Thursday, January 14, 2021

Despite their name, blue jays aren't blue

        After the colorful fall foliage turns to brown, it takes a while before Mother Nature offers up another splash of color. Spring brings forth bright green leaves, blooming flowers and birds dressed in their Sunday best, but first we’ve got to get through the dreary colors of winter.
        We occasionally see a bright spot amid the grays and browns in the coldest months of the year – a few purple berries left uneaten by the birds, for instance, or the occasional sighting of a cardinal. But mostly we’re left with muddy ground, dormant trees, and wildlife wrapped in their dullest colors to match their surroundings.
        And then a blue jay jets into our yard and reminds us that another color of the rainbow hasn’t
Blue jay (Paul Dacko)
 abandoned us entirely.
        Except that blue jays aren’t really blue.
        You read that right. The first time I heard about it – in my college ornithology class – I didn’t believe it either. Blue jays aren’t blue? How can that be? I can see their blue feathers with my own two eyes! And yet every scientific reference I’ve checked in the last 35 years – and I double-check every year or so, including this week – tells me it’s still true.
        In the natural world, there are red feathers and white feathers and yellow feathers and black feathers. There are green feathers and brown feathers and even a few purple feathers and orange feathers. But there are no blue feathers. They don’t exist. Anywhere.
        That means that blue jays aren’t blue, and neither are bluebirds. And if you think that an indigo bunting is actually indigo, you’d be wrong about that, too.
        According to every ornithologist and scientist I’ve spoken to – and there have been many – blue feathers are a figment of our imagination. Or as one birder called it, “a pigment of our imagination.” What looks to our brains to be a blue feather is, in fact, a blue-looking color generated by white light interacting with the three-dimensional architecture of the feather. It’s what scientists call a structural color, rather than a pigment.
        Most birds get their colored plumage from pigments in the foods they eat. That’s why many pink flamingos at zoos aren’t very pink – because they don’t get their natural diet of algae and crustaceans that results in their pink feathers. Blue pigments, like those in blueberries, are destroyed when digested by birds.
        According to a Yale University ornithologist, blue feathers are created when the cells inside the growing feather dry up, leaving behind an architecture made of keratin molecules – the same material as our fingernails – containing air pockets like a sponge. When white light strikes it, the keratin structure somehow amplifies the blue wavelengths while canceling out the red and white wavelengths, making the feather look blue. Even though it isn’t.
        Take it away from a white light source or mess with that architecture, and the feather won’t look blue any more.
        Now that I’ve explained the bizarre science behind blue feathers, my advice is to ignore it and appreciate the beauty of those blue feathers – regardless of how they’re formed. We need those splashes of color to help us get through the bleak winter days, and I wouldn’t want to take anything away from your enjoyment of our local blue jays.
        And if you can’t find a blue jay, point your eyes skyward on a cold clear day and take in the bright blue sky. As far as I know, it’s really blue. But don’t quote me on that.
        
        This article first appeared in the Independent on January 9, 2021.

Friday, January 8, 2021

Camera system could protect endangered whales

        The beginning of the calving season for North Atlantic right whales, one of the rarest marine mammals on earth, is looking promising with four newborn calves observed in December. But the outlook for the species, whose global population is estimated at only 360 individuals, remains grim. Between fishing gear entanglements and collisions with ships, more whales have died in recent years than were born.
        A new technology on the horizon may help to reduce one of those threats, however. A smart camera system invented by a team of scientists and engineers at the Woods Hole Oceanographic Institution is being tested in local waterways and could be deployed on vessels traversing the East Coast to reduce the threat of ships striking right whales.
        “The idea is simple,” said Woods Hole Assistant Scientist Daniel Zitterbart, who is leading the
North Atlantic right whales (WHOI)

project. “We took a commercial thermal imaging camera, highly stabilized for roll and pitch, and a computer algorithm that looks at images and tries to tease out what’s a whale compared to what’s a wave or a bird or whatever.
        “The key part is, if you’re in a large vessel and you know there’s a whale 300 yards in front of you, it’s probably too late for you to turn away from it,” he added. “Our aim is to push the detection range as far as we can, which makes things difficult on a rocking boat. But getting the range we need to make a difference for the animal is the objective.”
        A prototype of the smart camera system was tested last summer on a research vessel in Stellwagen Bank National Marine Sanctuary in Massachusetts Bay, about midway between Gloucester and Provincetown, where humpback whales congregate to feed each year. A similar land-based installation was also deployed at a busy shipping channel in British Columbia traversed by endangered Southern Resident killer whales. The initial tests were promising.
        “If you’re talking about very large vessels like tankers or cargo vessels, they may not be maneuverable enough for the detection ranges we get, but for cruise vessels, ferries and fishing vessels that are more maneuverable, it definitely can make a difference,” Zitterbart said.
        A little larger than a half-gallon milk carton, the camera system must be installed at least 15 feet above the water line to be effective. Within seconds, it can detect the presence of whales a mile or more away and alert the captain in time for the vessel to slow down or change course.
        Unlike human observers or spotter planes, which are occasionally used in the U.S. and Canada to watch for right whales and alert nearby ships, the camera system can spot whales in daylight and darkness with little effort.
        James Miller, an ocean engineering professor at the University of Rhode Island, invented a forward-looking sonar device about 20 years ago that could be used to detect whales, reefs and other obstacles to navigation beneath the water’s surface. He commercialized the product by founding FarSounder, a Warwick-based company with clients around the world. The company’s sonar devices can scan up to 1,000 meters in front of a ship moving at speeds of up to 25 knots to detect underwater obstacles.
        “Dr. Zitterbart's technology for detecting whales at the sea surface can be an important part of the solution for reducing ship strikes, one of the leading causes of death for large whales,” said Miller.
        Zitterbart said that sonar is a better detection method for sensing static objects beneath the water’s surface, but he believes his thermal camera system is more effective at detecting moving objects like whales that may only be noticed for a few seconds. Both technologies can be hampered by challenging environmental conditions.
        The recipient of the 2019 Young Investigator Award from the U.S. Office of Naval Research for his work on whale detection, Zitterbart previously developed a thermal imaging system for protecting whales and other marine mammals from underwater noise produced by the air guns used in seismic surveys.
        Assuming his tests are successful this year, Zitterbart plans to deploy his camera system on a number of vessels without his development team aboard to ensure that remote troubleshooting can be conducted effectively. Eventually, he hopes to find a company interested in commercializing the technology.
        “Thermal imaging systems are a powerful new tool in real-time whale detection,” he told Ocean Insights. “Used alone or in conjunction with acoustic monitoring, this technology could significantly reduce the risk of vessel strikes.”
    
        This article first appeared on EcoRI.org on January 7, 2021.