Just how reliant on bird feeders are birds?

That’s a perennial question we get, but we most often receive it in the fall as (human) summer residents go south for our winter (aka “snowbirds”). The concern is that birds have become dependent on the food source, so what will happen when the homeowners stop feeding them?

It was fun to get this question in the spring from the self-proclaimed “reverse migrants,” Mike Morrison and Judy Steadman, who are about to leave Maine for the summer. They asked, “We are wondering about the effect on the birds by taking in our several bird feeders … Is it better to take them in one at a time or take them in all at once (cold turkey as it were – sorry!)?”

Here’s how I like to oversimplify what bird feeders do: They are a tool for making birds easier for us to see. Putting more food out in the environment will help birds, but it is just another source in their diverse “basket” of offerings. The seeds we put out are an easy and generally abundant food source, but birds have spent more than 65 million years evolving to find food during times of both abundance and drought, so it makes sense that a few decades of artificially feeding birds won’t have a drastic impact on their behavior.

Mike and Judy’s follow-up question, regarding if it was better to take the feeders down one at a time, or if it was OK to cut them of – go cold turkey! With the aforementioned lack of dependence in mind, I don’t think there is any need to put extra effort into gradually taking feeders down. If you think about the dramatic shifts that happen in nature, like a storm wiping out a food source or a cold-snap freezing over a body of water, you’ll realize birds are no strangers to dramatic fluctuations.

Whatever small amount of help that feeders are providing, they are going to be most helpful in the winter when food is scarce. Heading into the spring, food is becoming more and more abundant by the day, and you’ll see birds coming to feeders even less. This is an important reminder that when birds are nesting, they are reliant on native plants that will support native insects, especially lepidoptera larvae (butterfly and moth caterpillars), which they are feeding to their babies. The next generation of baby birds can’t be raised on bird seeds.

A research paper, published in 2021 by scientists at Oregon State University, looked at “how energetic challenges lead to behavioral changes in feeder use during winter.” In the study, chickadees were artificially handicapped by clipping some of their flight feathers, and tracked with radio frequency identity chips to measure how frequently they visited feeders. Interestingly, the researchers found that the chickadees actually reduced their visits to feeders, presumably avoiding the risk of exposure to predators, and also demonstrated that natural foods (like seeds, berries and insects) were abundant enough for them. Jim Rivers, one of the authors of the paper, said “It’s clear that the chickadees in our study did not increase their visitation rates nor did they increase their reliance on supplemental feed during a period when they might have benefited from it the most.”

BIG NIGHT IS COMING

One of the most anticipated events in early April for naturalists is the amphibian migration known as “big night.”

The big night typically happens on the first warm and rainy night of the spring (45 degrees or warmer) when the majority of amphibians – frogs and salamanders – emerge from the burrows where they overwintered and journey back to the vernal pools they were born in, to breed. (A vernal pool is a small temporary wetland which fills with water in spring or fall.) Depending on your area, conditions for the big night may not occur for another week or more, but it is a good idea to be prepared because we often don’t know if the weather conditions will be ideal until right before it happens.

The journey may not seem very long on a geographic scale, until you consider that these cold-blooded animals may be just a few inches long. Their migrations are made even more difficult since roads transect so many of the routes the animals have to follow. Slow-moving terrestrial animals crossing roads on nights with poor visibility unfortunately leads to high rates of mortality. Maine Big Night, a community science project that was started to collect data on these frog and salamander movements, reported 29.4% of the 8,558 amphibians detected during the 2022 surveys – across 243 sites with 1,331 hours of effort – were found dead.

Maine Big Night is still recruiting volunteers to go out on warm rainy nights to conduct surveys and help amphibians cross safely. You can learn more about the project at vernalpools.me/big-night. You can adopt one of the identified survey sites and collect data through May 15. Maine Audubon and other organizations lend out kits with all the gear you might need (like headlamps and safety vests). Maine Big Night also has a very active Facebook page where you can learn more and stay up to date on timing of the big night: facebook.com/groups/bignightmaine.

Whether it is becoming a volunteer, or just driving more carefully and being mindful of amphibians in the spring, any additional help can go a long way toward helping these threatened animals.

Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit 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, 7 to 9 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.

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