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Archive for the ‘Habitat’ Category

next-door nature, urban wildlife, suburban wildlife, barn swallows

The barn swallow is a spectacular aerial acrobat (Photo: Eugene Beckes, Creative Commons license)

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WITNESS astounding tricks of precision flying!

THRILL to the sight of daring aerial capers!

Come one, come ALL!

The FLYING CIRCUS is winging its way to a backyard near YOU!!

 

next-door nature, urban wildlife, suburban wildlife, barn swallowCritics are raving about this summer’s must-see event. Word to the wise, though—in addition to a lawn chair you’ll definitely want to bring some binoculars. That’s because the stars of this air show have an average wingspan of about 12 inches (30 cm). We’re not talking F/A-18 Hornets here, or even a Cessna 152. Think sparrow-sized, not Sparrowhawk.

Barn swallows (Hirundo rustica) epitomize the principle of “form follows function.” Combine a slender fuselage with long, tapered wings and a deeply forked stabilizer (aka “tail”) and you’ve got a bird made to spend the majority of waking life with wheels up. They even wear a uniform appropriate for fly-boys (and girls)—glossy chrome blue above and buff-to-rust below; similar to the colors of a U.S. Air Force Blue Angels jet.

Barn swallows are found far beyond U.S. borders, though.  You might even go so far as to call them jet setters. Six officially recognized subspecies are found in North and South America, Europe, Africa, and Asia. Generally speaking, the species breeds in the Northern Hemisphere (as far north as the Arctic Circle) and takes winter R&R in the Southern Hemisphere. Ornithologists have recorded barn swallows traveling over 7,000 miles (11,000 km) from Europe to southern Africa, and those based in the Americas cover similar distances.

next-door nature, urban wildlife, suburban wildlife, barn swallowWhether cruising inches above land or water or performing barrel rolls, loop-the-loops, spins, and stalls in mid-air, these agile flyers are crowd-pleasers. They aren’t grandstanding, though. A barn swallow’s life consists of more than playing with the physics of flight. Like the post-WWI stunt pilots of the 1920s, they’re trying to make a living.

It takes fuel to fly and the barn swallow go-juice of choice is winged insects—primarily high-octane flies, but also beetles, bees and wasps, next-door nature, urban wildlife, suburban wildlife, barn swallowmoths and butterflies, ants and termites.  Eating on the fly really comes in handy during long missions, including migration. Quenching one’s thirst, bathing, dating, and defending the home territory—they’re all done on the wing.

Historians disagree as to the origin of the term “barnstorming,” but one popular explanation is that pilots would fly through an open barn door and out the other side (they hoped) as a demonstration of their prowess and to drum up joy ride business.  Barn swallows have been known to fly in and out of barns as well—hence the common name. It’s a lot less risky for the birds, though.

Even daredevils like to have a place to call home, a chance to raise a family.  Before permanent man-made structures became commonplace, barn swallows built nests in caves or on the face of cliffs. Long tolerated by humans for reasons  both practical and aesthetic, today only one North American population holds to this tradition, in the Channel Islands off the coast of California; the rest of the fleet hangar in the rafters of open buildings or beneath porches. Bridges, especially those that span water, are particularly popular due to their proximity to crucial building materials.

next-door nature, urban wildlife, suburban wildlife, barn swallowGathering mud by the bill-full, mated pairs make countless supply runs to construct a neat cup or half-cup, depending on the location, then line it with grass, feathers, hair from the livestock living under the same roof, and any other soft, insulating materials they can find.

Once there’s a home base in the crosshairs, the bombardier gets the go-ahead to drop her payload of 3-7 eggs. The pair begin a series of aerial fueling attempts and in about a month’s time they’ve got themself a squadron of next-gen aviators.

Time to put on a show!

next-door nature, urban wildlife, suburban wildlife, barn swallow
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Barn swallows in flight:

Modern day barnstormer performing aerial acrobatics:

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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] Eugene Beckes (wings tucked; wings open); Julio Mulero (drinking); Dan Wilson Photography (nestlings); Eugene Beckes (swooping); Bill Lynch (muckraking); Mikael Dusenne (parenting); Pat Gaines (missile).

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Mexican free-tailed bat

Bracken Cave, in the Texas Hill Country, is home to the world’s largest colony of Mexican free-tailed bats. (Photo: © Merlin D. Tuttle, Bat Conservation International, http://www.batcon.org. Used with permission)

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When Doppler radar first arrived in the area known affectionately to Texans as The Hill Country, local television station meteorologists were understandably eager to show off the weather forecasting capabilities of their newest toy. Unfortunately, they got off to a less than impressive start. Night after night that summer, evening thunderstorms were forecast but failed to appear. This created distrust within the populace and confusion among the weather men and women. Eventually, someone figured out that Doppler couldn’t tell the difference between a microwave reflected by water droplets in the atmosphere and Mexican free-tailed bats (Tadarida brasiliensis) emerging from nearby Bracken Cave.

How many bats does it take to confuse Doppler radar? About 20 million.

Hundreds of Austin residents and visitors gather at the Congress Avenue Bridge every summer night to observe 1.5 million bats emerging to feed (Photo: © Merlin D. Tuttle, Bat Conservation International, http://www.batcon.org. Used with permission)

Several times in my life, I’ve had the privilege of watching, with barely contained glee, as Austin’s famous Congress Avenue bats poured out of the expansion slots below the bridge deck. With 1.5 million bats in residence, the city is home to the world’s largest urban bat colony. But the Bracken Cave colony dwarfs its city neighbor. It’s the world’s biggest, as well as the greatest known concentration of non-human mammals. Modern Americans will never have a chance to witness hordes of bison churning up the prairie or enormous flocks of passenger pigeons darkening the skies, but Bracken Cave—where it takes 4 hours for all the adult bats to stream out of the cave mouth and drift like smoke over Texas to feed—evokes some sense of what has been lost.

While in Austin a couple of years ago to attend the International Urban Wildlife Management Conference, I finally realized a long-time dream to witness this event with my own eyes. I was not disappointed. Bat Conservation International (BCI) owns the cave and the 697-acre buffer zone that keeps development at bay. The organization, which limits the number of visitors, graciously agreed to lead a group of conference attendees to the property, located near San Antonio.

During a brief orientation we learned that Bracken Cave bats migrate to Texas each spring from their winter home in Mexico, a distance of approximately 1,000 miles. The roof of the cave collapsed at some point in history, forming a perfect amphitheater from which to view the resulting entrance. Members of our group settled in twos and threes to watch, using small boulders as chairs and loveseats while we waited for the day to end and the main event to begin.

Bracken Cave is a maternal colony—no men allowed in this sorority—and soon after the females arrive, each gives birth to a single pup. Mexican free-tailed bat babies are not raised as only children; their mothers park them in a communal nursery set apart from where the adults hang out during the day. With as many as 500 babies per square foot of cave wall, the naked infants generate enough warmth to keep themselves cozy, freeing their mothers to leave each evening to cruise for calories. The downside of this arrangement? When it’s time to feed the offspring, Mom has to find her child somewhere in the mob—a task most human parents would find daunting.

The cave is not a home people would consider sweet. Millions of bats digesting millions of insects from March through October results in an annual deposition of 85 to 100 tons of bat feces, known as guano, on the cave floor. Experts estimate the guano may be 70 feet deep at the very back of the cave (and how one becomes an expert at estimating guano depth is beyond my ability, or desire, to imagine). As part of its stewardship of the site, BCI schedules periodic off-season “mining” of the guano—a practice that goes back to the late 1800s—which is currently sold as organic fertilizer.

As you approach the cave from a staging area near the property entrance, the distinctive, acrid smell of bat waste is hard to miss. Consider, if you dare, what it’s like underground. In winter, when the gals head south of the border to hook up with the guys and have the bat equivalent of a “Girls Gone Wild” experience, the cave is a comfortable 68°F; during the summer months, heat generated by all those bat bodies brings the ambient temperature inside to 108°F. Dermestid beetles are so abundant the floor writhes. The beetles feed primarily on guano, but any infant or injured bat who has the bad luck of falling is swarmed and consumed in minutes. Ammonia gas, a by-product of beetle digestion, fills the cave; levels inside are high enough to be fatal to humans so researchers must wear breathing apparatus to enter when the bats are there.

Personally, this is not the kind of place I’d choose to spend the summer. I lived in Texas for nearly 20 years and I have to say, the heat, humidity, and insect life above ground in July and August is as close to hell as I care to experience.*

Thankfully, during our field trip the air outside the cave was much more refreshing. It was a beautiful, clear, and blessedly temperate May evening, and before too long we began to see movement near the mouth of the cave. This show featured aerial acrobatics that would be the envy of any Blue Angel pilot. Bats were climbing, diving, banking, and stalling, making literally hundreds of mid-course corrections to avoiding collisions, while also attempting to evade the grasping hands of raccoons that gather near the mouth of the cave and the sharp talons of hawks circling above. It’s a dizzying scene, and the bats are both predator and prey.

What began as a small shower of bats quickly turned into a storm, with thousands of leathery wings mimicking the sound of a downpour. As their numbers continued to grow, they swirled and pulsed like a tornado, spinning in seemingly endless circles within the bowl of the sinkhole. Only after I raised my eyes from the dervish before me did I see a dark, smoky trail of bats stretching off beyond the horizon. And still the deluge continued all around us… bats, and more bats, and still more bats.

If, as Doppler radar would have us believe, bats are indistinguishable from raindrops, I’d have been drenched. And singin’, just singin’, in the rain.

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NOTE: Why are these bats called “free-tailed”? Because, unlike many species, the tail is not completely surrounded by a membrane, known at the patagium, that stretches between the animals’ legs—its at least partially “free” (see illustration below). The patagium also stretches between the fingers and connects the front and rear limbs to form the wing.

bat tails

Mexican free-tailed bat (left) and a Townsend’s big-eared bat (right)

*ok, I’ll confess to some hyperbole for the sake of the story. I actually enjoyed living in Texas, although less so during the summer.

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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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© 2011 Next-Door Nature— no reprints without written permission from the author. Thanks to Bat Conservation International for granting permission to use their photos. The drawings used above are open-source content.

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gray catbird

Once it begins to sing, any mystery about the source of the catbird’s name is solved (Photo: by Jerry Oldenettel, Creative Commons license)

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Because the semester was winding down, I wasn’t all that surprised to hear a soft, kittenish mewing coming from the small wedge of remnant wooded habitat between my apartment parking lot and the highway. I used to live in a complex near the Virginia Tech campus and, sadly, it’s common for a new crop of outdoor cats to appear as the students disappear. This is not unique to any particular school—it happens in college communities all across the country. People often believe cats are more independent and able to live on their own than dogs… that misperception may have something to do with the lack of guilt they seem to feel over abandoning their once-beloved pet.

But as I scanned the underbrush looking for the source, thinking of what I might use to coax a frightened feline to come out, come out, wherever it was, I came to the happy realization that I wouldn’t be making a trip to the animal shelter after all. It had been a long time since I’d heard a gray catbird (Dumetella carolinensis), and never was I more thrilled by a tune in the trees than on that Sunday morning.

Their call may be the world’s easiest to recognize. Once you’ve heard that “meow,” you won’t wonder another minute how the catbird caught its moniker. Like their relatives, the  mockingbirds and thrashers, these birds are able to copy other sounds and string them together to create a clever mash-up. But their signature song isn’t a case of mimicry—its all their own, shared by every member of the species.

Once my ears were retuned, I heard catbirds calling all over town—another reason to be happy, because this species, which is pretty common in most of its range, has been in decline recently in the southeastern U.S. You’d never know it in Blacksburg, though, where it can sound as though litters of catbirds have been turned loose in the woods.

If not for that distinctive call, you might not even notice these secretive birds. They don’t like to cross open areas so they stick to the thickets, moving in quick hops and short flights through dense vegetation as they search for insects and berries. At first glance, a catbird’s plumage is unremarkable. But look again and you’ll see that slate gray gives way to a jaunty black cap and tail. Look even more closely and you’ll see a rich rusty-orange patch just beneath the tail. That bright flash of pigment always takes me by surprise and makes me laugh—it’s like catching a glimpse of a colorful thong or boxers peeking out of a staid gray flannel suit!

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An example of the gray catbird’s diverse playlist — the first “meow” call is at about the 13 second mark.

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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.

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male american goldfinch

A male American goldfinch glows in sunshine or shadow (Photo: Dale Kaskey, Creative Commons license)

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There’s been a marked decline in the number of sunspots over the past decade or so. That’s what NASA scientists say, and I have no reason to doubt their research findings. Luckily, I haven’t observed any reduction in the terrestrial version of this phenomenon. Hardly a day has passed lately when I’ve not been blinded by the solar flare of a male American goldfinch (Carduelis tristis) as it escapes, briefly, the gravitational pull of a remnant patch of forest.

Actually, woodlots have a fairly loose grip on goldfinches, and they regularly venture out beyond the edge. It’s just that the male’s lemon-colored plumage glows against the inky green shade of conifers and summer hardwood foliage, or a cornflower blue sky, making them even more eye-catching than when the backdrop is amber waves of grain… or weedy native grasses. The undulating flight pattern only adds to the illusion of a plasma flash.

Found throughout the majority of North America for at least part of the year, and in about a third of the continent year-round, these smallish (4-5”) birds are regular visitors to backyards. In fact, suburban sprawl, which has proven so harmful to many wild species—neotropical migrant birds in particular—has been a boon for these devoted granivores. Goldfinches flock to places where thistle, sunflower, dandelion, cosmos, and aster seeds can be found, and development creates the perfect habitat for them and their favorite foods. The popularity of bird feeders hasn’t hurt either, since they provide seed-eaters with a competitive edge over birds that prefer other dining plans.

female american goldfinchAlso known as the wild canary, this species is sexually dimorphic, meaning gender can be distinguished by some physical feature—in this case, plumage. As is so often the case among wild birds, the female American goldfinch’s wardrobe is understated compared to her mate. The sunny palette is still present, but her hue of choice is a dull or olive-tinged yellow, and her wings are a shade or two lighter although similarly marked.

Boy or girl, the gold in those feathers comes from carotenoid pigments in their diet. It’s the same process and components that causes flamingo (Phoenicopterus and Phoenicoparrus spp.) feathers to be pink, coral or orange (the wild ones get their color from the red algae and aquatic invertebrates they consume, while captive birds rely on fortified flamingo chow). Without carotenoids in their diet, flamingos would become a much paler version of the iconic plastic subspecies, and goldfinches would go from 24 to 10 karat.

You are what you eat, you know. So are goldfinches. And even though it’s converted into an amazing variety of forms—thistle seeds, bluegrass, brussel sprouts, mangos, caviar, cheese, chicken chests, and hamburgers—when you get down to basics, we’re all eating sunshine. It just shines more brightly through some of us than others.

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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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© 2011 Next-Door Nature— no reprints without written permission from the author (I’d love for you to share my work but please ask first). Thanks to Arthur Chapman for making his photo of a female American goldfinch clinging to a feeder available through a Creative Commons license.

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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).

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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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There’s nothing quite like finding a little Next-Door Nature in your email inbox—click the “subscribe”  link 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: [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).

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next-door nature, urban wildlife, suburban wildlife, barn swallows

The barn swallow is a spectacular aerial acrobat (Photo: Eugene Beckes, Creative Commons license)

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WITNESS astounding tricks of precision flying!

THRILL to the sight of daring aerial capers!

Come one, come ALL!

The Flying Circus is winging its way to a backyard near YOU!!

 

next-door nature, urban wildlife, suburban wildlife, barn swallowCritics are raving about this summer’s must-see event. Word to the wise, though—in addition to a lawn chair you’ll definitely want to bring some binoculars. That’s because the stars of this air show have an average wingspan of about 12 inches (30 cm). We’re not talking F/A-18 Hornets here, or even a Cessna 152. Think sparrow-sized, not Sparrowhawk.

Barn swallows (Hirundo rustica) epitomize the principle of “form follows function.” Combine a slender fuselage with long, tapered wings and a deeply forked stabilizer (aka “tail”) and you’ve got a bird made to spend the majority of waking life with wheels up. They even wear a uniform appropriate for fly-boys (and girls)—glossy chrome blue above and buff-to-rust below; similar to the colors of a U.S. Air Force Blue Angels jet.

Barn swallows are found far beyond U.S. borders, though.  You might even go so far as to call them jet setters. Six officially recognized subspecies are found in North and South America, Europe, Africa, and Asia. Generally speaking, the species breeds in the Northern Hemisphere (as far north as the Arctic Circle) and takes winter R&R in the Southern Hemisphere. Ornithologists have recorded barn swallows traveling over 7,000 miles (11,000 km) from Europe to southern Africa, and those based in the Americas cover similar distances.

next-door nature, urban wildlife, suburban wildlife, barn swallowWhether cruising inches above land or water or performing barrel rolls, loop-the-loops, spins, and stalls in mid-air, these agile flyers are crowd-pleasers. They aren’t grandstanding, though. A barn swallow’s life consists of more than playing with the physics of flight. Like the post-WWI stunt pilots of the 1920s, they’re trying to make a living.

It takes fuel to fly and the barn swallow go-juice of choice is winged insects—primarily high-octane flies, but also beetles, bees and wasps, next-door nature, urban wildlife, suburban wildlife, barn swallowmoths and butterflies, ants and termites.  Eating on the fly really comes in handy during long missions, including migration. Quenching one’s thirst, bathing, dating, and defending the home territory—they’re all done on the wing.

Historians disagree as to the origin of the term “barnstorming,” but one popular explanation is that pilots would fly through an open barn door and out the other side (they hoped) as a demonstration of their prowess and to drum up joy ride business.  Barn swallows have been known to fly in and out of barns as well—hence the common name. It’s a lot less risky for the birds, though.

Even daredevils like to have a place to call home, a chance to raise a family.  Before permanent man-made structures became commonplace, barn swallows built nests in caves or on the face of cliffs. Long tolerated by humans for reasons  both practical and aesthetic, today only one North American population holds to this tradition, in the Channel Islands off the coast of California; the rest of the fleet hangar in the rafters of open buildings or beneath porches. Bridges, especially those that span water, are particularly popular due to their proximity to crucial building materials.

next-door nature, urban wildlife, suburban wildlife, barn swallowGathering mud by the bill-full, mated pairs make countless supply runs to construct a neat cup or half-cup, depending on the location, then line it with grass, feathers, hair from the livestock living under the same roof, and any other soft, insulating materials they can find.

Once there’s a home base in the crosshairs, the bombardier gets the go-ahead to drop her payload of 3-7 eggs. The pair begin a series of aerial fueling attempts and in about a month’s time they’ve got themself a squadron of next-gen aviators.

Time to put on a show!

next-door nature, urban wildlife, suburban wildlife, barn swallow
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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] Eugene Beckes (wings tucked; wings open); Julio Mulero (drinking); Dan Wilson Photography (nestlings); Eugene Beckes (swooping); Bill Lynch (muckraking); Mikael Dusenne (parenting); Pat Gaines (missile).
Barn swallows in flight:
Modern day barnstormer performing aerial acrobatics:

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