Track & Field

cottontail leaping

Back to school, and to early morning practice before class – hop to it!

[Students are returning to my university town for the start of another academic year… so in honor of college athletics I’m offering a slightly-edited instant replay of this post about cottontail rabbits that originally ran back in April 2011.]

On your mark…. Get set… HOP!

An article I read while eating breakfast had me thinking about track meets as the terrier-boy and I set off for our morning walk.  That piece may be why I noticed, for the first time, how runners imitate the posture of a rabbit as they settle into their starting blocks. Human runners have to fold themselves up to gain the potential energy advantage of a crouching leg, but rabbits are always ready for the starting gun.

sprinters

In 2009, Usain Bolt set a record of just over 23 mph in both the 100- and 200-meter, but he’s an exception even among world-class athletes. It’s nothing out of the ordinary for Sylvilagus floridanus to reach speeds of 18 mph, and they can maintain that speed for close to 800 meters… while zig-zagging to change direction every few strides. Let’s see Bolt try that!

racing cottontailsMost sprinters are specialists, but cottontails and other Lagomorphs, with the exception of pikas (Ochotona princeps), also excel at hurdles, steeplechase, and in some field events. Okay, they can’t throw a javelin or a shot-put, but they leap to the top of the score board when it comes to jumping.

leaping cottontails

Longing to see a long jump? At first glance, a cottontail’s 4.8 m (15 ft) may not sound too impressive when compared to current world record holder Mike Powell’s 8.95 m (29.4 ft), set in 1991. But consider this: a 4.8 m leap is 10x the average length of an adult cottontail’s body; 9 m is barely 5x the average height of an adult American male.

How high can they flycottontail courtship? The men’s high jump record stands at 2.45 m (8 ft), set in 1993 by Javier Sotomayor of Cuba. That’s only 1.4x the average height of Olympic jumpers. While courting, both buck (male) and doe (female) cottontails will jump 0.6 m (2 ft), nearly twice their height, to demonstrate worthiness. By that standard, not even elite human athletes would be able to find a mate.

cottontail courtship 2Once the mating ritual (which also includes a little boxing, just to keep things interesting) is complete, 1-12 kits are born approximately 28 days later. A doe will often mate again within hours of giving birth—what a woman! Admittedly, she’ll only visit the nursery when it’s time to feed the kids so she’s not going to win any “most attentive mother” awards. But, to be fair, compared to her baby-daddy she’s a doting parent, and staying away keeps predators from getting wise to the location of the nest. It will take her 3 weeks to wean one set of youngsters, then she’s got about 1 week to recuperate before the stork arrives again.

Still not impressed? She may have up to 7 litters in a single year.  Now, I call that a marathon.

[Thanks to the following photographers for making their work available through the Creative Commons license: Porsupah ReeRob Helfman, and Michale Connell.  © 2011 Next-Door Nature. Reprints welcomed with written permission from the author.]

Lonesome Doves

It’s a fine world, though rich in hardships at times. ~ Larry McMurtry

There’s a sweetness in the lament of a mourning dove (Zenaida macroura) that makes the sorrow bearable, and believable. Theirs isn’t an pop tune about a hookup with a hook, or a power ballad tale of infatuation, thrill, and transitory heartbreak. When mourning doves call I hear a country-western melody about spacious, isolated landscapes and complicated lives composed of joy and calamity, love and betrayal, not to mention good and evil that can’t be easily differentiated by the color of someone’s hat.

Country music has had it’s share of singers who could wail with convincing anguish on stage, then party ’til the cows came home once the show was over… so I have to wonder if the mourning dove’s high lonesome yodel —coo-OO, COO, coo — is simply part of the act. After all, that grievous angel cry is replaced by a jaunty whistle of wings every time they launch skyward.

Plus, doves are rarely alone and don’t seem to have much time in their lives to feel lonely. The whole clan is known to grow up fast (reaching sexual maturity at about 85 days old) and then pair up into monogamous ’til-death-do-we-part couples who take the directive to be fruitful and multiply seriously… as in up to twelve chicks in a single season serious (six broods of two chicks each). Both Mom and Dad are doting, active parents who share grocery shopping and child care equally, rarely leaving their babes unsupervised by at least one adult at all times.

The end of the lovey-dovey breeding season shouldn’t bring on the lonesome blues either, because that’s when the community flocks together in a big way. They go on group picnics, gobbling up seed in open fields or from the ground beneath backyard feeders until their crops are full, then settle onto fences, or walls, or telephone wires to digest the meal and the days events. They go drinking together, although for doves that means sipping water from puddles and bird baths rather than throwing back with Jose Quervo at the neighborhood saloon.

The community even sleeps together— literally, not euphemistically — roosting in trees and other protected areas. Comforted by the safety of numbers, they’ll drop their heads comfortably between raised shoulders rather than tucking in beneath a wing or over the back as so many other birds do.

Despite all the social network support, there is a darker side to the life of a mourning dove that may explain their doleful song — they often end up on the wrong end of a gun. Mourning doves are abundant, with a population estimated to be comprised of nearly 500 million individuals, but they are classified as a game bird and are the most frequently hunted species in North America. As many as 70 million are shot by hunters each year. Those who dodge the bullet still have to contend with the threat of lead poisoning from shot picked up from the ground while feeding.

Despite what their name implies, though, when one of these doves becomes a widow or widower they don’t spend a lot of time in Brokenheartsville bemoaning their newly-single status. In fact, they pair up again pdq. After all, ya can’t be fruitful all by your lonesome.

 

[Thanks to the following photographers for making their work available through the Creative Commons license: Sarah Richter, Chuck Roberts, George Thomas, Tina :0), Edward Peters, and Patty Myrick.  © 2017 Next-Door Nature. Reprints welcomed with written permission from the author.]

King of the Road

[Here’s an oldie but goodie from back in 2010, with minor updates.]

There’s a wonderful word—one of my favorites— to describe creatures that are active at dawn and dusk. Crepuscular. It’s a popular time of day for many species, so the great outdoors gets lively when the light is low, and it’s a great time to see wildlife.

That is, unless you’re in a car.

Challenging light conditions can conceal an animal near the road and reduce a driver’s response time when something darts out. While driving at twilight, it’s important to scan the shoulders for movement or for the telltale shine of eyes reflecting headlights. Vehicles are a constant threat to wildlife, and my time running a large urban rehabilitation center provided more than enough evidence to support that claim.

Of course, I should know better. But, lost in thought on my way to the mall, I didn’t see the striped skunk (Mephitis mephitis) until he had sauntered into the middle of my lane. It wasn’t a major thoroughfare so I had the road to myself and, luckily, I wasn’t going very fast. I had time to cede the right of way. Good thing, too, because I knew better than to expect this black-and-white tough guy to blink. Fact is, he stopped and turned to stare down my Subaru.

The great horned owl is a striped skunk’s only one serious predator. Everyone else makes a wide detour, at least after being sprayed the first time. Since this particular crossing guard was a kit, the whole world has maintained a respectful distance—why wouldn’t he expect an automobile to follow suit?

If there’s enough time, skunks will usually give those who cross their path fair warning. According to mephitologist (skunk scientist) Jerry Dragoo of the University of New Mexico, a whole series of threat behaviors may occur before Pepe le Pew resorts to firing the big gun. Striped skunks will stomp both front feet, charge forward a few steps and then stamp, or back up while dragging their front feet before spraying the object of their wrath. They can discharge their weapon while looking you in the eye, using an over-the-shoulder stance or even a handstand.

I’ve heard stories in which a skunk was taking his or her time crossing the road, or was dining on some previously flattened wildlife, and clearly saw the car coming. Drivers have reported observing the kind of threat posturing described by Dr. Dragoo, although they did not recognize it as such. As their vehicle drew closer and closer, they wonder why the animal just stands there. Surely it will scurry off the road… any second now!

Instead, the skunk holds its ground, takes aim, and fires… and in the process becomes another scavenger’s meal.  Gone, but not forgotten.  Not until the fragrance fades, at least.

I’ve got good skunk karma, I guess. Either that, or this particular stinker was feeling mellow. Thirty seconds of holding my breath… then he decided to continue on his way and I escaped getting doused. My luck ran out a few minutes later at the mall, though. Still thinking about my skunk encounter, I swear I never saw that perfume saleswoman stamp her feet.

 

[Thanks to the following photographers for making their work available through the Creative Commons license: Desert MuseumTJ Gehling, and USFWS Mountain-Prairie.  © 2017 Next-Door Nature. Reprints welcomed with written permission from the author.]

Multi-Tasker

I found a blue jay feather this morning while I was out walking my dog, Dash. That isn’t remarkable — jays are a common species here, and because the color blue is relatively scarce in the natural environment (except for the sky) it’s eye-catching. I’ve started an informal collection, compiled on some shelves near my front door. I admire them on a semi-regular basis while running a Swiffer™ over household surfaces, and when I have to pick them up off of the floor because I’m cleaning like it’s a timed event.

As I ambled along, spinning the feather between my thumb and forefinger, I could feel it lift at the slightest breeze, attempting to return to the sky. I started thinking about the versatility of this keratin assemblage, this trinket both delicate and durable, this multi-tasker extraordinaire.

I’m well aware that researchers say multi-tasking is a myth, at least when it comes to the human brain. We only think we’re doing several things at once, the scientists tell us; actually, we’re just toggling back and forth from one thing to another, which reduces our mental efficiency and even lowers (temporarily) our IQ.  I’m mostly convinced by these studies but, full disclosure, neuroscience isn’t my field so I’m only familiar with what’s summarized and reported by the media… and by “media” I mean NPR. In light of all that has been reported, though, I find it even more fascinating and frustrating that handling more than one task is trivial for so many other, less admired, anatomical features. Wouldn’t you expect our much-lauded gray matter to be every bit as masterful at multi-tasking as, say, a feather?

Think about it…

First of all, feathers allow birds to fly — a feat humans have still not managed to accomplish, even though we reassure each other constantly that we have the largest, most amazingly intelligent brains on Earth (clearly, though, ours is not the most self-confident computer on the planet).

Now, before you think I’ve somehow overlooked the fact that thousands of human beings are flying from one global location to another all day, every day, and have been doing so for quite some time, let me interject that human beings have, without question, figured out how to make machines fly (with the aid of metallurgy and fossil fuels, of course). But we have never, not once, jumped up from the ground or launched from a tree branch to flap off into the wild blue yonder. Superman doesn’t count because he isn’t human, and wing-suits don’t count either because that’s gliding, not flying. Humans ride, birds fly, and they do it by flapping feather-covered arms, using renewable energy sources like insects, berries, seeds, and sugar water.

Next, consider that feathers also provide thermal insulation. This should come as no surprise because people use bird feathers to keep warm, too. We stuff clouds of down and feathers in-between layers of rip-stop polyester made from recycled plastic water bottles to manufacture vests and parkas. Then we slip on the garment, zip up the front, and head out into the elements to do some birdwatching.

Birds can waterproof their feathers with bio-oils stored in a convenient uropygial/preen gland at the base of their tail. This is handy because, having allocated their arms to flying, they can’t hold a spray can of Scotchgard™. Nor are they able to use hammers, saws, and other tools to build a roof overhead that will shield them from rain, sleet, and snow, or to build a boat when they want to go fishing.

But wait— there’s more! Bet you didn’t know that feathers are also an effective communication device. See, humans use an broad assortment of products, including designer label clothing, team-sponsored gear, our vehicles, digital devices, and jewelry to make nonverbal announcements about our group affiliations and availability.

Birds accomplish the same thing using their birthday feather-suits. The colors and patterns they wear say more than any Tinder profile or list of Who’s Who ever could.  Female birds assess a suitor’s sartorial presentation to determine if he’s her type, and male birds parade their plumage to show the ladies they’ve got the goods to be a quality life-partner. Or maybe just a handsome hookup, depending on how the species swings. Those same feathers can be used to warn a trespasser that this territory has been claimed, or warn a romantic competitor to back off.

Kind of puts the old uni-tasking cerebral cortex to shame, don’t you think? And all this time I’ve been under the impression that “featherhead” was an insult.

 

[Thanks to the following photographers for making their work available through the Creative Commons license: bagaball, Richard Hurd, Jonathan Fox, Ingrid Taylar, and Putneypics.  © 2017 Next-Door Nature. Reprints welcomed with written permission from the author.]

Hammers and Hydrangeas

Sometimes green means stop, look, and pay attention.

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Productivity.  A word that has long enjoyed favored status in U.S. culture. Americans are always trying to do more work in less time so we can… do even more work. We purchase time-saving apps and appliances and then fill the promised free-time that closed the deal with new projects and expectations.
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As the saying goes, when you’re a hammer everything looks like a nail. Of course, that assume you stop the work of pounding away occasionally to look around.
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I aspire to a zen “be here now” life but most days I miss the mark by a wide margin. Instead, I hammer down each nail on my to-do list, usually thinking about the next task or the one after that before completing the current one (and often ending up with a swollen thumb as a result). Yesterday was no exception.
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Until, suddenly, it was.
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Exiting my car with plastic shopping bag handles queued up along my forearms I charged down the sidewalk, mental blinders on, jaw set. Still, I did notice the row of tall limelight hydrangeas that hug my red brick building slouching beneath their load of heavy, fragrant, pale chartreuse blooms buzzing with activity.  “Honey bees,” I assumed dismissively, since a nearby restaurant keeps several hives, and continued on without breaking my stride.
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Then I was blinded by the light of a sunbeam reflecting off an iridescent copper-green carapace.
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I stopped in my tracks, oblivious to the increasing numbness in my hands, and watched one green June beetle (Cotinis nitida), then several more, stumble drunkenly around and through the blossoms. Glancing at other blooms I saw all kinds of colorful insects had shown up for the banquet, including other beetles and bees, butterflies, moths, flies, spiders, and wasps.  The realization that I was, yet again, missing my life for the sake productivity hit me over the head like a ball-peen.
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Time to take a deep breath and smell the hydrangeas. I rushed inside, left my groceries in a heap on the kitchen table, hurried back downstairs, out the door…
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and…
             slowed…
                                 waaaaay…
                                                          down.
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I spent the next hour losing track of time while I conducted an informal census of bug life in the flower gardens around my building and neighborhood. My goal was enjoyment, not identification. Eyes opened wide. Really seeing.
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composite greens
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red-orange-yellow composite
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purple composite
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bright composite
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How easy it is to forget that being unproductive is sometimes the most important work of all.
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© 2015 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work  but please ask). Green June beetle photo by the author (CCL).  Thanks to these photographers for making their work available on Flickr through a Creative Commons license: Jon K.;  Bill Bumgarner; Shellie Gonzalez; Andy Reago & Chrissy McClarren; doni19; Vincent Parsons; Photoguyinmo Swatzell; Dave Thomas; and USFWSmidwest.

Headbanger

 

Male downy woodpecker (Picoides pubescens)

The male downy woodpecker is a dapper urban resident (iStock, used with permission)

Rushing out the door, I went over the list in my head. Workout pants and layered tees—check. Running shoes—check. Coat, hat, gloves—check. Keys and sunglasses—check. MP3 player—check. Everything was in order as I pulled out of the driveway.

Or so I thought.

Fifteen minutes later I pulled into a parking space at the Power Valley Conservation Nature Center, a 112-acre oasis in suburban St. Louis created by the Missouri Department of Conservation with hilly trails perfect for raising my heart rate for 30-40 minutes. But as I stepped out of the car and began to gather my gear I realized with dismay I’d left behind a critical component—my earbuds.

The thought of a run without my workout mix, and without any caffeine in my system either, was disheartening. I need the motivation of a musical pulse. But I didn’t have time to go back to the house so I set off anyway, prepared to suffer.

About 10 minutes later I realized I was running to a faint drumbeat. At first I thought someone who had NOT forgotten their audio equipment had the volume on their iPod turned up to 11. Once I realized the thumping came from the woods themselves, though, it wasn’t too long before I spotted the drummer, dressed more appropriately for jazz than heavy metal in the stylish black-and-white houndstooth jacket and jaunty red cap of a male downy woodpecker. In spite of the bird’s diminutive size—no more than 6” from head to tail-tip and weighing in at an ounce or less—his wardrobe set him apart on that overcast day from the slate-and-silver hickory bark backdrop.

Downy’s are capable of making a noise disproportionate to their size. When a woodpecker is looking for a mate or claiming a territory, the sound of drumming needs to carry; building a nursery cavity using a beak as a jackhammer isn’t quiet either. But if you’re in the woods and the beat is more bongo than bass, hunger is probably acting as the drummer’s muse. A gentle tap, tap, tap betrays hollow spots beneath the bark where wood-boring insect larvae wait.

drawing of a woodpecker's tongue

Woodpeckers can really stick out their tongues (Florida Center for Instructional Technology, used with permission)

Once dinner has been detected, things get… interesting. That short chisel of a beak hardly prepares you for what’s inside—like many other woodpeckers, the downy has a barbed, sticky, and flexible tongue so long it wraps around the skull when at rest. If ever there was a bird ready-made for rock ‘n roll, it’s the woodpecker. Gene Simmons got nothin’ on these headbangers.

The whole tone of my morning changed in an instant. It’s so easy to carry a personal soundtrack wherever I go that I forget about everything I normally tune out when I turn up the volume. As a result of my oversight, I suddenly had a standing-room-only ticket to a great live performance, one I would surely have missed had this excursion proceeded according to plan.  My run could wait. I stayed for several encores and gave that downy an enthusiastic round of applause as he flew off toward his next gig.

[This post was originally published in January 2011. Hope to have a new installment ready for prime-time soon.]

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love-earthThis blog, like so many activities that foster support and appreciation of the natural world, is a labor of love. If you’ve enjoyed learning about the creatures who share our built environment, consider becoming an NDN Benefactor with a donation of any amount you’re inspired to give. If you’d like to find a little Next-Door Nature surprise in your inbox just click the Subscribe!  button in the upper right-hand corner of this page and receive notifications of new posts!

© 2011 Next-Door Nature— no reprints without written permission from the author

Runner-up

Two male turkeys audition but fail to impress the judge (Photo: Teddy Llovet, Creative Commons license)

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I don’t know what American grade school kids are being taught these days—I left Oakville Elementary a couple of decades ago (okay, fine—several decades ago) and since I haven’t had kids of my own I don’t have access to 21st century homework assignments. But I’ll go out on a limb here and bet that most of them know the bald eagle (Haliaeetus leucocephalus) won the 1782 version of American Idol, and that it did so by edging out celebrity judge Benjamin Franklin’s favorite contestant, the wild turkey (Meleagris gallopavo).

That long-ago contest had little in common with the popular modern day version of reality TV. For one thing, neither bird has great pipes. Citizens were never asked to call or text in their votes. Also, the bald eagle has held on to national fame longer than fellow white-headed winner Taylor Hicks, while the turkey hasn’t exactly proven the voters wrong by, say, winning an Academy Award, Jennifer Hudson-style.

On the other hand, we don’t set aside a day each November (or any month, for that matter) on which the eagle takes center stage.  So in honor of Thanksgiving, I’d like to briefly sing the praises of the runner-up… and not just as the star performer at a holiday dinner.

Shortly after Congress immortalized the eagle on the Great Seal of the United States, Franklin shared his disappointment and misgivings over their choice in a letter to his daughter. Given the sparse pelt on his own pate, one might expect ol’ Ben would view the bald eagle as a kindred spirit, or at least harbor a bit of sympathy. Instead, his criticism was as harsh as any doled out by Simon Cowell, describing our new national symbol as “a Bird of bad moral character” who “does not get his Living honestly,” preferring to sup on rotting fish or, worse yet, stealing fresh seafood from more industrious raptors like the osprey (Pandion haliaetus). What’s more, Ben argued the eagle is cowardly, evidenced by how easily it can be driven away by much smaller birds defending their nests and offspring. Not exactly the role model image our fledgling country hoped to cultivate.

The turkey, according to Franklin, is “in Comparison a much more respectable bird,” a “true original Native of America” and a “Bird of Courage” who “would not hesitate to attack” any invader and defend his home turf.

This description might not square with your expectations after years of holiday stories featuring dim-witted, less than inspiring  Butterballs-to-be but the domestic turkey is but a pale and passive imitation of the real-deal.

Wild tom turkeys (as the males are called) will most definitely defend their breeding territory against potential rivals. Large and heavy, they are unexpectedly agile flyers, aggressive fighters, social, sometimes playful, intelligent, and adaptive.  To my knowledge they’ve never been accused of theft or caught dining on carrion (their omnivorous diet consists primarily of acorns and other nuts, seeds, fruit, buds and leaves, insects and the occasional small reptile or amphibian).

As far as moral character goes… well, you know rock stars. Toms strut their stuff in a flamboyant palette of iridescent red, green, purple, copper, bronze, and gold feathers worthy of Adam Lambert. No piercings or tattoos, but oozing cool with a Beat-worthy statement beard of stiff bristles starting just above the wishbone, wattles (flesh hanging from the head and/or neck), caruncles (fleshy growths on the head), snoods (long fleshy object draped across a tom’s beak), spurs and other body art. Their ladies, in keeping with general avian fashion trends, tend to be more conservatively dressed but they can strut like a runway model  when warranted, complete with long legs and outlandish makeup. Out of the spotlight, turkey hens are attentive mothers to their precocial offspring, in contrast to the menfolk, who are polygamous absentee fathers.

(Male bald eagles, it must be said, are actively involved in their children’s upbringing; given his own reputation, Ben might have been well served to heed the old saying about people who live in glass houses before he cast the first stone.)

Like the bald eagle, wild turkeys experienced a perilous decline in their numbers during in the last century, due to overhunting and habitat loss (rather than DDT exposure, as was the case for so many of our birds of prey).  Game agencies took action to protect the species and have been successful in helping the population rebound. So much so, in fact, that turkeys have not only returned to rural fields, pastures, and woodlands but have begun to tour in many major metropolitan areas as well.  In some parts of the country spotting a flock of wild turkeys foraging near a highway, hanging out downtown, or feasting at a backyard bird feeder is no longer a novelty.

That means a growing number of Americans now have a ticket to see  this national treasure up close and personal more than once a year, and at venues other than a serving platter.

For that, I am thankful.

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love-earthThis blog, like so many activities that foster support and appreciation of the natural world, is a labor of love. If you’ve enjoyed learning about the creatures who share our built environment, consider becoming an NDN Benefactor with a donation of any amount you’re inspired to give. If you’d like to find a little Next-Door Nature surprise in your inbox just click the Subscribe!  button in the upper right-hand corner of this page and receive notifications of new posts!

© 2012 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work. Just ask first.). Thanks to these photographers for making their work available through a Creative Commons license: Teddy Llovet (cover); keeva999 (turkey in flight); Mic Stolz (plumage); Peter Patau (men).

Size matters

Next-Door Nature, toucan, song sparrow, beak size

When you’re trying to stay cool without air conditioning, it helps to carry a radiator on your face, large or small (Photos: Ame Otoko and Cephas, Creative Commons license).

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A scientists’ work is never done.

That’s because there’s always another layer to peel away, another stone to turn, another angle from which to view the situation.  Case in point—nearly 200 years ago, Charles Darwin made the connection between the size and shape of a finch’s beak and the availability of the seeds they eat; to this very day, no one has been able to produce evidence that undermines his observation and the conclusions he drew from them.

But what if there’s more to a beak than meets the eye?

That’s the question raised by Russell Greenberg of the Smithsonian Conservation Biology Institute. His theory—that beak size may also be an adaptation to temperature regulation and water conservation—has been bolstered by data from two recently published studies.  [Data collected, in part, by a newly minted PhD named Ray Danner. Ray just happens to be a member of my own adopted extended family, and if that name sounds vaguely familiar… well, regular NDN readers may remember that not too long ago I was bragging about another member of this ornithological power couple, Ray’s wife, Dr. Julie Danner.]

black-tailed jackrabbitSome years back, Greenberg noticed a difference in size between the beaks of sparrows living in salt marshes and those of sparrows settled just a kilometer or two further inland. Then a paper published in 2009 reported toco toucans (Ramphastos toco) may lose as much as 60% of their body heat through their long bills, based on thermal imaging and similar to the role played by the large ears of both elephants (Elephantidae) and jackrabbits (Lepus spp.). While many ecologists assumed toucans were a special case, Greenberg wondered—might other birds have evolved larger or smaller beaks to discharge or conserve heat as well?

He chose to test his hypothesis by applying thermal imaging to a subject with a much less prominent proboscis—the song sparrow (Melospiza melodia).  Native to North America, everything about these feathered minstrels is miniature compared to their South American kin. The toucan weighs in at 1-2 pounds (the large bill doesn’t actually tip the scale as much as you might think since it’s mostly hollow) while at 0.4—1.9 ounces the song sparrow is definitely a featherweight.

In the first study, two subspecies were examined. On average, the beak of an Atlantic song sparrow was found to have 17% more surface area than that of the eastern song sparrow, although both birds have similarly sized bodies. Based on the Greenberg team’s calculations, the Atlantic sparrow loses 33% more heat than it’s inland neighbor. The finding suggests beaks may play a role in thermoregulation for a wide variety of bird species.

The ability to stay cool when the ambient temperature rises is critical to survival, but how one gets rid of the excess heat is just as important.  Birds don’t sweat—they pant… and lose not just heat but water in the process. This summer, residents across the U.S. have been reminded just what a precious resource water can be, and never more so than for all the creatures without easy access to a faucet.  Greenberg and his colleagues suggest that a bird’s beak can function like a radiator, releasing heat without losing water. The Atlantic sparrow’s larger bill saves the bird about 8% more water than the smaller beaked eastern sparrow. That may not sound like much but during a hot, dry summer it could be a significant survival advantage.

The second study examined museum specimens of song sparrows collected on the other side of the continent, along the California coast. Sure enough, as maximum temperatures increase, so did beak size… with one caveat.  When the maximum temperature was higher than 98°F (37°C) beaks got smaller… just as was predicted by the original hypothesis. You see, if you took a song sparrow’s temperature the thermometer would read about 105°F (41°C). When the air temperature exceeds the bird’s own temperature, as it does in some regions, a larger beak could actually begin to absorb heat.

While the Smithsonian group has demonstrated a connection between climate and beak size, there’s still plenty of work to be done. For the new hypothesis to garner support, scientists need to see data that ties survival of wild birds to beak size-related heat dissipation.

Meanwhile, the fact that diet influences beak size and shape hasn’t changed—Darwin can continue to rest in peace. But as so often is the case, the more we discover the more we realize just how rich and complex this world and its inhabitants are … even an Earthling as seemingly plain and simple as a sparrow.

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love-earthThis blog, like so many activities that foster support and appreciation of the natural world, is a labor of love. If you’ve enjoyed learning about the creatures who share our built environment, consider becoming an NDN Benefactor with a donation of any amount you’re inspired to give. If you’d like to find a little Next-Door Nature surprise in your inbox just click the Subscribe!  button in the upper right-hand corner of this page and receive notifications of new posts!

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© 2012 Next-Door Nature—no reprints without written permission from the author (I’d love for you to share my work; all you have to do is ask). Thanks to these photographers for making their work available through a Creative Commons license: [from the top] Ame Otoko (toco toucan); Cephas (song sparrow); James Marvin Phelps (black-tailed jackrabbit); Mr. T in DC (house sparrow on drinking fountain); David Craig (song sparrow in hand).