The current outbreak of avian influenza — the bird flu — has been making a lot of headlines lately, as detections increase and egg prices rise, so it feels important to acknowledge the timeline and effects of the disease. As a reminder, it has been several years since the first detection in the state: a non-commercial backyard flock of chickens in March 2022. We’ve seen increased cases in commercial poultry across the country and the unfortunate culls as a result. With time, there have been more cases detected in wild birds, too, so let’s look at which groups of wild birds are being affected and what precautions should be taken on that front.

Gulls (seagulls) are one group that we know is being hit hard locally. We observed this directly during the first summer of 2022 when hundreds of dead gulls were found along the shores of islands on which they had been nesting.

These nesting colonies, where birds are in close proximity to each other, are where they are going to be most at risk of spreading influenza. While we don’t know exactly how many of these nesting birds were affected, we are starting to see the impact show up in other surveys. The Christmas Bird Count is the longest running citizen science project, over 100 years old now, where observers count (to the best of their abilities) all of the birds within a predetermined 15-mile diameter circle.

This is repeated every year and we can identify trends in bird populations. While we typically don’t focus too much on a single year, because many factors can influence results, especially weather, a family like gulls should not see too much variation based on those factors. All that being said, the Greater Portland Christmas Bird Count in mid-December saw the lowest total of both American herring gulls and great black-backed gulls in the history of the count: 1,055 American herring gulls and 78 great black-backed gulls, way down from record highs of 12,773 and 893. For context, the only other species that saw a “new low” during the count was common mergansers, which was more likely due to the cold weather and lack of open fresh water. Seven species saw “new highs” in 2024.

As a reminder that this is also a global disease, Great Skuas haven’t been detected in the Gulf of Maine since avian flu hit their colonies in 2021. It’s being reported that the UK nesting colonies lost millions of birds to avian influenza, with 76% of the population killed. The Great Skua is a rare seabird anywhere on the west side of the Atlantic, but one that reliably ventured into the Gulf of Maine after its breeding season. This has been the primary target of our annual “pelagic” boat trip out of Bar Harbor each September, and time will tell if the population rebounds enough to become a sight in Maine waters again.

It’s worth keeping in mind that wild birds are killed by many other things, especially things caused or influenced by humans, both directly and indirectly. Studies show more than 2 billion birds per year in the United States are killed by outdoor cats (about 30% of those from owned cats) and 599 million birds are killed colliding with windows. I mention this not to downplay the threat of avian influenza at all, but to remind readers of the unfortunately very common sources of mortality in birds. I’m in a number of bird-focused Facebook groups (honestly, it’s embarrassing how many!), and I’m noticing that many obvious window-strikes or predator kills are being blamed on avian influenza (not by professionals, just by the armchair experts on Facebook). Yes, we need to use caution around a dead bird that may be carrying avian influenza. But we also need to keep cats indoors and fix the windows that birds collide with. For more information on making windows safe for birds, see our BirdSafe Maine project (www.birdsafemaine.org).

Remember that avian influenza spreads via feces, saliva and mucus, which is why it spreads faster among birds in very close quarters (especially poultry in this country, hence the need for flock owners to take protective measures). Ducks and geese make up most of the cases in wild birds, but we are also seeing it show up in some of the predators or species that feed on the carcasses of sick birds, like hawks, eagles, crows and vultures. What we consider the “backyard birds,” like chickadees and woodpeckers, are very unlikely to contract avian influenza, so there is no need to stop feeding those birds or take down bird feeders. You should always keep your feeders clean, but this is a good time to be extra vigilant with regular cleanings and also protect yourself from exposure. Avoid contact with a sick or dead wild bird. If you do have a report of a sick or dead wild bird, call Maine Inland Fisheries and Wildlife at 207-287-8000 or 800-452-4664, or report it online. (More info: mefishwildlife.com)

Think about the things you can do to help birds around your yard, be it during an avian influenza outbreak or not. Keeping your cats indoors is the best thing you can do, then treat your windows to break up reflections and reduce strikes. Support the next generation of birds with native plants: bird seed helps us see wild birds, while native plants sustain them.

Ask Maine Audubon is a bi-monthly column by Maine Audubon Staff Naturalist Doug Hitchcox. Have you got a nature question of your own? 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, 8-10 a.m., at Maine Audubon’s Gilsland Farm Audubon Center in Falmouth.