Training a good birding dog

March 20, 2015 is the day I drive to Chicago to pick up my new puppy. Pip is a brown and white Havana Silk Dog—a little foo-foo dog with fluffy straight fur, of the same breed that Charles Dickens had. I’ll be training her from the start to be my birding buddy.

The logistics of bringing a dog birding can be tricky, and dogs are forbidden from many birding spots, particularly where vulnerable species such as Piping or Snowy Plovers nest. If we lived in a culture where people were expected to train their dogs and keep them under control, on- or off-leash, and where people understood and appreciated local wildlife and the problems they face, leashed dogs would probably be allowed on all beaches that people are allowed on, but since American dog owners have a poor track record at controlling or cleaning up after their pets, it’s just as well to keep fragile nesting areas off-limits to all dogs.

When I was in Vancouver this fall, I spent three mornings walking along beaches. One stretch was marked as an off-leash dog park, but even where signs clearly stated that dogs were not allowed at all, people were running them on the beach, and even allowing them to chase birds. Several times right when I was photographing a cool bird, suddenly a dog charged in and chased it off. This was a minor inconvenience for me. But for the birds, it was not just cosmically rude, but potentially dangerous. In our increasingly developed world,  there are too few remaining places where birds can come down after a long flight, and where they can find adequate and safe food supplies.

So, obviously, the first rule I’ll be teaching Pip is

#1. No chasing birds!

How do you train a dog not to do what seems "natural"? It's best to start with a breed that wasn't specifically bred for chasing prey or chasing other dogs. If you start with a terrier, hound, or sled dog breed, you've already got the deck stacked against you. Oddly enough, bird-hunting pointers and retrievers often make splendid birding dogs, because they were bred to stop and wait when they find a bird on their own, and when they pick it up, to bring it straight to their human and hand it over. So they're predisposed to be compliant and to master their deepest instincts for their owner. My golden retriever Bunter made a splendid birding dog for that reason. My bichon frise Photon was also a splendid birding dog. Her breed was specifically bred for circus performance. Other related breeds that excel in agility events, in which they pay special attention to their owner's commands, are also often easy to train with regard to chasing.

Even my exceedingly well-trained golden retriever and my perfect little bird dog Photon occasionally had a strong temptation to chase a deer or mosey off along a fascinating scent trail. So I always kept them on leash while birding. I need two hands to deal with my camera and binoculars, so on birding adventures, I use a retractable leash with the handle hooked by a carabiner to my belt.

There are times, like along dangerous highways or when a potentially dangerous dog is approaching, when staying on heel or even being held is essential. Otherwise, I just want my dog nearby where we're both able to enjoy ourselves. Walking along country roads and trails, I always let my dog go a bit ahead or behind, sniffing at a whole world of things I don't have a clue about, but if I hear a bird up ahead and want to hurry, I need the dog to keep up with me. And if I'm watching a bird right there, I don't want to be jerked from where I'm standing. So I’ll be teaching Pip good manners on a leash while she’s little, using a regular leash at first. The important thing for her to learn will be:

#2. Don't pull on the leash.

She’ll also have to learn:

#3. Never ever lunge at or jump on people or other dogs, and
#4. Don't bark.

Little dogs often become barkers. Many people can't help but indulge small, adorable puppies, thinking those little barks are so cute. That lasts right up to the time that they become incessant yaps, when it's too late. So from the start, I’ll praise Pip for alerting me to something with one bark, saying "Good bark," but if I hear a second or third bark, it'll be, "Uh uh. You already told me about that." At that point, I’ll try always to pick her up and get her interested in something else, but if the barking continues, I’ll do what I did with Photon and Bunter: gently pinch a wad of fur on the scruff of her neck, where mother dogs nip naughty puppies. Bunter and Photon took even the softest “no” and gentlest pinch seriously, so I never had to do anything more severe to train them to follow basic rules.

I’ll have plenty of rules of my own to follow: cleaning up after Pip, paying attention to her needs even as I’m looking for birds, and noticing and protecting her from nearby dangers she might encounter. The first months will be taxing, but the hardest work will be required right when she’ll be at her most endearing. The end result will be having my very own plucky sidekick wherever I go. When I tell her we’re going birding, I'll say to her, as Joe Gargery said to Pip in Dickens’s Great Expectations, “what larks, Pip. What larks!”.

The Swallows of Capistrano

Cliff Swallows

According to the Catholic Church calendar, March 19 is the Feast Day of St. Joseph. It also happens to mark the day when swallows traditionally returned to the Mission at San Juan Capistrano.

The mission, founded in 1776 by Spanish Catholics of the Franciscan order, has had a fascinating history. An 1812 earthquake damaged much of the structures. In 1841, Governor Juan Alvarado declared the Mission a secular Mexican town, granting the few remaining residents rights of ownership or use of the land. In 1845, two Englishmen bought the Mission property under questionable circumstances. A smallpox epidemic in 1862 killed most of the native peoples of the area, and Abraham Lincoln signed a proclamation on March 18, 1865—the month before he died—restoring ownership of the mission to the Catholic Church.

Mission San Juan Capistrano, photochrom print by William Henry Jackson c. 1899

It’s hard to say when people first associated the Mission with Cliff Swallows, but a play by John Steven McGroarty titled The Mission Play, written in 1911, ends “amid the broken and deserted walls of Mission San Juan Capistrano (the Mission of the Swallow).” The Cliff Swallows may have started nesting on the structure as soon as it was built. According to legend, the birds first started nesting at the Mission when an irate innkeeper outside the Mission began destroying their mud nests, but the swallows were almost certainly attracted to the structure anyway because the Mission walls conspicuously rose above the landscape, and its location near two rivers made it an ideal location for obtaining both the mud necessary for building their little adobe nests and a constant supply of the insects for feeding adults and their young. The walls also provided protection against the elements.

 In 1915, an article in Overland Monthly, a California magazine, told the story of the birds' annual habit of nesting beneath the Mission's eaves and archways, and made the swallows the "signature icon" of the Mission. The pastor of the Mission at the time, a Father O'Sullivan, capitalized on the swallows to generate public interest in restoring the Mission. A popular tale was that the swallows (las golondrinas in Spanish) flew over the Atlantic Ocean to Jerusalem each winter, carrying small twigs on which they could rest atop the water along the way.

 On March 13, 1939 (six days before St. Joseph's Feast Day), a popular radio program was broadcast live from the Mission grounds, announcing the swallows' arrival. Composer Leon René was so inspired by the event that he wrote the song "When the Swallows Come Back to Capistrano," which became a hit released by many popular singers. A glassed-off room in the Mission was designated in the composer’s honor and displays the upright piano on which he composed the tune, the reception desk from his office and several copies of the song's sheet music and other pieces of furniture, all donated by René's family.

During all the time that the swallows were nesting at the Mission, they certainly never thought about St. Joseph nor about returning specifically on his feast day. But bird migration does have natural rhythms, and the birds most certainly tended to return by about March 19—as long as people could carefully avert their eyes to avoid noticing them before that date, they could count on their return on St. Joseph’s feast day.

There is something so deeply pleasurable in counting on the rhythms of nature that people all over the country loved hearing about the swallows’ annual return. As Rachel Carson wrote, “There is symbolic as well as actual beauty in the migration of birds. There is something infinitely healing in the repeated refrains of nature--the assurance that dawn comes after night, and spring after the winter.”

By the 1980s, the numbers of swallows returning were diminishing. At some point in the 1990s, I remember watching a CBS news story reported by Dan Rather about the birds’ return, only the cameras weren’t focused on swallows at all, but on swifts.

Cliff Swallow population trend in California, from USGS Breeding Bird Survey

Now few if any swallows nest on the Mission each year. Much of the loss is due to development. Optimists claim that now there are many more structures for the birds to use. But the truth is, Cliff Swallows are declining significantly throughout California. Pollution and overuse of the limited water resources have destroyed populations of mayflies and other valuable insects essential for fueling their migration and feeding families during the breeding season. Extended drought conditions exacerbated by overuse of water may also have decreased the supply of useful mud for building.

It mystifies me how people who treasure our nation’s human history and traditions don’t seem to see how much we lose in terms of human values as well as natural ones when our most beloved species decline. We learn as children that people eventually die, buildings and businesses and whole cultures and civilizations eventually fall apart, but the one thing we can count on—the one thing that gives us our very concept of permanence, or "forever"—is nature.

Watching the skies for swallows on St. Joseph's Feast Day may be at heart romantic silliness, but our trust in the future is fundamentally compromised when we sell out the permanence of nature’s rhythms for quarterly returns on our 401-Ks. I hope we figure that out before our society crumbles like the Mission’s walls.

Gifts from Birds and Other Internet Stories

Every day, people send me bird stories, pictures, and videos they’ve seen on the Internet. One kind irritates me—videos, invariably set to music, of captive birds, in rehab situations or from countries where wild native birds such as owls can be kept as pets, doing what superficially looks like funny or cute things. “Laughing” Snowy Owl pictures are invariably showing stressed or overheated birds panting.

Videos of cats or dogs playing with birds may sometimes be showing really well trained pets, but set up dangerously false expectations. Before I knew better as a rehabber, I used to let my golden retriever Bunter follow me everywhere. One time when I accidentally left her in a room with Blue Jay fledglings, I returned to find one baby jay hacking into her back like a woodpecker, and another leaning over on her snout, probing into her nostrils. This made for a wonderful story I’ve used for over two decades, but when I tell it, I add reasons why despite Bunter’s trustworthy nature, it was a horrible mistake to let this happen. Indeed, one of those jays ended up being unreleasable. During the period I was trying to acclimate her to the wild, she kept landing on strange people AND dogs—and was almost killed by a dog.

One video showing what is touted as a “snoring hummingbird” is actually showing a desperately stressed hummingbird coming out of torpor. That one and a lot of the ones showing young owls in rehab situations elicit comments on facebook about how people want a hummingbird or owl as a pet. Acquisitiveness is a quintessentially human quality, but in the context of possessing wild animals seems profoundly misguided. Why can’t we love wildlife on its own terms? If a photo of a lovely bird or mammal elicits yearning in us, why must that yearning be to own the animal rather than to experience it in the wild?

But as cranky as some viral wildlife videos and stories make me, some are wonderful. One of the stories making the rounds since last week is about an 8-year-old girl in Seattle who has been feeding peanuts to her neighborhood crows since she was a toddler. The crows came to recognize her not merely as a source of food, but as a comrade, and started bringing her little gifts, such as paper clips, Legos, rusty screws, beads, and a pearl-colored heart. She puts food for the crows into a dry birdbath, and they leave these gifts for her there, rather as Boo Radley left little gifts for Scout and Jem in a knothole.

It’s possible, of course, that the crows aren’t knowingly giving her gifts. Corvids carry food and other items in their throat pouch; if they come across a better morsel, they spit out what they’ve been carrying before they pick up the new item. So these gifts may simply be discarded items they don’t value as much as food. That would be my conclusion if the girl had found just one or two things in there, but they’ve left her so many things just since 2013 that it’s very likely that they really do intend them as gifts, or at the very least as a fair trade.

After this story went viral, other people started reporting on gifts they’ve received from corvids. After all my years of birding, I have only one story to offer. Back in 1981, I was staying with Russ’s parents for a couple of weeks while Russ and I were in the process of moving, and I took walks in Port Wing every morning. One day when I returned to the house, I noticed that my wristwatch was missing. It was on a leather strap, and the buckle had occasionally worked its way open. I thought it was lost forever.

The next day when I was three or four miles from Russ’s parents place, a raven flew over and made some interesting squawks I’d never heard before. A few minutes later, that or another raven flew over with something hanging out of its beak. I pulled up my binoculars, and there was my watch! The raven flew in, closer and closer, right over my head. And voila! It dropped my wristwatch at my feet.

The watch stopped working a year or two later, but I’ve never been able to throw it away. Somehow that raven had transformed my cheap old watch into a priceless treasure.

 

Fishicles

Photo copyright 2015 by Kelly Preheim

This winter has been colder than average over much of the Great Lakes—the ice cover over the Great Lakes system was at 88.3 percent as of March 1, and 94.1 percent of Lake Superior is ice-covered.

Here at the western end of the big lake, we can usually still see a big patch of open water, though that moves from day to day. The ice piles up on the South Shore when winds have a northern component, and on our side of the lake when winds are southerly, so our hopes of spring, pinned to that blue water, can be raised or dashed depending on which way the wind is blowing. Hamlet must have lived on the South Shore to be but mad north-northwest.

As the ice sheets slosh back and forth, colliding with the shore and other ice sheets, dead fish and other small aquatic critters at the surface end up getting embedded in the ice. By March and April, we see increasing numbers of crows, ravens, and eagles walking on the ice. When people ask me what they’re looking for, I explain about these frozen dinners, but I’ve never had a good photo of what’s happening, until I heard from Kelly Preheim, a kindergarten teacher and birder from South Dakota.

On February 28, Kelly wrote in her wonderful BirdTeach blog:

The lake at Lake Andes National Wildlife Refuge had a fish kill last year and in mid-March there were hundreds of Bald Eagles, American Crows and gulls at the lake in a feeding frenzy! It was quite loud amongst the flurry of wings and I was amazed at what I saw! This year is proving to be a repeat year. Today there were deceased fish scattered all along the surface with some fish in these vertical ice jams.

Photo copyright 2015 by Kelly Preheim

Kelly posted this amazing photo of fish trapped in the ice, and gave me permission to use it here. Apparently wind and wave action had pushed some ice sheets into a vertical position, and fish that had been trapped—probably dead on their sides when originally frozen—were propped up and appeared to be jumping—some looking quite alive within the ice sheet. She also added a photo of an eagle on the ice.

Photo copyright 2015 by Kelly Preheim

I’ve never ever seen anything so dramatic on Lake Superior. The oligotrophic nature of the lake—that is, its high oxygen content and low density of plankton and vegetation—and its sheer size, keep concentrations of fish down. Sure enough, the birds we see combing the ice aren’t nearly as concentrated on the lake as they are in Allouez Bay off Wisconsin Point, and even there I've never seen anything like what Kelly documented in South Dakota. She posted another photo to show how many eagles were gathered nearby.

Photo copyright 2015 by Kelly Preheim

Even if we can’t see the fish from shore in my neck of the woods in anything like Kelly's surreal photos, experienced birds know that fish are there, and even inexperienced ones discover them either by spotting them as they fly over or by noticing other birds picking away.  I’ve never flown over the lake myself, so I can’t be certain, but I’m sure there are both insects and fish, some mostly intact and some in bits and pieces sitting out there waiting to be eaten.

Up here in the north, ice sometimes remain in Lake Superior until May and some pockets close to the lake may not have much leaf out before June, so signs of spring can be subtle and easy to miss. Even our fish kills are apparently not as dramatic as they are in other places. Watching crows and eagles combing the decaying ice surface for bits of dead aquatic animals may not appeal to some people, but I’ll take the season as it comes.

You can learn more about Kelly Preheim's adventures with her students at Kelly's delightful  Kindergarteners on the Go! blog. And check out the Destination Nature facebook page and Kelly's flickr photostream:

https://www.facebook.com/DestinationNature

https://www.flickr.com/photos/rookiebirder/

One could do worse than be a watcher of birds

(Part of this was worked over from a blog post from my Conservation Big Year.)

Three weeks ago, I had a mild heart attack. I realized it early on, and Russ rushed me to the hospital before there was too much damage, but the following week I had a bad reaction to a statin drug and ended up back in the hospital again. That turned out to be more debilitating than the heart attack itself, but I'm pretty much recovered again. Even so, intimations of my own mortality, which have been whispering for a few years now, suddenly have grown more insistent.

In addition to the heart attack, the past two months have provided a couple of other disturbing signs of advancing age. In December I had two basal cell carcinomas removed from my face. Considering how much time I spend in the sun, I'm lucky I've never had any skin cancers before my 60s, and this is the least dangerous form of skin cancer, but it was nevertheless disconcerting.

Then last week I got fitted for hearing aids. Of course, people much younger than I need them, too, and my audiologist assured me that most people can deal with my level of hearing loss without hearing aids at all, but I need to hear high-frequency bird songs for both my field and radio production work. I've spent time with older birders who insist they haven't lost any of their hearing even as I watch them missing nearby birds singing away. I wasn't afforded that luxury of denial—for several months, I've not been able to hear part of a Cedar Waxwing recording I've been using for many years, even when I crank up the volume to the maximum. Realizing I'm losing my high-frequency hearing has been distressing but, like skin cancer or my heart attack, is exactly the sort of problem that can be solved only when faced full on.

As mortal as I suddenly feel, I’m hardly ready to turn in my binoculars. Jack Kerouac wrote, “Why think about that when all the golden lands ahead of you and all kinds of unforeseen events wait lurking to surprise you and make you glad you're alive to see?” I'm getting a puppy in two weeks, and looking forward to having her in my life has definitely given my days a luster of gold. It had never even occurred to me when I arranged to get her on the day she was born, January 2, that it might be possible I'd not outlive her. Ironically, I'm actually less likely to suffer a heart attack now that I'm on blood thinners than I was before we knew I had a congenital aneurism in a coronary artery. Yet, regardless of statistics, I have an unsettling, visceral sense of my eventual demise that I'd never felt before—a feeling that will be forever reinforced by the little vial of nitroglycerin I'm supposed to keep with me at all times, prescribed by the same professionals who say my chances are excellent that I'll never need it. Being certain Pip will be loved and cared for no matter what gives me a feeling of security and peace even as I love being pretty sure I'll be here to enjoy every day of her life.

Every morning, the sun rises earlier than the day before—at least if we keep our bodies set to Standard Time—and every day the birds in my yard get more vocal. One chickadee seems to own the territory right by my upstairs window, and starts the morning singing for three or four minutes before he takes an interest in mealworms. There's something reassuring in the certainty that he and my other chickadees are doing just fine, and will be singing, mating, raising young, and carrying on no matter whether I'm there to watch them or not, even as each day that I see them feels precious in a way I never appreciated before the heart attack.

For several weeks now, redpolls and siskins have been descending upon my feeders at first light. They're eating more than 30 pounds of seeds each week—about 20 pounds of sunflower and almost 12 pounds of nyjer. The bustling activity is keeping my spirits buoyed even higher than the longer day length and singing chickadees are raising them.

Watching these birds keeps me grounded in a world that is natural, true, and sincere, and enlarges my capacity for honest and joyous astonishment about astonishingly genuine, beautiful elements of this planet. And in two weeks, I'll be able to enjoy all this with a new puppy at my side.

I'll be starting the list of birds I see with Pip starting March 21, the day I get her. She will be coming with me on several trips this spring, as far as Ohio and Florida. If all goes according to plan, we'll see at least 200 species together between now and the end of May.

I don’t know how other people get through their days without at least occasionally blocking world and national events from their consciousness. I don't know how any of us can sustain a dream of making the world a better place without knowing, deep in our bones from real experience, just how beautiful the world can be. And I don't know how other people deal with the grim sense of their own mortality. All I do know is that one could do worse than be a watcher of birds. And how could one possibly do better than be a watcher of birds with a puppy?

New Beginnings

Black-capped Chickadee: #1 on my life list, first seen March 2, 1975

March 2, 2015, was the fortieth anniversary of my becoming a birder. On that Sunday in 1975, I spent over an hour in Baker Woodlot on the Michigan State University campus searching for a bird—any bird—and finally found and painstakingly identified it—a Black-capped Chickadee. Three days later, I saw my second species—Mallard—on the Red Cedar River on campus. Four days later I doubled my life list again when a European Starling and House Sparrow first visited the bird feeder Russ put up for me behind our apartment. I doubled my life list again on March 17, when Russ and I visited the Morton Arboretum outside Chicago and I added cardinal, crow, Canada Goose, and Bufflehead, bringing my list to 8. That also marked the last time I’d ever double my life list in a single day.

Bufflehead: #8 on my life list, first seen March 17, 1975

I was so inexperienced that it took forever to track down a distant movement or sound to find the bird, and then I had to work my way through the field guide trying to figure out what it was while it was still in view. I often missed, but by the time I finally did find and identify a singing bird, I’d securely memorized the song and worked through a lot of similar species in the field guide.

One day that spring, May 11, I added 10 lifers, including my first four warblers. The heady excitement of finding and figuring out all these new birds on my own was as intense as falling in love.

Magnolia Warbler: #33 on my life list, and one of the warblers I saw on May 11, 1975.

 I often encounter people who started their life lists at birding festivals or on organized field trips. A life list can mushroom that way—a morning walk with an expert in good midwestern habitat during migration can easily yield 50, 70, or more species, while at the end of my entire first spring of daily birding, my life list had reached only 40. But my slow initial progress paid off in the long run—the skills I was developing in finding and identifying birds, including learning their vocalizations, were solid.

I jumped on the fast track that June, when I took a field ornithology class at the Kellogg Biological Station, near Kalamazoo, Michigan, more than doubling my life list in 3 weeks, bringing it to 90. The class was held 2 days a week, and I spent much of the remaining 5 days each week out searching for birds on my own. All that focus, day after day, helped me ace the field exams.

Scarlet Tanager: #60 on my life list, first seen June 23, 1975

I added 30 more lifers in 1975, ending the year with 120 species on my life list. The next year I brought it to 225. I reached the 300 mark in 1978, and broke 400 in 1980.

Barred Owl: #268 on my lifelist, seen May 7, 1978 in Wisconsin

Russ and I made trips to Texas and to southeastern Arizona, using bird-finding books by Jim Lane to tell us where to go and what to look for. Madison Audubon sent me on a trip to Estes Park, Colorado,  and I got to go on a trip, mostly camping, to many Western spots with my sister-in-law. I delighted in figuring out so many unfamiliar species in my old, plodding way, though I was much more skilled now, missing few of the birds I searched for. My romance with birds and my joy in finding and identifying them on my own were as overpowering as ever.

Plain Chachalacas: #297 on my life list, first seen December 28, 1979

Brown-capped Rosy Finch: #357 on my life list, first seen in Colorado on July 2, 1979.

California Quail, #394 on my life list, first seen in Washington August 18, 1979

Costa's Hummingbird: #429, first seen in Arizona on April 5, 1982

 
Things settled down when we had our first baby in 1981. I was just as passionate about birds, but my love was ripening into something integrated with family life. I was limited to watching them closer to home and on family vacations, so building my life list slowed down considerably. I didn’t break 500 until 1991, and didn’t get to 600 until 1999. In 2001, when my youngest was in high school, I took my first trips to Costa Rica and Trinidad, which helped me break 1000.

Now I have about double that, and my love for birds is as strong as ever, but it’s matured into a quiet, constant love rather than a red-hot acquisitive passion. So soon after my heart attack, I’m feeling mellow and Zen-like, happy to enjoy whatever comes my way without feeling any compunctions to chase down rarities.

Florida Scrub-Jay, #600 on my life list, first seen March 28, 1999

On March 21, I’m getting a puppy named Pip, and have decided to start a whole new list of birds seen with her at my side. We’ll be starting out when I pick her up at her breeder’s home in a Chicago suburb, so our first birds together will include many of the ones I first saw 40 years ago. I don’t expect her to master the differences between Empidonax flycatchers, or even the differences between a chickadee and a Blue Jay, and I expect that a small dog will be more inclined to moseying rather than high-powered bird chasing, just as I seem to be right now. But both heading to wonderful birding spots and sticking closer to home, my jolly little birding companion will give me a lovely way to start anew, just in time to mark the beginning of my fifth decade birding.

Pip, my future birding sidekick

 

"The Dress" and bird colors

"The Dress." The center photo is the version that went viral.  On the left and right are how that photo appears when "corrected," with the light balanced toward white and gold, and toward blue and black.

Last weekend, after a wedding on Colonsay, a Scottish island, the bride posted a photo of the dress her mother wore. One of the members of the band noticed that most of her friends seeing the photo online thought the dress was white and gold. People seeing the actual dress at the wedding itself knew it was actually deep blue and black, but most people seeing the photo, including me, were certain it was white and gold.

“The Dress” is not the kind of optical illusion someone can stare at and eventually see both ways—most people seem to see it one way or the other, and that’s that. The reasons it appears white and gold to most people are complicated—the digital photo was badly overexposed, and thanks to some graphics algorithms that set up white balance, the resulting photo colors don’t look anything like the dress itself would in most light. And somehow our eyes seem to pick up cues from the background to add another layer to the potential for getting the color wrong.

 One would think bird colors would be more straightforward than that, and they usually are, but sometimes bird colors are tricky. Most plumage colors are produced by pigments within the feathers. The main pigments in bird feathers produce shades of yellow, red, and brown to black. Pigments absorb specific wavelengths of light, and our eyes see the colors the pigments don’t absorb. A crow’s feather pigments absorb all the colors, so all we see is black. Pure white feathers have no pigments, so all the colors are reflected back as white. If you find a pigmented bird feather, such as one showing yellow, red, or black, it will look that color no matter how you hold the feather, whether light is bouncing off it or going through it.

This Blue Jay really is blue, along with black, white, and gray.

Some plumage colors are not produced by pigment. Not one American bird produces blue pigment, yet the feathers of Blue Jays, bluebirds, and Indigo Buntings are truly blue, thanks to their feathers’ structure. If you’ve ever zipped feathers together, you’ve noticed that they’re made of tiny branching structures, which are beautifully patterned when seen with a magnifying glass, and even more amazing under an electron microscope. In blue feathers, the beta-keratin that gives feather barbs their strength is arranged in an intricate nanostructure with air pockets that are exactly the diameter of the wavelength of blue light. So blue light is reflected while all the other colors simply pass through or bounce off and cancel each other. If you look at a Blue Jay feather from most angles, you see the blue wavelengths that are bouncing off it, but if you hold it so light passes directly through it, you don’t see that blue reflectance. The dark pigments absorb most colors, allowing the brownish gray to bounce back to our eyes.

Eastern Bluebird

Some people misunderstand the issue of structural vs. pigment colors, and so I frequently hear people saying there are no truly blue feathers in birds, when of course there are. The color of anything is due to nothing more than how light bounces off it to our eyes, whether that is due to structure or pigment.

Photo by Melopsittacus_undulatus_-Fort_Worth_Zoo-8a.jpg: Jerry Tillery derivative work: Snowmanradio [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

The best example of the combination of color types is in the body feathers of pet budgies. Wild budgerigars are mostly green. The green is caused by yellow pigments absorbing all wavelengths of light except yellow, and by the blue structure of the feathers bouncing back blue while allowing other wavelengths to pass through. We see both blue and yellow in balance, making them appear green. Some budgies are selectively bred to lack the yellow pigment. They still have the blue structure, making them appear true blue. Some are bred to lack that arrangement of the beta-keratin and air pockets, and no colors are reflected by the structure. If they still produce the pigment, they appear yellow. (The head feathers of wild budgies are yellow for this reason.) Some are bred to lack both the yellow pigment and the blue structure: they appear pure white. The areas of the feathers that are black have a dark pigment (melanin) that absorbs all the wavelengths of light.

Iridescent feathers on Mallard drakes usually appear green, but can take on blue or turquoise shades in some light.

   

Iridescent feathers may have a simple dark pigment, but the brilliant color we see is due to structure. Unlike blue, though, we see most iridescent colors reflected only when light bounces off in a specific direction, so even the tiniest hummingbird sitting in one spot can show lots of changes in the amounts of color in the gorget as it moves its head.

   

Fortunately, internet photos of hummingbirds don’t go viral, setting off flurries of people passionately arguing about what color they are. No matter how persnickety a birder is about bird colors, we save our passionate arguments about them for dresses.

Here's a good more in-depth explanation of structural colors in nature, from The Scientist.