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.]

Summer Soundtrack

The eastern gray treefrog is one of many performers in nightly summer concerts.

The eastern gray treefrog is one of many performers at nightly summer concerts.

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One of my favorite things about summer is the free outdoor concerts. I’m not talking about local bands that occasionally perform from the park gazebo even though they can be a pleasant accompaniment to my evening dog walk. No, nothing says summer like the insect-amphibian jam sessions that take place almost every evening.
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I’ve moved quite a lot in my life and have been delighted to learn that each place I’ve lived long enough to grow accustomed to—six U.S. states and a Scandinavian country—has a timbre and cadence all its own, distinctive to that specific habitat in a certain continent on a singular planet in an expanding universe. It’s the soundtrack of home, wherever home may be at that particular time in field cricket 2 by Jimmy Smith, CCLone’s life.
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The musicians start warming up as the light begins to fade. They’ve been playing the same basic tune since I was a child so I immediately recognize the overture. By 7:00-7:30p the instruments are tuned and ready to swing.
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Field crickets (Gryllus spp.) establish the beat with their forewings, kind of like a finger-snap that varies from cool to hot depending on the atmosphere.
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Common true katydids (Pterophylla camellifolia) shift the accent…
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common meadow katydid by Rachid H, CCL… and the common meadow katydids (Orchelimum vulgare, not as common as the name implies) chime in with a bit of lawn-sprinkler syncopation.

 [you might need to boost the volume a bit on this one]

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Before long, the dog-day cicadas (Tibicen canicularis) are stealing the show.
dog-day cicada by Roger Engberg, CCL
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As the evening progresses, though, the cicadas and other insects cede the stage to the second act—the frogs and toads… possibly because these headliners have been known to devour the opening act!
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The band is made up primarily of horns and percussion. This isn’t jazz—there’s not much in the way of improvisation and the musicians don’t really take turns letting one another shine during a solo. It can be difficult to identify the featured players, in part because the cast keeps changing; there are fair-weather performers, some northern cricket frog by Andy Reago and Chrissy McClarren, CCLhave stormy temperament, and others don’t like to travel far from their favorite watering hole. Still, there are some easily recognized voices.
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Northern cricket frogs (Acris crepitant) step in to set the pace abandoned by their namesake insect. I’ve seen their call described as pebbles bouncing against one another but to me it’s a metal cabana—chain wrapped around a wood cylinder and shaken, not stirred.
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The American toad (Anaxyrus americanus) is a minimalist; not much complexity but the sustain on that single trilling note is impressive.
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green frog by Matt Reinbold, CCLThe green frog (Lithobates clamitans), on the other hand, is a true traditionalist—no electric bass for this fellow, or even an upright acoustic. Listen carefully and you’ll hear his homage to a single string and washtub.
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Tiny boreal chorus frogs (Pseudacris maculata) play plastic comb call-and-response…
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eastern gray treefrog by USFWSmidwest, CCL… and the gray treefrogs (Hyla versicolor) are in charge of the upper register. These little guys can blow, plus how about that vibrato!
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When the gang’s all here and lettin’ it rip the result is more cacophony than symphony—not everyone’s ideal night music but a lullaby to my ears.
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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). Thanks to these photographers for making their work available through a Creative Commons license (CCL) or Project Guttenberg License (PGL) (from top to bottom):  USFWSmidwest (eastern gray treefrog); Jimmy Smith (field cricket); Lisa Brown (common true katydid); Rachid H (common meadow katydid); Roger Engberg (dog-day cicada); Andy Reago & Chrissy McClarren (northern cricket frog); AllieKF (American toad); Matt Reinbold (green frog); J. N. Stuart (boreal chorus frog); USFWSmidwest (eastern gray treefrog). 

Comeback

The great egret has made a spectacular comeback from near extinction.

The great egret has made a spectacular comeback from near extinction.

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Heat and Humidity have resumed their annual one-upmanship contest here in Arch City. Being outdoors mid-day can be unpleasant, so my canine companion and I have been trying to beat them to the starting blocks by heading out for our daily constitutional as early as possible.
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lafayette square row houses by paul sableman, cclWe stroll two blocks, past grand Italianate manors and restored Victorian row houses, to a handsome mid-19th century city park—the oldest in the Louisiana Purchase Territory. Paved pathways meander through 30 acres of enormous shade trees and lovingly tended flower beds, past fountains, a graceful bridge, and a gazebo, all within the protective embrace of the original cast iron perimeter fence.  There’s even a lake, complete with fish, semi-aquatic turtles, a small flotilla of Canada geese (Branta canadensis), mallards (Anas platyrhynchos), and a scattering of former Easter ducklings. And what Victorian-era water-feature would be complete without a few imperious mute swans (Cygnus color)?
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The park is a hub of activity in afternoon and early evening. The sound of vehicles, emergency sirens, construction and commerce seep in from the surrounding streets, combining with the squeals of children blowing off steam at the playground,  flag football players shouting audibles, or a crowd cheering at vintage baseball game, depending on the season. Fiercely determined joggers make their appointed rounds. Dogs check messages on trees and bushes while their humans check smartphones. Families gather ’round a grill, young lovers picnic on hand-me-down quilts, wedding rings are exchanged, friends play frisbee, and there’s even the occasional free open-air concert or movie night under the stars.
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lafayette park garden path by John, CCLMost mornings, though, it feels like a quiet private garden. The park has become a favorite since my homecoming a couple years ago. GPS may pin my location as near the center of a bustling city but the dappled stillness of this urban oasis, complimented with the music of dancing water and splashes of birdsong, sets an unhurried tone. By the end of our walk I’m ready to step off of cobblestones onto the Information Highway and into my 21st century life.
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great egret by VisitCentralFL, CCLDuring a recent dawn stroll around the lake, I spotted a slim solitary figure standing still as a statue at the water’s concrete edge; a great egret (Ardea alba Linnaeus) doesn’t exactly blend in with the surroundings. There’s simply no point in trying when you’re a 3’ tall bird with a serpentine neck, clad in your breeding season best: extravagant lacy white plumes, a saffron bill, lime-green lores, and long jet-black legs and feet.
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My heart leapt—not because the bird was beautiful (although it was), and not because I didn’t yet have one on my life list (I’ve seen many). No, it was seeing a great egret in this place that brought tears of joy to my eyes.
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bird hat - public domainWhen Lafayette Park was first dedicated, it would have been a rare sight indeed to see those elegant courtship aigrettes on anything other than a lady’s hat.  Great egrets were hunted almost to the point of extinction to satisfy fashion’s dictate that a proper, self-respecting adult female must never be seen in public without a pile of millinery fabric, lace, ribbons, flowers, feathers, and bird body parts balanced on her head. Egret plumes, in particular, were all the rage.
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Concern over the looming disappearance of this and other bird species allowed a fledgling U.S. conservation movement to take flight in the early 20th century.  By 1918, the National Audubon Society and others successfully pressured Congress into passing and funding the Migratory Bird Treaty Act. It was our first serious wildlife protection legislation, and by any measure the Act has been a spectacular success. Many species on the verge of extinction 100 years ago are now doing quite well.  And while hats and “fascinators” are currently experiencing a small uptick in popularity after a decades-long fall from favor, albeit without the wild bird feathers that graced predecessors, their numbers pale in comparison to the great egret renaissance. Although exact population numbers are hard to find, the species is now classified as “common,” numbering in the tens of thousands of breeding pairs, at minimum.
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On this morning, though, it was just a solitary great egret, a noble wire fox terrier (Queen Victoria herself kept one as a pet), and me, the least pedigreed of the group, standing at the intersection of past, present, and future.
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great egret fishing by Alan Huett, CCLI spent a long moment contemplating the significance of a stately creature’s return, and my own, to this historic midwestern park, watching as the bird gazed intently into the water, meditating on the play of light and liquid.
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Or perhaps something both deeper and more practical. Like breakfast.
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Brought back to the here and now by a nudge from my own stomach, I turned toward home. But not before saying over my shoulder, “It was great to see you again—come back anytime!”
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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). Thanks to these photographers for making their work available through a Creative Commons license (from top to bottom): Helen Haden (white on black); Paul Sableman (Lafayette Square homes); John (Lafayette Park garden path); VisitCentralFL (strike a pose); Public Domain (woman wearing bird hat); and Alan Huett (fishing).

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

Damsels and dragons… but no prince

damsel fly at rest, Next-Door Nature, urban wildlife

This lanky damsel isn’t waiting for a charming champion to rescue her (or him?). It’s just resting up for another mosquito-shopping trip (Photo: Tomquah, Creative Commons license).

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Once upon a time there was a damsel(fly).

[Imagine, if you will, a bucolic Disneyesque soundtrack of flutes and piccolos in the background.]

She (Or maybe he. This is a modern fairly tale.) explored the lovely little pond from which s/he had recently emerged after having spent most of life underwater as a nymph.

Who would have guessed during that awkward adolescence, when growth spurts had him/her literally jumping out of her skin a dozen times or so, that she would transform from an ugly duckling into a swan? (Speaking of awkward… let’s just stick with “her” from here on out for the sake of simplicity, shall we?)

So… today was her debut. A coming out, of sorts, and the damsel(fly) flitted here and there, enjoying the warm sun shimmering and gleaming on her iridescent wings as she dipped down to the water now and again to daintily snack on mosquito larvae.

Not a care in the world.  Completely oblivious to…  [Cue the ominous bassoon music] …the looming presence of a dragon(fly) on the other shore.

Not that it mattered, really. [Can I have the flutes and piccolos back, please?]  Sure, the dragon(fly) was part of the Epiprocta clan, the damsel(fly) a Zygoptera, but they were both members of the Order Odonata. No family feuds that she knew of, and so closely related were they that many folks had trouble telling one from the other without assistance in the form of a handy reference table.

They were cousins, but not kissing cousins. No interspecies hanky-panky here, even though their kind were known as having an unusual approach to romance. You see, instead of offering a wake-up kiss, the male clasps the female behind her head with a special appendage on the tip of his abdomen. IF she welcomes the embrace, instead of sliding her foot into a size 6 glass Louboutin slipper eventually she loops her abdomen forward to pick up the spermatophore from a structure on his abdomen and deliver it to her spermatheca [Latin is a romance language, remember].

I know, I know… it sounds kind of weird and kinky but trust me, it’s just hard to describe. When it’s right it’s a beautiful thing, especially when the couple forms a kind of heart with their entwined bodies [Everyone say “awwwww”].

Sometimes they even become members of the Mile-High Club, flying united for a little while. But damsel(flies) and dragon(flies) aren’t the marrying kind. They’re independent and self-sufficient—a characteristic that begins in infancy. Good thing, too, because, to be perfectly honest, the adults are neglectful parents. Dad is no prince, zooming off with hardly a backward glance at the new Mom-to-be, who’s no queen of the nursery herself. She deposits her eggs in floating plants or directly into the water and then washes her (metaphorical) hands of the responsibilities of child-rearing.

The nymphs (aka naiads) hatch and, being carnivorous little monsters, begin feeding on mosquito larvae, daphnia, tadpoles, small fish, and sometimes each other.

That happens among adults as well, although the jury’s still out on the subject of postcoital cannibalism, a not-uncommon behavior in the insect world. It’s enough to give a girl pause (although, for most insect species it’s the guy who needs to worry about fatal attractions).

Whatever. This is the 21st century and females of every stripe and species are all about DIY.  Gals today don’t need a prince to save them. Locked up in a tower? Any modern, self-respecting damsel knows you simply pull out your smartphone, Google instructions for making a rope out of sheets, and then shimmy down to freedom.

Evil stepmother? Please. Dial the Child Abuse Hotline and tell that witch you’ll see her in court!

Face to face with a dragon? Reach for your trusty catch-pole or tranquilizer dart gun apps.

And live happily ever after.

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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: [starting from the top]: Tomquah (cover damselfly); Photo munki (nymph… not the same species); Clifton Beard (mating damselflies); Ben McLeod (dragonfly eyes); and Charles Lam (damselfly eyes).

Hot and cold

next-door nature, urban wildlife, fence lizard

Everyone, even fence lizards and other ectothermic creatures, are feeling the heat these days (Photo: Bandelier National Monument, Creative Commons license)

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Temperatures across the southern half of the U.S. are soaring into triple digits, so I was trying to think of creative solutions to beat the heat when it hit me—why not become cold-blooded!

next-door nature, urban wildlife, fox squirrelAlas, my brain must have overheated. Once air conditioning allowed a cooler head to prevail I realized that what seemed like a brilliant idea while baking beneath a blazing sun is absolutely, completely, utterly impossible… and not simply because mammals cannot will themselves to undergo metamorphosis.

You see, technically there’s no such thing as a cold-blooded animal (unless you’re speaking metaphorically about someone who lacks emotion or empathy).  Or a warm-blooded animal, for that matter. Both terms are shorthand for the ways in which body temperature (aka thermophysiology) is controlled in different types of organisms.

Most mammals and birds are classified as endotherms (Greek: endon = within; thermē = heat). For these critters thermoregulation is an inside job, primarily by way of metabolic processes. Under extreme environmental next-door nature, urban wildlife, sunbathersconditions some physical mechanisms come into play, but not solar energy (at least, not directly). If the mercury plummets and the body’s core temperature begins to drop, muscles shiver to create warmth; if the core temperature starts to rise the body perspires to cool via evaporation. No sweat glands? Pant like a dog… or birds. All evidence to the contrary, since humans are mammals, swimsuit-clad sunbathers dozing in rows on a beach or poolside with icy drinks standing at the ready are, in fact, capable of maintaining a relatively constant body temperature.

next-door nature, urban wildlife, gray treefrogWhen an animal’s body temperature is strongly influenced by ambient conditions it’s an ectotherm (Greek: ektós = outside). Fish, amphibians, reptiles, and invertebrates rely on external heat sources to get their juices flowing, especially during the chillier seasons or cooler times of day. That’s why these animals can be seen basking on rocks, roads, and any other warmth-radiating surface. Then, when they can’t stand the heat they get out of the kitchen, retreating into shade, water, or underground to cool off (Sound familiar? We really are more alike than different).

Take-home message: mammals and birds are endotherms; invertebrates, fish, amphibians, and reptiles are ectotherms.

Except when they aren’t.

It’s the exceptions that make the rule, right? Let’s begin with the usual ectotherm suspects. According to one source, 2% of invertebrates are endothermic. Regrettably, the informant failed to name names but, in spite of the fact that spineless animals are not my strong suit, I did managed to chased one down—snails and slugs (Oops, that’s two… and “chased” may be overstating things).  Fish, being vertebrate species, are my regular beat so I can state with certainty that billfish (e.g., sailfish, marlins), tuna (Scombridae), one family of sharks (Lamnidae, including makos and whites), and one species of mackerel (Gasterochisma melampus) are endothermic… at least to some degree. I’ve yet to find a reliable report of an endothermic amphibian, but among the reptiles sea turtles exhibit both ecto- and endothermic traits.

next-door nature, urban wildlife, echidnaMoving along to the endothermic exceptions… Hummingbirds (Trochilidae), swifts (Apodidae), and common poorwills (Phalaenoptilus nuttallii) all experience periods of lower body temperature and metabolic rate; therefore, some biologists argue they have ectothermic traits. Additionally, there are mammals—certain rodents, a couple of lemurs, and many bats—that enter hibernation or estivation in response to low temperatures or drought, respectively. Then there’s the echnidna (Tachyglossidae), a “primitive” mammal from Australia that’s an ectotherm eleven months of the year and an endotherm during the month when it lays its eggs (Yes, eggs. If you like rule-breakers Australia is your Mecca. In the interest of time and space, though, we’ll have to save monotremes for another day).

What I’ve presented above is a fairly simplistic description of thermophysiology.  Why stop there? Because a more thorough treatment would require a good deal of nuance and a complicated discussion of sub-categories, not to mention a stiff drink (the current temperature is 99°F and rising—make mine a frozen margarita).  But since it’s so hot I’ll go ahead and venture past a toe in the water… up to my knees, but no further.

next-door nature, urban wildlife, elephant shrewOne subset of the endotherms are tachymetabolic (Greek: tachy = quick), organisms with a consistent and extremely high metabolic rate. Shrews (Soricidae) are a perfect example—diminutive beings with massive appetites, their metabolic rate is at least five times that of similarly sized ectotherms. Being able to snack non-stop and still rock a bikini probably sounds too good to be true. It is. Finding a constant supply of calories without access to fast food and grocery stores is no picnic. Bradymetabolic (Greek: brady = slow), which could easily be mistaken for bipolar disorder, is no bed of roses either. These organisms swing wildly between a high (when active) and low (when resting) metabolism, usually based on either external temperatures or food availability. (If you think someone else has got it better, rest assured you probably don’t know the whole story.)

As biologists refine our understanding of how bodies work, language evolves and once popular terms like cold-blooded fall from favor. Popular stereotypes suggest otherwise, but scientists are not completely immune to trends. When I was an undergrad, for example, the preferred word for organisms influenced by changes in ambient temperature was poikilotherm (Greek: poikilo = varied, irregular). Although still useful for making distinctions between types of ecotherms, the term is used less frequently now and may be on it the way out.

next-door nature, urban wildlife, crocodilesC’est la vie. Styles change, in both the lab and on the beach (Thankfully. I’m old enough to remember when Speedos were all the rage in men’s swimwear). I’d be willing to bet, though, that most Earthlings won’t give up sun worship any time soon. Chillin’ in a sunbeam feels too good, whether you need it or not (at least as long as there’s a pool nearby).

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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. Just ask first.). Thanks to these photographers for making their work available through a Creative Commons license: Bandelier National Monument (sunning fence lizard); Michael V. Flores (fox squirrel cooling down); Nick Papakyriazis (sunbathers); geopungo (gray treefrog); BohemianDolls (elephant shrew); and Jess Loughborough (basking crocodiles).