In late fall, Shelley Martin was looking out a window of her home in Warren when she spied an unusual, ghostly songbird. Perched in the evergreen trees not far from her birdfeeder, the small bird was bright white. She’d never seen anything like it.
Based on the bird’s size and shape, she initially thought it was an albino black-capped chickadee. Albinism is a rare condition in which an animal cannot produce the pigment melanin, so it’s entirely white. Shortening the term, Martin named the bird “Biny.”
Every day, she watched for it. And Biny kept showing up. Now, in mid-February, the rare bird is still a daily visitor.
“He comes and goes with the chickadees and the nuthatches about once a day,” Martin said. “Usually it’s first thing in the morning.”
Curious about the bird’s appearance, Martin did some research into albinism and came across another term: leucism.
Leucism is an umbrella term that describes a number of plumage irregularities that can cause white feathers. There’s some disagreement about whether the condition is genetic or caused by cells that were damaged during development, but it often doesn’t affect the entire bird. Instead, the white feathers often appear in patches.
“They call it piebald, where it’s really patches of white,” said Adrienne Leppold, a wildlife biologist with the Maine Department of Inland Fisheries and Wildlife. “You can also have a bird with an all white head and the rest of the body a normal color. I’ve seen pictures of blue jays like that.”
Albinism, on the other hand, is a genetic mutation that causes the absence of tyrosinase in pigment cells, which makes it impossible for those cells to produce melanin pigments. Because of this, the most distinctive feature of albinism is red or pink eyes.
“With albinism, there’s no pigment in any of the body systems at all,” said Leppold. “So then there’s actually no color in the eyes. All that’s reflected is the red of the blood vessels.”
Based on that information, Martin believes her white bird, Biny, is leucistic. The bird’s eyes appear to be dark brown or black — not pink or red. Furthermore, the bird does have some black and gray tail feathers and some faint patches of dark coloration under its snowy plumage.
Both Leppold and BDN columnist and bird expert Bob Duchesne agree with Martin that the bird is likely a black-capped chickadee, based on photographs, but they need a better view of the beak shape to be certain. Other birders on the MAINE Birds Facebook page believe it’s a dark-eyed junco. Both songbirds are similar in shape and size and are common in Maine.
Over the past few years, Maine residents have shared photos of what appears to be a leucistic bluejay, cardinal, song sparrow, American goldfinch and downy woodpecker on the MAINE Birds Facebook page.
“We see a lot more reports [of leucism] in feeder birds because those are the birds that are most regularly being observed by us, but it can occur in all species of birds,” Leppold said. “I’ve seen pictures of ostriches and things in Africa that have leucistic patterns.”
The color of bird feathers come from several sources — not just melanin. Therefore, albino and leucistic birds may display certain colors. Carotenoids and porphyrins are the two other types of pigments that are responsible for colors in bird feathers. In addition, the structure of feathers can cause different colors to show, Leppold said.
“A lot of the blues and greens and iridescence we see on hummingbirds, grackles, even crows, comes from the actual structure of feathers … microscopic pieces that can reflect light in different ways or block light,” Leppold said.
True albinos are thought to be rare in the wild, according to an article by the British Trust for Ornithology. Leucistic animals are more common. But both conditions often make the bird more vulnerable to predators and other dangers.
“It’s often a weakness,” Leppold said. “Not only does it make them more visible to predators, but white feathers that are lacking pigment cells are just weaker in general. They’re more subject to degradation. They can break down and start compromising flight and thermal regulation or both.”
Martin has noticed that her white bird, Biny, usually doesn’t visit the birdfeeder. Instead, the bird perches in a nearby cluster of evergreen trees. And when other birds drop seeds nearby, Biny snatches them up.
Worried that Biny wasn’t getting a fair share of the seeds, Martin purchased some quality bird food of nuts and berries to spread underneath the trees where the bird usually perches.
“I go out and say, ‘Come on, Biny. Come get your breakfast!’” she said. “It’s become an obsession. I was worried, but I think he’ll make it through the winter.”