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Posts Tagged ‘animal behavior’

The Nissan Watering Hole (Photo: Ingrid Taylar, used with permission)

American robins and other wild creatures have to get creative if they want to quench a winter thirst (Photo: Ingrid Taylar, Creative Commons license)

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Which season comes to mind when you read these words?

parched

desiccated

shriveled

arid

sere

If you’re a wild thing, the answer may well be winter.

Sure, the heat of summer can make any body feel dry as dust. But wild animals, especially species that can tolerate living near people, usually have an easier time finding some moisture when the mercury rises than when it falls.

In cities and suburbs, April brings more than just spring showers. The return engagement of automatic lawn sprinklers turns every pampered landscaping leaf and each blade of carefully tended turf-grass into a diminutive drink dispenser. Fountains splash and spritz and spray. Swimming pools drop all pretense of modesty and shrug off their winter coats. Hoses report for car-washing and child-cooling duty, turning streets and sidewalks into ephemeral streams. Birdbaths and pet bowls brim with cool, clear water.

Squirrel lapping water from window (Photo: David Grant, CC license)Come January, February, and March, creatures have to get creative and a bit brave to quench their thirst, at least in northern climes. Those of us with easy access to indoor plumbing may not realize it, but for wild animals, dehydration is a bigger threat to winter survival than starvation. Even when the clouds are feeling generous, the precipitation they deliver is often in a more or less rigid—and much less quaffable—form. Personally, I like to think of sleet, snow, and ice as the H2O equivalent of hibernation. Unfortunately, water’s winter vacation means more work for those who depend on it.

And that’s everyone. No exception. Animal, vegetable (no, not mineral)… if you’re alive, you not only need to consume water, you are water—60 to 80% water. Even critters who sleep away the short photo-period months depend on water to stay alive, same as the rest of us. They simply tank up pre-torpor and then use the water tucked away in their extra reserves of body fat.

American goldfinch drinking from an icicle (Photo: JDB Photos, CC license)Active animals need water for basic metabolic functions, including proper digestion. This is especially true for seed-eating birds (a group that tends to hang around all year rather than migrate to places where insects and fruit are still on the menu) because there isn’t much moisture in their meals. In fact, it takes extra water to digest high fiber foods.

What happens to birds and mammals who can’t find a source of unfrozen surface water when they need it? The problem is far greater than simply putting up with a dry mouth until you can stop at a convenience store for a bottle of Aquafina. How long an animal can go without water depends on many factors, including their species, weight, physical condition, and parasite load, as well as the weather. Generally speaking, though, it doesn’t take long for life without liquid to get unpleasant. Lose one or two percent of total body water (TBW) and your dehydration is classified as “mild”; however, anyone who’s experienced it (that would be me) is sure to argue that the resulting headache is anything but. The definition of “moderate” dehydration is five to ten percent of TBW… the situation is getting serious now, as your skin dries out and loses turgor (the ability to snap back into place when pinched) and your eyes begin to sink back into their sockets. Over ten percent TBW loss is “severe” enough that you’re unlikely to recover without medical intervention.

The scenario I’ve just described may sound like an environmental disaster waiting to happen… and in cases of actual drought, such as what’s been going on in much of the U.S. the past several years, the impact is rather grim. Under more normal circumstances, winter water is difficult but not impossible to find, and this scarcity offers an opportunity for nature lovers. Want to make wild lives—and wildlife watching—a little easier? Turn on the spigot.

I mean that literally. Providing water can be as simple as letting your outside faucets drip. You probably already do this to protect your pipes from bursting when The Weather Channel warns of freezing temperatures. Perhaps you can afford to do it once a week, or every other day, regardless of the forecast.

BluebirdBath (Photo: Rob and Jane Kirkland, CC license)

If you’d rather keep the water bill low, and the wild ones a little further from the house, birdbaths are a simple way to offer refreshment. They’re easy to maintain, plus you can add an electric, battery-, or solar-powered heater/de-icer to insure that everyone can wet their whistle on even the coldest days. Hard-core backyard habitat aficionados will drool over the possibility of installing a pond or artificial stream. Whatever floats your boat—you’ll find both ends of the water-feature spectrum, and everything in between, at your local watchable wildlife retailer or gardening center.  I promise you, the sound of water is irresistible music to human and non-human ears alike. New resources will be found and greatly appreciated.

What’s more, water is an effective wildlife attractor all year long. When you offer seed, you get seed-eaters (e.g., cardinals, blue jays, house sparrows, and squirrels), some omnivores (e.g., opossums, raccoons, the occasional deer or black bear)—and probably a lot of hulls and other waste that needs to be raked up and thrown away. Feeder maintenance can be an expensive and time-consuming habit. [Be warned, you may also inadvertently lure in some species who like to feast on the feeder regulars. If you find it disturbing to look up from your morning coffee to see a sharp-shinned hawk scattering goldfinch feathers hither and yon, you may find it helps to think of this as progressing from “having a feeder” to “having a food-web.”] Landscape with native plants and you should be able to coax some fruit and nectar fans to visit as well. Few homeowners are willing to do what’s necessary to invite insectivores to dinner, at least intentionally.

But offer everyone something to drink and suddenly your crib is a coffee house, local pub, and hot new club, all rolled into one. Just add water!

[I'm taking a break from writing new posts as I prepare for yet another migration so I'm recycling a few relevant posts to fill in the gap. This one was originally published last year but the message bears repeating. I expect to have a new NDN installment ready for viewing by mid-February.]

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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). Thanks to these photographers for making their work available through a Creative Commons license: Ingrid Taylar (thirsty robins); David Grant (thirsty squirrel); JDB Photos (thirsty goldfinch); and Rob & Jane Kirkland (thirsty bluebirds)..

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arctic fox by emma j bishop cc

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

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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

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

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[FYI: Upcoming changes in employment and residency have caused Next-Door Nature to go into hibernation for a little while. I'll re-publish some past posts while the critters are snoozing to help readers ward off cabin fever, and re-emerge sometime in February (when I hope to get back to a regular posting schedule again). Thanks for your patience!]

There’s nothing quite as invigorating as 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!
© 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).

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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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