Feeds:
Posts
Comments

Archive for the ‘Invertebrates’ Category

Sometimes green means stop, look, and pay attention.

.

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.
.
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.
.
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.
.
Until, suddenly, it was.
.
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.
.
Then I was blinded by the light of a sunbeam reflecting off an iridescent copper-green carapace.
.
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.
 .
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…
 .
and…
             slowed…
                                 waaaaay…
                                                          down.
.
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.
.
composite greens
.
.
red-orange-yellow composite
.
purple composite
.
bright composite
.
How easy it is to forget that being unproductive is sometimes the most important work of all.
.
.
.
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 — and please share this post with others!
.
© 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.

Read Full Post »

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.

.
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.
.
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.
.
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.
.
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.
.
Common true katydids (Pterophylla camellifolia) shift the accent…
.
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]

.
Before long, the dog-day cicadas (Tibicen canicularis) are stealing the show.
dog-day cicada by Roger Engberg, CCL
.
.
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!
.
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.
.
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.
.
The American toad (Anaxyrus americanus) is a minimalist; not much complexity but the sustain on that single trilling note is impressive.
.
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.
.
Tiny boreal chorus frogs (Pseudacris maculata) play plastic comb call-and-response…
.
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!
.
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.
.
 .
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!
.
© 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). 

Read Full Post »

Caption (Photo: OakleyOriginals 2008 Creative Commons license)

For this intrepid youngster, a cicada is good for a smile on a hot August day.

.

Kindergarteners swarmed around the khaki-clad naturalist, squealing with excitement, shouting out questions and jockeying for a better view. The adult volunteers on this field trip were a tougher audience.

“I’m glad they’re having fun but I don’t see why anyone should care about some bug,” one 30-something mom confided to another, adding, “What good is it, anyway?”

I overheard this question while visiting a nearby urban nature center but it’s just one variation on a theme I’ve heard throughout my life and career… a theme that opens the door to fascinating explorations of the ways human beings assign instrumental and intrinsic value to creatures great and small.  And I do so love engaging philosophical conversations.

My first, unfiltered instinct, however, is to hurl the question back at them like a boomerang: “What good are YOU?”

I catch myself—usually—before the words escape, gently reminding my outraged inner eco-warrior that choosing honey over vinegar improves our chances of winning both the battle and the war.

To successfully implement a honey-offensive, it helps to have an arsenal of sweet scientific research think-bombs at the ready. This is an arms race and, naturally, I’m always on the lookout for a chance to acquire the hottest new technology so I can blast misconceptions and prejudices to smithereens.

Imagine, if you will, my greedy glee when, last week, I stumbled on an amazing new trove of ammunition from a most unlikely source.

Theo's friend by Phlora 2007 CCLIs there a creature  more likely to inspire the value question than a cicada? (In those parts of the world where insects are not a significant source of protein in the human diet, that is.) How’s this for a life cycle? Hatch from your egg, drop out of your natal tree, dig in and spend 1—17 years (depending on your species) hanging out underground sipping root juice and metamorphosing through various awkward stages of puberty. Finally emerge from the soil, climb out of your skin one last time. Rest until your shiny new wings harden then hook up with a member of the opposite sex and get busy… or not. Depends on how long you can avoid being eaten by a squirrel, a bird, a dog or cat, a fish… and rest assured, you will be eaten at some point during those 1—6 weeks of halcyon summer days preceding your demise.  Unless you are transformed into a zombie slave by a cicada killer wasp (Exeirus lateritius) in need of a surrogate mother for its offspring, in which case you’ll still be eaten but it will take longer for you to die.

cicada killing wasp by Steve Krichten 2003 CCLOne could argue that if the nihilists are searching for a mascot, they need look no further than one of the 2,500   Cicadidae clan member species. Still, until the pointlessness of existence becomes a dominant meme in human culture even a potential poster-child gig is unlikely to satisfy a determined anthropocentrist who insists on asking, “What good is it? You know… for people?”

Turns out, Australia’s clanger cicada (Psaltoda claripennis, aka clear wing cicada) may end up doing quite a lot of good for people. Unintentionally, of course; insects aren’t known for their benevolence. But according to a recently published Biophysical Journal article cicadas may be an accidental ally in our battle against bacteria.

clanger cicada by Melanie Cook 2004 CCLChemical warfare is common in the insect world. Humans readily adopt the same strategy against both microscopic and macroscopic opponents (although, in most circles it’s considered verboten in human-versus-human conflicts). Funny thing about man-made poisons—they tend to deliver short-term success followed by long-term environmental headaches, especially when used against enemies with high reproduction rates. Insects and bacteria, for example. As a former defense secretary once said, though, you go to war with the army you have. We have chemicals. Lots of chemicals.

How refreshing, then, that according to a team of researchers from Australia and Spain, evolution has armed the clanger cicada with a vaguely medieval yet elegantly simple physical defense against infection.

Spikes.

Enough to make a punk rocker proud (and Vlad the Impaler SO  jealous). You see, clanger wings are covered in an array of sharply pointed nanopillars. When a hapless bacterium settles on this surface, it stretches and sags into the crevices between the spikes, like Jell-O on a bed of nails, until the cell membranes are shredded and the microbe is incapable of reproducing.

Scientists have already begun to investigate the potential of synthetic cicada-inspired materials. Think of it—in the not-too-distant future countertops, doorknobs, bus straps and subway poles, sinks and commodes, railings, surgical instruments and even money could be covered with a passive bacteria-killing surface that makes the ubiquitous hand-sanitizers obsolete!

Now, how could an invention like that possibly do a young mother any good?

.

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!

.

© 2013 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: OakleyOriginals (smiling face, 2008); Pholra (kitten, 2007); Steven Krichten (cicada killing wasp, 2003); Melanie Cook (clapper cicada, 2004)

Read Full Post »

arctic fox by emma j bishop cc

There’s nothing quite as contagious as a yawn* (Photo: Emma J. Bishop, Creative Commons license)

.

Grab forty winks. Saw logs. For a species that’s habitually short on shut-eye, we humans sure have come up with myriad ways to talk about it. We also spend a lot of time and money studying sleep, or the lack thereof. Yet, in spite of decades of inquiry, researchers still don’t have a good fix on why we—and just about every other living creature—need to nod off.  We’ve had better luck trying to understand other unconscious states, especially those employed by certain non-human species to deal with hard times.

yawning prairie dog by SearchNetMedia ccWinter poses a critical challenge for animals who stay put rather than migrate to warmer climes. Thermoregulation requires calories, but many foods—especially fruits, nectars, vegetation, and insects—are scarce when the days are short. The ability to reduce one’s energy needs can be a life-saving adaptation. Hibernation does just that—it lowers an animal’s metabolic rate. If all goes well, this period of inactivity, which may last several days, weeks, or even months, depending on the species, will stretch stored energy reserves (aka body fat) long enough for the animal to survive until a greener season. “If” depends on many factors, such as the abundance of autumn food resources, the length and severity of cold days, and even the stability of the den site during repeated freeze-thaw-freeze cycles.

When a critter—let’s use the chipmunk (Tamias spp.) as an example—transitions into a state of hibernation, its body temperature drops to near freezing, breathing becomes so shallow as to be imperceptible, and the heart rate decreases dramatically, from 350 to 4 beats per minute.  Although we tend to think of hibernation as a season-long slumber, chippies and other hibernating rodents do wake up every few weeks to have a snack and take a potty break, even though these periods of activity, called interbout arousals, consume up to 90% of stored body fat. There are some champion nappers in this chisel-toothed group—including the groundhog (aka woodchuck, Marmota monax), who sleeps half its life away, setting the alarm for March when it heads to bed in September.

Other examples of sound sleepers include: insectivores like the European hedgehog (Erinaceus europaeus) and the tenrecs (Microgale spp.); the mountain pygmy possum (Burramys parvus)—the only hibernating marsupial; and the echidna (Tachyglossus spp.), a monotreme.  Biologist recently added the mouse lemur (Microcebus spp.) and the fat-tailed dwarf lemur (Cheirogaleus medius) to the hibernator roster; prior to this discovery, we didn’t have any examples from among the primates. Additionally, since winter temperatures in their native Madagascar may reach 86° F (30° C), it’s become clear that hibernation isn’t strictly associated with cold weather. Nor is it limited to mammals; a bird called the common poorwill (Phalaenoptilus nuttallii) snoozes through at least some of the snowy season.

yawning polar bear by Paul Davidy ccIronically, that most famous of North American sleep icons, the bear (Ursus spp.), is the subject of many a drowsy debate over whether or not they are “true hibernators.” Bears often spend far more time sleeping than the so-called “trues,” so what’s all the fuss about?  Well, this is going to sound like nit-picking, but here goes. First of all, a bear’s heart rate drops, but not quickly enough to suit some scientists. Also, while the number of heartbeats may go as low as 8 per minute, the average is closer to 50 per minute. Moreover, during this time the bear’s body temperature remains pretty close to normal. This is a handy little idiosyncrasy that, should the need arise, allows the animal to wake up fast… and often cranky—a fact Santa (and anyone else) should keep in mind when planning a mid-winter visit to the den.

Taking to one’s bed for months on end could be seen as a rather over-the-top response to a simple cold front. It smacks of swooning characters in English romance novels from the late 1700s. Frankly, it’s not everyone’s cup of tea, and many wild critters take a more measured approach. Torpor is the term commonly used to describe these shorter, less dramatic forms of dormancy, although, technically, hibernation and other types of suspended animation are really subsets of torpidity. Call it what you will, there are examples of “temporary hibernation” in all the Classes of vertebrate animals—mammals, birds, reptiles, amphibians, and fish—and it’s commonplace among the myriad spineless critters as well.

For some of the busiest bodies, torpor is a daily habit. Hummingbirds (Trochilidae), for example, have such a high metabolic rate that they need to ingest a steady stream of non-carbonated sugar water (i.e., nectar) during their waking hours or they’ll become hypoglycemic and too exhausted to fly. Can’t fly? Can’t feed—a vicious circle that will ultimately lead to the bird’s death without some kind of intervention. As you might imagine, this need to constantly refuel creates an enormous problem when night falls and these feathered perpetual motion machines must rest. Without some way to temporarily lower their metabolic rate, hummingbirds would never be able to get out of bed in the morning. Never fear—torpidity to the rescue!

rock dove yawning by Tatiana Bulyonkova ccSwifts (Apodidae), chickadees (Paridae), nightjars (Caprimulgidae), and doves (Columbidae) are just a few of the other avian species who go torpid under various conditions. Generally speaking, these birds are fruit-, nectar-, or insect-eaters, and they tend to be on the small side (less than 80g). The snowy owl (Bubo scandiacus), at 1600-2950g is one exception to this rule, and biologists recently added a second, when it was confirmed that the tawny frogmouth (Podargus strigoides) goes torpid during Australian winters.

Personally, I find these new insights into animal behavior thrilling, because they reassure me that what we know about wild creatures is still a drop in the bucket compared to what we don’t know—there are worlds upon worlds waiting to be discovered on this blue gem of a planet we call home.

yawning turtle by Michael Ransburg ccOf course, cold is not the only hardship wild things would rather sleep through. Periods of drought are just as serious a threat to survival, especially for aquatic and semi-aquatic species. When a lake, pond, or stream goes dry, the inhabitants need to dig in. Literally. Turtles and tortoises (Testudines), crocodiles (Crocodylidae), frogs and toads (Anura), salamanders (Caudata), and some crustaceans will aestivate (also spelled estivate)—a drought-driven form of hibernation. They sink down into the mud before it dries completely, sealing themselves in a mucous capsule until the rains come again. If ever there was a time to be glad you can absorb oxygen in the soil through your skin, this is it, because the air in your boggy bubble won’t last very long.

yawning snowy owl by Pat Gaines ccResearchers are intrigued by these alternate forms of sleep and how they might offer clues for solving a variety of human health concerns. Honestly, I understand their fascination but I don’t know how they stay awake long enough to collect any data. Just writing about dormancy has my eyelid feeling so… heavy. I guess it’s… time for…. me to turn… in.

…..Hit the  [YAWN!]  hay.

……….Catch some…..zzzzzzzzz

.

*Pop Quiz:  How many times did you yawn while reading this? 😉

.

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. Thanks to these photographers for making their work available through a Creative Commons license: SearchNetMedia (prairie dog); Pau Davidy (polar bear); Tatiana Bulyonkova (rock dove); Michael Ransburg (turtle); and Pat Gaines (snowy owl).

Read Full Post »

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).

.

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.

.

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!

.

© 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).

Read Full Post »

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)

.

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).

.

Start your day with a little Next-Door Nature—click the “subscribe”  link 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: 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).

Read Full Post »

next-door nature, urban wildlife, wasps, yellowjackets

Love Facebook? You might want to thank a paper wasp (Photo: roadsidepictures, Creative Commons license)

.

Mark Zuckerberg would not be one of 100 wealthiest and most influential people in the world without the help of wasps. I mean the six-legged kind (whether or not two-legged WASPs should get any of the credit is something for attorneys to discuss and will not be addressed here).

It’s a lengthy timeline but easy enough to follow*:

wasps to Facebook timeline

There you have it—no social insects, no social primates and, therefore, no need for a social network. When you think about it, Facebook isn’t just an online community. It’s a kind of virtual hive. You and Mark owe more to wasps that you may have ever realized.

next-door nature, wasps, mud dauberNot all wasps are gregarious, mind you. The majority of species, including mud daubers (Sphecidae), pollen wasps (Masarinae) and potter wasps (Eumeninae) are solitary. You know the type… quiet, poorly developed interpersonal skills, keep to themselves, rarely cause much trouble. A lot of them don’t even have stingers and they take the term “wasp-waisted” to extremes. We’ll respect their privacy, at least for now, and come back for a visit some other day.

Meanwhile, here in the U.S. we have two basic types of social wasps: paper wasps (Polistes spp.) and yellowjackets (Vespula spp. and Dolichovespula spp.). The two groups are often lumped together under the “hornet” tag, but the introduced European hornet (Vespa crabro) is the only true member of that Family found in North America.

With a few exceptions, wasps have two pairs of wings and can be distinguished from bees by that narrow waist (aka petiole) between the thorax and abdomen. The ovipositor (an organ used to prepare and position eggs) of a fertile queen becomes the stinger of an infertile worker females; males are not capable of stinging. Unlike honey bees (Apis spp.), wasps do not leave their stinger behind and are able to deliver multiple injections of venom.

Adult wasps feed on nectar and, as a result, can be classified as pollinators. Some social wasps are omnivorous, feeding on fallen fruit as well as carrion; yellowjackets are especially attracted to open garbage cans and dumpsters, drawn perhaps to the sweet, sticky spillage from nearly empty soda cans and bottles as well as other types of decaying leftovers.

next-door nature, wasp, yellowjacket

yellowjacket (Vespula germanica)

Wasps come in a rainbow of colors, including vivid yellows, metallic blues, and bright reds (keep this helpful rule of thumb in mind when interacting with insects—flamboyant wardrobes usually serve as a “don’t touch!” warning, backed up with some kind of poison or venom). Because they often share a brown or black and yellow color scheme, paper wasps are often misidentified as yellowjackets. I don’t want to encourage you to get up close and personal to make the identification and, luckily, there’s no need. The easiest way to tell them apart is by their nests.

Paper wasps and yellowjackets will nest in trees, under building eaves, in walls, and just about any other place that offers some protection from the elements. Both types of wasp use chewed wood fibers as the main construction material, even when building underground, as yellowjackets often do.

next-door nature, wasp, paper wasp, wasp nestPaper wasp combs attach with a single filament and consist of one tier of adjacent papery hexagonal brood cells for developing larvae. Each cell is open on one end  so you can actually see the contents, if you choose (but please keep a safe distance. Better yet, just look closely at the opening photo above). Typically, a mature nest contains 20-30 adults and rarely grows to more than 200 cells. Paper wasps usually attack only when they or the nest is threatened, but they are territorial. As an interesting aside, the northern paper wasp (Polistes fuscatus) has extremely variable facial patterns and recent research suggests their facial recognition abilities are similar to those of humans and chimpanzees (Pan spp.). Obviously, individuality affords some benefit, even among drones—so much for faceless anonymity.

Yellowjackets prefer to raise their young in a kind of fortress that looks more like what we would think of as a hive, with layers and layers of brood cell combs. The whole structure is completely enclosed with the exception of a single entrance hole. Queens establish new colonies each spring, often returning to the site of a previous nest (the location is identified by a chemical scent marker recognizable even to a first-year queen). However, if the structure is particularly well-protected from the weather—in the wall of a house, say—it may become a perennial nest, populated year-round. Yellowjacket hives may range in size from several inches (at the beginning of the colony’s history) to enormous structures measuring six feet or more and housing as many as 20,000 adult workers.

Wasp control is dangerous, especially for people who have heart conditions or known allergies to the venom, so it’s important to know what you’re dealing with before you take action. There’s a huge difference between avoiding 20 winged assailants and outrunning 20,000.  Moreover, yellowjackets tend to be more aggressive—they don’t give up the pursuit as quickly. [For more information on how to safely manage wasps, download a fact sheet courtesy Drs. Mike Merchant and Glen Moore of my alma mater, Texas A&M. Whoop!]

Don’t be too quick to declare war on wasps, though. In addition to their important role in plant pollination, nearly every pest insect species has at least one wasp species that preys or parasitizes it, making wasps a critically important natural biocontrol that benefit agricultural and even home gardeners. If that’s not enough to convince you to live and let live with wasps, when possible, image your life without social media!

I’m serious—next time you see some wasps congregating around your front porch, take a moment to say thanks… just before you blast the nest with with the hose, knock it down with a broom handle, and then grind it into the sidewalk with your shoe to be sure there are no survivors (don’t act all innocent with me—I can see that can of Hot Shot® behind your back).

When you’re finished, don’t forget to post about it on Facebook!

 

*NOTE:  As new discoveries are made, scientists continually discuss, argue, and refine our understanding of the evolutionary history of life on Earth.  I realize this timeline is simplistic but it is based on currently available research. My intention was to create a captivating introduction to a post on wasps by illustrating a connection between Zuckerberg, social networks, and the Vespidae Family. If you have a nit to pick about my portrayal of the fossil record and its accuracy—cut me a little slack, okay? I’m a writer and an urban wildlife biologist, not a taxonomist. Plus my beloved MacBook Pro died last week so I’m way behind schedule, stressed out, and in mourning (I did pull myself together long enough to purchased a new MacBook Pro and, I must say, it has been incredibly supportive as I struggle overcome my grief.)

.

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!
© 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] roadsidepictures (paper wasp on nest); Malcolm Tattersall (mud dauber); Richard Bartz (yellowjacket on leaf); Bob Peterson (paper wasp nest in situ); and Jason Hollinger (yellowjacket nest).

Read Full Post »

Older Posts »

%d bloggers like this: