A cardinal of a different color

A male Northern Cardinal with a rare mutation has become an Internet sensation!

Former shelter kitty Lucky Wilbury, who is currently recovering from a life-threatening bladder blockage.

To commemorate this avian celebrity (and gently rib certain curmudgeons in the birding community), I created this homage to Andy Warhol’s colorful silkscreen portraits of celebrities. It’s now available in my Mountain-Gem Arts store on Zazzle on men’s, women’s, unisex, and kids’ T-shirts, sweatshirts, hoodies, and more in a variety of bright, medium, and dark colors, including many bird-friendly options. A cropped version including the left and center panels is available for your wall and as a 2-inch square button to adorn your Tilley hat or birding vest (or as one of your minimum 15 pieces of flair).

Proceeds from sales of this design (and everything else in my Zazzle shop) will help defray the cost of recent lifesaving veterinary treatment for my indoor-only rescue kitty, Lucky Wilbury.

 

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Search of the Week: “it is september why am i only getting female hummingbirds at my feeders…”

In juvenile plumage, young male hummingbirds like this Ruby-throated usually look a lot like their mothers. They also seem to leave the nest with chips on their shoulders.

The full search was: “it is september why am i only getting female hummingbirds at my feeders and she is very aggressive”

By September, most of the migratory hummingbirds remaining at northern latitudes will be young birds of both sexes, which look like adult females except for variable amounts of pale fringing on the iridescent feathers of their backs and heads (plus a few other subtle differences, depending on species). Young males often show lines of dark spots on the throat, a pattern hummingbirders call “five-o’clock shadow.” Some young males will show bright flashes of color in their gorgets as adult feathers replace drab juvenile ones.

Though females of any age can be very aggressive and territorial, especially in migration, it’s the young males that seem to be the biggest troublemakers (as though they think they have something to prove). As long as there are still good numbers of hummingbirds around, expect the screeching, chasing, grappling, and chest-bumping to continue.

Keeping hummingbird feeders clean

Brushtech Hummingbird Feeder Cleaning Kit at Amazon.com (click image)

If you’re like me, you’ve got a collection of toothbrushes, baby bottle brushes, and even well-washed mascara brushes sitting next to your kitchen sink for cleaning hummingbird feeders. The problem is that tools made for other cleaning jobs don’t always work as well for such a specialized task, so it’s nice to see a set of brushes made especially to reach the nooks and crannies of typical hummingbird feeders. The big brush in this set could even get into the enclosed bases of some of the cheapo feeder models to remove crud you can’t see.

Of all the nasties that grow on hummingbird feeders, the nastiest and hardest to control is black mold. A 15-minute soak in a dilute solution of chlorine bleach*⇓ (1 part bleach in 10 or more parts water) is very effective at killing black mold on non-porous surfaces, but an hour-long soak in white vinegar is a less toxic alternative (NEVER use bleach and vinegar together: you could kill yourself!). In either case, follow up the soak with a thorough brushing to remove dead mold colonies and other organic growths, then rinse well and let the feeder dry before refilling to allow the odor to dissipate.

An even safer mold killer that’s much kinder to your nose than bleach or vinegar is 3% hydrogen peroxide, the medicinal kind you can buy in any drug or grocery store. The downside is that it’s much more expensive than bleach or vinegar. A frugal alternative to traditional soaking is to add a couple of ounces to the feeder bottle, screw on the base, invert the feeder and swirl gently over a sink or bucket to make sure the peroxide covers all inside surfaces, then allow it to stand for at least 10 minutes. While the peroxide is doing its work from the inside, spray the outside with more peroxide to kill any mold growing there. Follow the treatment with a good scrub, including the ports. and rinse well to remove any debris. No drying needed; the peroxide will leave no odor, and the only residues are water and oxygen.

This advice applies mainly to bottle-style feeders. Saucer feeders such as the Aspects Hummzingers can be cleaned by hand using dish detergent and the small port brush in the kit above or washed on the top rack of the dishwasher. If any stubborn debris accumulates in the built-in ant moat, the little ball-shaped brush in the Brushtech set will swish it away.

Regardless of what type of feeder you have, it will need cleaning and refilling every 1 to 2 days in hot, windy, and/or rainy weather and every 3 to 4 days in cooler, calmer, drier weather, whether the birds have emptied it or not. If you can’t make a commitment to good feeder hygiene, it’s best to plant flowers instead.

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* There’s a persistent myth that using chlorine bleach to clean feeders will kill hummingbirds. It won’t as long as you rinse the feeder well, just as you would if using bleach to disinfect your own dishes or your pets’ dishes. Any minute traces of chlorine residue will be rendered harmless by reacting with the sugar in the feeder solution (the same thing happens when you mix sugar with chlorinated tap water).

What Not To Wear Cranewatching

The Sandhill Cranes that winter at Whitewater Draw Wildlife Area have grown accustomed to crowds of humans ogling them from the trails and viewing platforms.

Sandhill Cranes have returned to southeastern Arizona for the winter, and I’ll be visiting the flock at Whitewater Draw Wildlife Area almost every weekend between now and the end of February. When you have the privilege of spending a lot of time with cranes, you get to see lots of interesting behavior and interactions. Some are hard to miss, but the subtle ones can be the most educational.

One Sunday last February, I was leading a crane watch activity for the public on one of the viewing platforms at the wildlife area. Uncommonly cold temperatures that day kept most visitors away, but a handful of hardy souls joined me to watch the midday crane fly-in. The viewing platform has no roof or walls to block the wind, but spectacular unobstructed views of thousands of cranes made the eye-watering cold worth braving.

Drought had shrunk the playa lake to its lowest level in many years, and the scarcity of open water encouraged the cranes to land even closer to the viewing area than usual. They dropped in a few dozen yards in front of the platform, often skating across patches of ice (and sometimes falling down). The nearest birds cautiously picked their way across the frozen mud to a narrow band of open water a few yards from the platform and bent their long, graceful necks to drink. Camera shutters clicked madly, recording the spectacle.

The idyllic mood was broken by a sudden commotion east of the platform: a group of cranes scuttling warily away from a popular viewing spot on the trail, their necks extended and red crowns expanded in alarm. Peering through the leafless willows to see what had frightened the cranes, we saw four men dressed in varying degrees of hunting camouflage. All wore shirts and billed caps in camo patterns, and at least one wore coordinating pants. They weren’t accompanied by a dog (whose mere presence, even leashed, is known to have negative effects on birds and other wildlife), and none were carrying rifles or shotguns.

A dozen or so people in street clothes of various colors and at least three leashed dogs had already walked past that same spot without discouraging the cranes from approaching the trail. Maybe one of the men pantomimed shooting at the cranes, but it seems more likely that the older, more experienced members of the flock had learned to associate camo-clad humans with danger and reacted to the clothing alone.

Though I’m a strong proponent of dressing inconspicuously for birding, this experience has caused me to have second thoughts about whether hunting-style camo is a good choice for field wear, at least for watching cranes and other hunted birds.

Beware the wrath of the birding legions!

(Title borrowed from a column by the late, great Molly Ivins.)

On Monday morning, the New York Daily News broke a story about the Port Authority killing Snowy Owls at airports in New York City. Follow-up articles contrasted trigger-happy NYC with the more responsible and humane policies of Boston’s Logan Airport (a famous location for wintering Snowy Owls). The story quickly spread via Facebook, prompting a petition and phone campaign to stop the carnage (three owls had already been shotgunned by the PA’s euphemistically named “wildlife specialists” after five others struck planes).

Usually such efforts take days, weeks, or months to bear fruit, and some never do, but by Monday evening the PA had come around and agreed to stop slaughtering the owls and cooperate with trapping and relocation. The outrage from the public, including the birding community, was so swift and so fierce that it overcame bureaucratic inertia.

Every day on social media we see calls to action in support of one good cause or another or against the latest outrage. It’s good to know that raising our voices and signing our names can make a difference.

“Never doubt that a small group of thoughtful, committed citizens can change the world; indeed, it’s the only thing that ever has.”  — Margaret Mead

Dispatches from the West preview: September/October 2012

Male Montezuma Quail by Sheri L. Williamson

Montezuma Quail are the topic for my final “Dispatches from the West” column in the September/October issue of WildBird magazine. Here’s a teaser:

Our hearts pounded as we drank in every detail of his harlequin plumage. The quail stared back, and we could almost hear the gears slowly turning in his head. It finally seemed to dawn on him that he’d been spotted, and he slowly turned and strolled away, watching us over his shoulder.

This is usually where I encourage you to subscribe if you don’t already, but it’s too late. After being informed that WildBird was downsizing and no longer able to publish my column, I was saddened (but not surprised) to learn that the magazine will soon cease publication entirely.

WildBird‘s parent company, Bowtie Incorporated, publishes annual special issues on popular topics, and I hope to contribute to any issues covering wild birds. I’ll also be releasing my past columns and articles, along with other selected writings, in e-book form later this year. Thanks and best wishes to the staff of WildBird for so many years of reading enjoyment, and thanks to the subscribers and newsstand readers for supporting the magazine.

Dispatches from the West Preview: March/April 2012

My column in WildBird magazine changed focus recently from backyard birding to western birding. Here’s a teaser from the March/April column, entitled “Bird prepared,” about a spring visit to Big Bend National Park:

The birds had gone quiet, so now we paused only to catch our breath. Neither of us noticed the waning light until a few raindrops hit our bare arms. Overhead, tendrils of mist trailed over the jagged South Rim. Just an isolated desert shower, we thought. Nothing to worry about, surely, and the cool air feels nice.

If you’re not yet a subscriber to WildBird, you can use this link to Amazon.com to get six colorful, information-packed issues (a full year) and benefit the conservation and education programs of the Southeastern Arizona Bird Observatory (SABO). Single copies of Wildbird are also available at newsstands and bookstores. You’ll find subscriptions to WildBird and other birding magazines plus field guides, feeders and accessories, seeds for hummingbird-friendly plants, and more at SABO’s online shop, The Trogon’s Nest, powered by Amazon.com.

Orange-throated hummingbirds: Not so mysterious after all

The gorget of a male Ruby-throated Hummingbird in mid-September consists mainly of older orange feathers with a few fresh red ones.

Note 1: This post is about orange throats in normally red-throated male Ruby-throated Hummingbirds. If you’re trying to identify a hummingbird with an orange throat, start with Rufous Hummingbird. For additional hummingbird ID help, please refer to A Field Guide to Hummingbirds of North America in the Peterson Field Guide Series.

Note 2: This is a blog post, not a peer-reviewed article, and I’m personally acquainted with the people mentioned. Therefore, I’m dispensing with the artificial formality of referring to them by their last names.

The late-season color shift in hummingbird gorgets, a phenomenon familiar to hummingbird banders, has caught the attention of David Sibley. Unfortunately, a red herring had David barking up the wrong tree (it was an arboreal herring).

The source of the misdirection is an article in the September 2009 issue of Birding, “The Alternate Plumage of the Ruby-throated Hummingbird,” in which Donna Dittman and Steve Cardiff documented late summer/early fall molt (another phenomenon well known among hummingbird banders, though apparently none were consulted for the article). Extrapolating from Donna and Steve’s contention that Ruby-throated Hummingbirds undergo a more-or-less complete fall molt into “alternate” plumage (only to molt again in late winter—a dubious scenario), David hypothesized that the orange gorget color observed in some male Ruby-throateds in fall and winter is acquired by molt and constitutes a dull winter plumage. Comments from hummingbird banders Cathie Hutcheson and Scott Weidensaul encouraged him to reconsider, but I’d like to take this opportunity to review what we do and do not know about seasonal color changes in hummingbirds.

Though they don’t fade in the way pigment-produced colors do, the iridescent colors of hummingbirds do change over time. The exact mechanism by which this happens has yet to be documented (at least in published form), but the short answer is that it involves wear and/or bleaching rather than an additional complete molt.

To get to the long answer, it helps to know a bit of the science behind the colors. Iridescence is produced by thin layers of substances of different refractive indices, such as a film of oil on water. The refractive index is the speed at which light passes through a substance; it’s responsible for the bent appearance of a pencil in a glass of water. Refractive index values are based on the speed of light through a vacuum, which is assigned a value of 1. The higher the number, the slower the speed. The refractive index of air is 1.000293, water’s is 1.3330, and that of ordinary glass ranges from 1.523 to 1.925.

In the feathers of hummingbirds, layers of microscopic bubble-filled discs of melanin, known as platelets, are the primary source of the refractive and interference effects that create the birds’ brilliant colors. According to Crawford Greenewalt (1960), the refractive indices of the melanin and the bubbles are 2.2 and 1.0, respectively. Different colors are produced by variations in the relative thicknesses of the melanin matrix and the bubbles (the average refractive index). Thicker melanin (higher average refractive index) pushes the iridescent color toward the red end of the spectrum; larger bubbles (lower average refractive index) push it toward the violet end. Using a spectrophotometer, Greenewalt found an average refractive index of 1.85 for hummingbird feathers that iridesce red and 1.5 for those that appear blue. Following the order of colors in the spectrum, a green feather’s average refractive index would fall between 1.5 and 1.85, while the value for a violet feather would fall below 1.5.

Anna’s Hummingbird gorget showing shift to coppery orange on exposed distal portions of the feathers and retention of fresh hot pink color on basal portions protected by overlying feathers.

In his follow-up post, David points out that a change in wavelength from red to orange would require a change in the thickness of the platelets. He imagines this as a collapse, but physical abrasion and/or degradation by exposure to sunlight seem like far more plausible explanations. This is supported by detailed examination of individual feathers, which show a color shift on more exposed parts and the original color on more protected parts (illustrated in the photo at right).

The change in refractive index may result from thinning of the feather’s outer layer of transparent keratin (refractive index = 1.56; Osorio and Ham 2002), complete removal of the keratin layer and abrasion of the melanin matrix of the top layer of platelets, or changes in porosity that alter the refractive index of the keratin and/or melanin. Any of these would lower the average refractive index of the iridescent structures and push the color toward the violet end of the spectrum. Over time, a feather that started out bright red would be expected to shift to orange, yellow, and perhaps even green as more of the higher refractive index material (melanin and/or keratin) is removed or degraded, and that’s what we see in nature (even in the less intense green iridescence of the back feathers, which tend to be more golden green in spring and more emerald in fall).

There’s little doubt among hummingbird banders that the shift from longer to shorter wavelengths is the result of wear and aging rather than molt, but only electron microscopy of fresh and worn feathers can reveal the mechanism responsible. I don’t personally have the resources to pay for specimen preparation and EM imaging, but if someone with deeper pockets and/or university connections can provide the microscopy services I’m sure I can round up some feathers.

Addendum 1: Another photo of a male Anna’s showing the color contrast between extremely worn and new crown feathers.

Anna’s Hummingbird crown in early fall, during replacement of gorget and crown feathers.

Addendum 2: A macro photo of a male Anna’s gorget at the beginning of gorget molt. The purple/fuchsia feathers at the bottom edge are new. The color shift on the older feathers is most dramatic on the barbs, which are more exposed than the barbules.

Click on the image to view at full resolution. ©2015 Sheri L. Williamson.

References:

Dittmann, D. L. and S. W. Cardiff. 2009. The Alternate Plumage of the Ruby-throated Hummingbird. Birding 41: 32–35. Part 1 Part 2

Greenewalt, Crawford. 1960. Hummingbirds. (Dover reprint, 1990.)

Osorio, D. and A. D. Ham. 2002. Spectral reflectance and directional properties of structural coloration in bird plumage. Journal of Experimental Biology 205, 2017–2027. link

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Out the Window preview: July/August 2011

Here’s your bimonthly teaser for my “Out the Window” column in WildBird magazine:

It was a cool but sunny morning during fall migration, and the yard was bustling with bird activity. Hordes of ravenous Lesser Goldfinches swarmed the thistle sock, a dozen Gambel’s Quail queued up to drink at the water feature, a handful of White-crowned Sparrows scrounged seeds dropped by the resident Pyrrhuloxias and Curve-billed Thrashers, and four descendents of Red Junglefowl—our pet hens Joni, Bonnie, Grace and Pearl—chased grasshoppers, scratched in the dirt, and basked in the autumn sun.

Chickens in a birding magazine?!? Equal-opportunity bird lovers who are not yet subscribers to WildBird can use this link to Amazon.com to get six colorful, information-packed issues (a full year) and benefit the conservation and education programs of the Southeastern Arizona Bird Observatory (SABO). Single copies of Wildbird are also available at newsstands and bookstores.

You’ll find subscriptions to WildBird and other birding magazines plus field guides, feeders and accessories, seeds for hummingbird-friendly plants, and more at SABO’s online shop, The Trogon’s Nest, powered by Amazon.com. Father’s Day is June 19—shop now for that bird-loving dad or granddad!

A lily-trotter by any other name

A Northern Jaçana in Belize

Pedantry loves company, so I was glad to see Julie Zickefoose setting the record straight on how to pronounce “jacana.” In the world of bird-naming mistakes, this one seems relatively minor, but it’s a headache for those of us lucky enough to travel in the Neotropics.

At issue is something that’s missing from the “c” in most renderings of the name: a cedilla, which in the Portuguese transcription of the bird’s Tupi name (jaçanã) indicates that the letter is pronounced as “s,” not “k.” When Linnaeus transcribed the name into Latin, he should have changed the “ç” to an “s.” He didn’t. Neither did anyone who came after him, so now we’ve got English speakers pronouncing it as “jah-KAH-nah,”  “juh-CAN-uh,” or “juh-KAY-nuh,” Spanish speakers and bilinguals pronouncing it as “ha-KAH-nah,” and rare pedants such as Julie and me sticking to our guns with variants on “zhah-suh-NAH.”

Having to explain yourself every time you use the original pronunciation is the pits, so I resolved for last month’s Belize tour that I would finally give up trying to pronounce it correctly. It would be “ja-KAH-nah” for my group, “ha-KAH-nah” for Spanish-speaking acquaintances.

It didn’t work out that way. The Brazilian pronunciation kept slipping out, and I sounded like a complete idiot trying to change it in mid-word to the Anglicized or Spanglicized versions (“Look, there’s another Zha… Ha… Jah…”). It’s not like Northern Jaçanas are rare in Belize, either. They’re thick around slow-moving fresh water, especially as the dry season shrinks the lagoons. After a couple of days around Crooked Tree Sanctuary, I was dying to get into the forested uplands just to get away from having to pronounce that name. No luck there, either. A living room-sized puddle along the road out of our upland lodge had a resident juvenile, so we saw at least one almost every day for the first week of the trip.

There’s an alternative that I wish would catch on: lily-trotter. Sure, it’s a little silly, but it’s in use in Africa (where a Tupi word seems out of place), every English speaker will know instantly how to pronounce it, and it fits so nicely with all the other hyphenated bird names in the tropics.

Northern Lily-trotter. On my next Belize trip, that’s what I’m calling them. No more “Zha… Ha… Jah….” Seriously.