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Monday, April 18, 2011

One Becomes Three

Our old ewe decided to do us a favor and drop her lambs in the middle of a relatively pleasant Sunday afternoon, when we would be easily available to help her out.  She's taken advantage of our assistance during the two previous lambings, even when the lambs are lined up nicely without tangled legs or twisted heads, and ready to go with a good push.  Buttercup doesn't seem to want to push anymore.  Maybe she's decided she's too old for heroics when there is help available.  She's a wise old sheep.

Dan begins the assist, drawing on the front legs of the lamb.

The lamb is almost out.  They are incredibly slippery.

Touchdown!

First wide-eyed look at a new world.

Buttercup does her stuff.

With an assist, the new lamb is soon delivered onto the straw, and the old ewe immediately begins cleaning off the membranes and fluid, rasping steadily with her rough tongue and chuckling away.  Sheep have a special gutteral bleat they use just for their newborn babies.  The lamb soon answers, a high-pitched protest.  What must it be like, to go from tight hot darkess, into cold bright light and too much space in a matter of seconds?  The lamb works to rise, stumbling and flopping forward and sideways.  She soon has mastered tucking her shockingly long legs tight under her body, and within a few minutes of that, she can rise and stand.  At this point, we deliver the second lamb, and while Buttercup begins another round of cleaning and chuckling, the first lamb finds her udder, and after several long minutes of apparent confusion, she takes her first meal of rich milk.  The second lamb soon follows.

Despite thousands of years of domestication and intense selective breeding, they all know what to do.  It is easy to understand the need for a wild lamb to quickly climb to its feet and feed, and be ready to either run or hide within minutes of its birth.  It is harder to imagine the slow steps along that evolutionary journey, the process of encoding these complex behaviors into genes piece by piece.

This morning we only had one sheep, our old ewe with her low-hanging udder and enormous swollen body, standing a bit dejectedly by the fence.  The ewe is now fired up with a new purpose, both protective and nuturing, carrying on the instructions that have carried life through the ages.

So one became three.

Postscript. This morning I rode my bicycle by the pasture at dawn, and saw Buttercup resting in the shed with her two lambs curled up in tight black commas beside her.  It was cold last night, with a light frost.  Imagine your first day, watching an overcast afternoon fade into nightfall and cold moonlight.  You keep warm by pressing one side of yourself into your dam, while the little meal of milk that is all your stomach can hold has to fire up your body heat, something you've never had to do for yourself before.  What is that like for a lamb, or any other newborn animal that is born aware of its surroundings?  The sun was just edging up over the ridge when I saw them this morning, washing the hilltops with the promise of a day without rain.  The lambs looked out from their shelter at their lives opening out before them.

Sunday, April 10, 2011

Soundscapes

I bought a small tape recorder recently, and decided to record the chorus of Pacific tree frogs in a nearby wetland next to our road.  I chose a nice warm rainy night and the frogs obligingly sang their hearts out, for love, for mates, for genetic fitness, maybe just for the sheer joy of it.  Whatever the reason, they filled the darkness with their urgent sound.

I couldn't record for more than a minute or so before the performance was interrupted by the sounds of tires on wet pavement, leaving a lower-intensity backwash of sound in the vehicle's wake.  The frogs kept singing through most of the interruptions, which was a good thing or they would have lost much of their stage time even on this relatively quiet dead-end road.  It got me thinking of how all the racket we make affects other organisms.

Pacific Tree Frog, Pseudachris regilla.  Photo: thewakingdragon


We are a visual species, despite using sound extensively for intraspecific communication.  If you sat down and described your favorite place, would you include sounds at all?  Even when we talk about concepts, we use visual imagery: as you can see from the big picture, if we took the long view, we could see the problem through to its logical conclusion.  We don't even have the language for a soundscape.  Do we call it the big audio?  The whole noise?

Bryan Pijanowski and four colleagues explore the ecology of soundscapes in a review article recently published in the journal Bioscience. The basic working idea is captured by the Sender-Propagation-Receiver model, where the sender's biophysical characteristics and intent shape the form of the message.  The message may be further modulated by its passage through the physical environment, and its ultimate effect depends on the perception and interpretation of the recipient.  The male frogs' individual success not only depends on the quality of the competition, but also the ability of their calls to carry successfully to the ears of female frogs who will undersand the message- and respond as the males desperately hope they will.

Pacific tree frog, Pseudachris regilla, singing. Photo: GregTheBusker

You can also break sounds down into three general categories.  Geophony describes the sounds of the natural environment that are from physical processes.  Think of the sound of wind hissing across long grass, the sharp pure crack of rockfall, or the extraordinary sound of moving water.  Biophony are noises made by living organisms, although Pijanowski and Company seem to reserve the term for non-human organisms.  Birdsong is obvious; the sounds of a slug munching vegetation, or the whir of a beetle's wings, a little less so.  Finally, the sounds made by Homo sapiens are classed as anthrophony.  It is probably a relevant distinction, because even though we're very much a part of the biological fabric, the vast majority of the noise associated with us is empty of meaning.  Think lawnmower, or air conditioning, or the sounds of vehicles on wet pavement.  That's not to suggest chewing slugs are communicating, but the noise is relevant to slug predators such as ground beetles or garter snakes.

Do we affect the natural world with our racket?  There is a great deal of concern now about ocean noise pollution interfering with the communication and navigation of marine life.  European robins shift the timing of their song in noisy environments.  Song sparrows shifted the lower-frequency notes upwards in their songs, and great tits use higher pitches when confronted with more ambient noise.  In short, the din of civilization has an impact, one we are just starting to recognize and measure.

Song sparrow, Melospiza melodia.  Photo by Alan Vernon


Our cacophony of meaningless noise may have another undesirable effect, this one on us.  We fill our leisure time with the sounds of music or podcasts or television, which have become so portable we can take them right into the very heart of biophonic and geophonic symphonies in progress.  Hearing loss is so obvious and so well publicized it hardly bears mentioning.  But, if we navigate our world by cultivating the skill of blocking out the sounds surrounding us, how well can we listen and actively hear when confronted with an environment that demands it?

Fortunately, very few of us need worry about the signals of natural sound.  We might miss the sudden snap of a branch broken by the deer, the liquid silver of moving water, or the sex calls of frogs, but our lives don't immediately depend on our hearing those signals.  But, by choosing to venture into natural environments without opening ourselves to one of the major dimensions of experience they offer to us, we do perhaphs further alienate ourselves from our biological roots.  Further losing our sense of place on this small planet may not be a matter of just making meaningless noise.