Why this super-rare Lower Mainland crow has white feathers and a black beak

May 24 2023, 6:08 pm

A rare crow with a striking combination of white feathers and a black beak was spotted in a Fraser Valley park this week, and a wildlife expert says the chances of seeing it are about one in 10,000.

Potographer Bill Peremiczky noticed the unusual crow near the pond in Sardis Park last week.¬†He told Daily Hive he’d never seen anything like it, saying it must be one of a kind.

As it turns out, white crows do sometimes appear in nature, but they’re very rare, according to John Marzluff, a professor of wildlife science at the University of Washington.

This crow was leucistic, meaning it carries a genetic mutation that prevents pigment from being deposited in the feathers. It’s similar to albinism, but albino birds wouldn’t have melanin anywhere — their eyes, skin, and mouth lining would are pink as well.

Marzluff said the crow from Chilliwack is typical for a leucistic crow — uniform white plumage that could be brown or reddish in places. Leucism can sometimes affect patches of a bird’s feathers, which can be genetic or due to damage to a feather follicle.

Marzluff said one or two leucistic crows are typically spotted every year in the Seattle area, and based on the crow population of 15,000 to 30,000 birds, he estimates the incidents of leucism is about one in every 10,000 crows. But of course, it’s impossible to know precisely.

Leucism can impact a bird’s fistness, Marzluff added. The lack of pigmentation makes feathers weaker, and would likely be pronounced in a dark bird such as a crow. White feathers break off more easily, and would wear out quicker with sun exposure.

“They’re weaker feathers, and that could affect the bird’s ability to fly,” Marzluff said.

Leucism could also potentially affect the bird’s social relations. Marzluff has experience studying a leucistic raven, a bird that was shunned by others of its species.

“It was attacked as being kind of unique, which isn’t unusual in animals,” Marzluff said. “Unique ones are often pestered more … there’s definitely social and predatory selection against being unique in a bird.”

But from a human perspective, seeing a rare bird can be exciting — especially with an incidence as low as one in 10,000.

“I think it’s great to bring to the attention of people and enjoy this variability that occurs in nature,” Marzluff said.

As for the photographer, he’s heading back to the pond this week to see if he can spot the crow again. Peremiczky goes walking with his camera every day and loves documenting the nature he sees in the Lower Mainland and on road trips up to the Yukon.

In November, he photographed a baby bobcat napping in a tree at Burnaby Lake.

Megan DevlinMegan Devlin

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