he saw his first one in Saint John.
      "They're eking out an existence, living in the winter -- without a hat! They've got a naked head," Wilson says. He recalls seeing one when it was 30 degrees Celsius sitting on top of an unused chimney. "It would lean forward to put its head over the chimney to get enough warm air for itself" to stay warm. "They're a very resilient species."
      Another species that's relatively new to the area is the northern cardinal, Wilson says, recounting that there were effectively none in the 1970s but now he can hear five or six males singing in the course of a single morning's run. "We have a lot of cardinals."
      Not all of the newcomers have arrived due to climate change, Wilson says. In the case of cardinals, for instance, their spread has been aided by the rising popularity of bird feeders. Wild turkeys, on the other hand, have spread upward from southern Maine after being released there in the 1970s. And then there are Canada geese, whose proliferation across the province and parts of Maine can be attributed to New Brunswick importing 4,000 geese from Ontario in the 1990s.
      "Now practically all the wetlands have nesting pairs of Canada geese," Wilson says, adding that the "big, aggressive" geese make poor neighbors and pose a problem for black ducks, mallards, wood ducks and teal.

Impacts on local species
      Some native species have done well with the warming weather, including American crows, Wilson says. "When we first moved here [in the 1970s], most crows left in the winter," he says, noting that he would count around three dozen crows in the winter of 1972. Now, there are between 600 to 1,000 each year. "It's incredible, the number of crows. And they don't leave in the winter."
      Boreal chickadees are another story. Once found "across New Brunswick," including in Wilson's backyard in the 1970s, they're now "very difficult to find except in the north." It's somewhat unclear why they're diminishing, although some attribute it to the more intensive logging practices that are removing tracts of coniferous woodland. However, Wilson points out, the boreal chickadee has also seemingly vanished from White Head Island, an island off Grand Manan that was the southern bastion of the species. No logging has taken place on the island, meaning "it's got to be climate change directly," Wilson says, with possible changes to the quality of its food sources in play. "I haven't seen a boreal this year."
      The Canada jay, like the boreal chickadee, prefers extensive tracks of coniferous forest and cool temperatures, and it has similarly declined. "Those two species are fading away quietly," Wilson says.
      As a group, aerial insectivores -- including swallows, purple martins, flycatchers and whippoorwills -- "have all gone down precipitously in numbers," Wilson says, with some species having lost as much as 90% of their numbers in the past few decades as a result of a declining insect populations partly caused by climate change.
      Apart from population changes, naturalists are noting changes in the morphologies of some species, such as the dark eyed junco. Citing a recent study, Audubon staff naturalist Doug Hitchcox summarizes, "The trend that was found is that some species, like the junco, appear to be developing larger bills over time, which is helpful in body temperature regulation."
      Researchers at the University of New Brunswick who have been studying the puffins of Machias Seal Island have documented similar changes in the increasing bill size of puffins -- as well as a notable decrease in the size of chicks since the 1990s.
      Over the past few decades, puffins have been struggling to find adequate supplies of herring and other small fish, causing the population to diminish. "Puffins only survive in the north Atlantic's cold waters, where the fish they've evolved over millions of years to eat are found," Hitchcox says. "So the warm waters and fish associated with them are going to force puffins out of the Gulf of Maine faster than they would be able to adapt."
      There are some "bright spots," Wilson shares, pointing to the success stories of eagles, ospreys and peregrine falcons -- all of which have "come back from the brink" -- as evidence that humans can implement effectively policies to restore species.

Keeping track of changes
      Local residents can expect to see ongoing changes to the bird species and populations around Passamaquoddy Bay, Hitchcox says, with encroaching breeding pairs of fish crows, black vultures, red bellied woodpeckers and soon boat tailed grackles. People can also expect to see occasional vagrants, such as the stellar sea eagle that surprised birders in 2022, and the odd black billed cuckoo. And while birds have a history of vagrancy, sometimes it's because they're looking for new breeding grounds or due to new pathways being opened.
      As an example, a tufted puffin has been reported in the Gulf of Maine in recent years. Traditionally a Pacific species, it could only have gotten to the area due to the slow opening of the Northwest Passage, Hitchcox says.
      While it can sometimes be challenging to assess how established bird populations are being affected by climate change and new arrivals over time, Wilson asserts that the best available tool is data -- and he stresses the importance of public submissions to resources such as Cornell University's eBird. "A lot of these things are subtle. They change over time. You may not realize the difference until you look at the numbers."
      Apart from making sighting records on eBird -- available at ebird.org -- those interested can access the recently released preliminary results from the second five year Maine bird count, with counts taken between 2018 and 2022, at www.maine.gov/ifw/fish wildlife/maine bird atlas. According to the five year count, Maine has 33 new species in the state compared to the first five year count taken between 1978 and 1983.