Why are there so few birds at your feeder? One reason is because on an abundance of acorns and pine cones, which are a better food source. Carl D. Walsh/Staff Photographer
This has been an entertaining fall for us at Maine Audubon, as we field inquiries ranging from “Where are the birds!?” to “Why is this bird still here?” We’ve tackled these questions here before, and want to again recognize that a single person’s observations within a limited area is biased. But as we head into December it is worth addressing some of these concerns and questions again, especially with more and new information available – because that is how science works.
First, an update on the most popular question of the fall: Where are the birds? To quickly recap: this fall has been exceptional for mast, which we’ll generalize as the “fruit of the forest.” I hope everyone has decided to “leave the leaves” on the ground, but I’m sure if you raked your lawn you noticed the abundance of acorns and pine cones this year. Mast years (the mass production of seeds and fruits) can occur for a variety of reasons; this year it was likely due to the very wet summer we had. With so much natural food on the landscape, birds, and even squirrels – yes, people have actually been concerned about the lack of squirrels around their houses – don’t need to come to feeders for the food we put out for them because nature has provided lots of better quality (higher nutritional value) food.
We’ve also had a number of very warm days this fall, allowing insects to stay active later. Insects are the best protein source that most birds are going to have until spring. I like using the analogy that birds are viewing food on the landscape right now the same way we see seasonal restaurants about to close; I’ll prioritize a trip to Big Daddy’s for coconut Oreo ice cream before it disappears until next year (which at the time of this writing is sadly the case).
As expected, as the temperature has dropped and snow has covered some natural food, it has been a relief to see “they’re back!” posts on various bird and wildlife Facebook groups. The change won’t take place overnight though, so give your local birds time to adjust. It’s similar to when you put out a bird feeder for the first time; birds need time to find that food and change their routines to start visiting more regularly. Remember, we are only supplementing their diet with the food we put out, they are not becoming reliant on our feeders. And despite the snow and cold temperatures, there is still a lot of natural food available.
Winterberries are ripening and soon to be picked over, which is a good plug for leaving them on the landscape – let’s be honest, they look better in a wetland with robins and waxwings feeding on them than snipped and woven into a wreath on your porch. Many birds would have taken advantage of the abundance of food over the past months to store it for easy access now. I’ve especially enjoyed spotting blue jays flying around carrying acorns in their beaks, then caching them in tree cavities for later consumption. Chickadees are being studied for their remarkable ability to grow their hippocampus (the memory center of the brain) in the winter so they can better recall where they have cached seeds. So don’t worry if “your” birds have returned yet. If anything, the lack of their activity at feeders means that they are doing better elsewhere.
Now to address the opposite question: Why are the birds still here? Many of the factors mentioned above also explain why some birds are lingering later than usual this year. There is a common misconception that most birds are going to be at risk of dying due to the weather, but actually the bigger threat is from food availability. This concern always comes up when some summer residents stay later than usual and people are concerned that the cold weather will kill them. Yes, there are going to be a few sad cases like the famous great black hawk that tried overwintering in Portland five years ago, but for the vast majority of migrants, especially those who have evolved around temperate regions, they have adapted to be able to handle harsher conditions than most people give them credit for.
I highly recommend reading Bernd Heinrich’s “Winter World” if you want an intimate look at wildlife’s amazing ability to survive Maine winters, especially the tiny golden-crowned kinglet. Speaking of kinglets, while golden-crowned kinglets overwinter in Maine, their cousins, the ruby-crowned kinglets, typically all migrate south. This fall we are seeing a noticeable increase in the number of ruby-crowned kinglets reported. In the last week of November they were on 1.5% of checklists reported to eBird (Cornell’s database of bird sightings) in Maine, versus about 0.5% that we usually see during that time.
Great egrets have also been lingering late this year, with an especially visible one hanging around Back Cove in Portland and generating a lot of interest. For insect-eating kinglets and fish-eating egrets, there is going to be a risk/reward playing out each day for them as long as food is still available. Those that can overwinter farther north, and closer to their breeding grounds, are probably going to get better territories and be more productive next summer, as long as they make it through the winter.
With an increasingly volatile climate, we expect to see changes in plants and wildlife with the seasons. I do want to make a plug for people to get involved with various contributory science projects to help collect data on large scales so this can be studied. I mention eBird (ebird.org) often, but if birds aren’t your thing then iNaturalist (inaturalist.org) is a great spot to submit observations about everything from the winter moths on your porch in December to the funky mushroom on your woodpile. Remember, unless someone like you cares a whole awful lot, nothing is going to get better. It’s not.
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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