Robins tend to molt feathers in the fall, giving them a less colorful appearance and also a new set of feathers to aid in migration or even just help them survive. Carolyn Kaster/Associated Press
The coloration of our birds is always a fun topic to write about. I recently wrote about an interesting molt that house sparrows have in Maine Audubon’s “Backyard Bird of the Month” feature on our website, so it was interesting to get a question recently from Duncan Barnes that ties in nicely. Duncan asked: “We have four or five robins … in Kennebunkport with very pale orange breast feathers as opposed to the normal distinctive orange. The gray feathers on these birds are also paler than normal. Is this a genetic color phase or the sign of something else?”
To answer this, let’s take a look at what birds are doing right now and how their plumage ties in. Most birds would have molted their feathers in late winter or early spring, so that they’d have their “breeding plumage” (also called alternate plumage) and be ready to find a mate. After migrating and arriving on their breeding grounds, they’ll sing and display, doing whatever it takes to get that mate. Then all the focus is on caring for eggs and chicks, until the young have fledged and are on their own. Finally, those adult birds can think about themselves for a minute, and typically they’ll molt again. This fall molt into a “non-breeding plumage” (also called basic plumage) will give them a less colorful appearance and also a new set of feathers to aid in migration or even just help them survive. Feathers, like your favorite flannel, wear out over time, and no matter how comfy it is, there comes a time that it must be replaced.
Replacing feathers takes a lot of energy, which is why most birds won’t do it while they are also doing very laborious tasks like migrating or raising young. Some species save energy by not going through this twice-annual molt and instead will only molt once, like the aforementioned house sparrow, and even our American robins. These two both skip the spring “pre-alternate molt” and only have one molt in the fall. The new feathers that grow in will typically have pale tips on the ends of them, which gets us to Duncan’s pale-looking robins. Those pale tips have less melanin in them, in the case of the back feathers (and less carotenoids on the breast), which means they aren’t as strong and will wear away over time.
Throughout the winter those pale tips will wear away and by next spring, when the robins are looking for a mate, they’ll be showing off the darker back and brighter red chest that had otherwise been concealed most of the winter. That drab appearance is likely to help lower the chances of being detected by a predator, and they’ve saved a ton of energy by not having to molt in the spring. A great adaptation for these busy birds!
OUTDOOR LIGHTING
The way we light the outdoors can be detrimental to wildlife and often it just takes a few simple changes to drastically reduce the effects we are having. Peg Cushman recently wrote in asking for advice on changes that could be made to the outdoor fixtures at her condo association, so I wanted to share some of the key things to think about here.
First, think about where you need outdoor lighting. Cutting down on the amount of light you’re putting along a landscape can make a big difference, especially if you can focus the light just on the areas you need it. Lighting a path is a classic example. Instead of having one massive light pointed all around the path, can you use smaller lights that just cast light down on the walking path? The direction is key: use lights that will cut off the light emitted so that it is only pointed down. Light that is pointing up usually isn’t illuminating anything helpful and is going to disorient birds and insects.
Next, only use outdoor lighting when you need it. Driving around, I’m amazed by how many people blast bright lights on their house all night. This is a spooky time of the year, but please remember that vampires are not real, so those lights aren’t protecting you. Only turning outdoors lights on when you are actually outdoors doesn’t sound profound, but I bet if everyone was more mindful of this then collectively we’d have a big impact. Using products like timers, to automatically shut off lights at a certain time, or motion sensors that only turn the lights on when there is someone (or something) crosses their path, are simple ways to cut down on usage and reduce impacts to wildlife.
There is plenty more to consider, including the type of lighting fixture you use, how much lighting you need (dimmable lights are a great option), and more. I recommend checking out some of the great resources available from the International Dark-Sky Association (darksky.org). There, you can learn more about the effects of different colors and types of lights and get a list of recommended light fixtures that will make your yard (or housing association) wildlife friendly.
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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