It's common around here for us to hear several birds singing at once—especially in spring and summer, when they are declaring their territories, attracting mates, and just feeling good enough to croon and warble. Do birds sing for joy? Do they become energized by beautiful weather and unable to stop themselves from belting out a ballad or two? I don't think anyone knows if birds get excited about a pretty day and if it moves them to song. Regardless, I have decided that they are exhibiting some delight at just being alive. So I say they are singing out of genuine pleasure.
It's a delight to hear all the various bird ballads overlapping each other, as if they are in competition to see who can win the Avian Opus Award. It's an added bonus when I am able to watch a bird sing, while it is nearby. It's an uncommon experience, since most birds keep pretty quiet when a human is around. On those rare occasions when I'm close enough I can see its body swell up or its bill point to the sky, as it quivers during its burst of song.
Birds are literally built to sing. When we humans talk or sing, we use only about 2% of our exhaled air. Birds are far more efficient—they use virtually all of their out-breath. Our larynx is our voice box, which contains our vocal cords, the source of sound. Birds have a much more complex sound mechanism, that begins in what's called their syrinx. Just at the juncture of their bronchi (the two windpipes from their lungs) with the trachea, the walls of the syrinx have many tiny muscles that change its shape and generate their complex songs.
These muscles are so intricate that a bird can sing anywhere from a single note to a complex blend of harmonic multiple tones. In fact, some birds—the operatic thrushes, for example—can sing two songs simultaneously; sort of like a two-handed piano player, but with one throat! Try that sometime! The sounds that emanate from the syrinx muscles get further changed when a bird pulsates its throat or wiggles its head or bill. The result is an artistic concert that can't be beat.
Some 60% of all birds are true songbirds—the real melodic singers of the avian family. The remainder of birds don't really sing; they're quackers, screamers, croakers, cooers, squawkers, clatterers, and (bill) snappers.
Not only do we not know if birds sing from enjoyment, we are quite ignorant of how much information they communicate to each other when they make sounds. Sure, they may be declaring territory or wooing a mate, but they obviously send other kinds of messages that we can only guess at. There are subtleties to their language that we have yet to learn.
We humans tend not to give birds (or most any other animal) much credit for intelligence, because their simple vocalizations do not seem to have the range of meanings that our words do. But when birds who are able to imitate our words—such as parrots—learn a good number of words, we find them going on to construct simple sentences in creative ways. We tend to look upon this as a lower form of intelligence, when it's really not fair to judge their cognitive abilities on the basis of well they manipulate our language—something quite alien to them. How would space traveling beings from elsewhere look upon our mental capabilities, after we learn a handful of their “words” and then tried to use them to construct simple phrases?
Turn it around, and humans do a pretty poor job of making sense of animal language and forms of communications. It's pretty obvious from those who closely observe animals that their ability to communicate is very sophisticated, when we see how intelligently they respond to their environment. In fact, most of us can't even whistle the simplest of bird songs! And if we develop a rudimentary skill at it, we completely miss the nuances that birds easily pick up, such as regional accents, the age of the singer, the distance between them, how serious the caller is, etc. Birds not only can understand these details, but can discern the call of a close relative from among the simultaneous sounds of many birds of the same species—such as penguin parents locating their chick from among a crowd of hundreds. Is that not an exceptional skill?
While I recognize my ignorance of most of the meaning and message of birdsong, I still can thrill to their concerts and even imagine what they're saying. Although it may add to my deeper understanding if I were able to know who is the composer of particular strain of orchestral music I hear, I can still thrill to the sensation it brings to the back of my neck. A bird's artistry makes me pause in my work and become absorbed by the beauty of his song. And the more I listen, the more I hear and appreciate. I've got lots of listening to do!
[Some of the specifics of how birds make their songs I got from a neat little book by Barry Kent MacKay: Bird Sounds, 2001.]
Friday, June 24, 2011
Monday, June 20, 2011
Tuesday, June 14, 2011
Vanishing Vultures
Few birds elicit more contradictory responses than the turkey vulture. Spot one soaring gracefully overhead and you'll likely respond with, “Ooh, look at that! Isn't it stunning?” Spot one alongside the road, feasting an a dead carcass and you're more likely to respond with, “Yuck! What a revolting sight.”
The turkey vulture is widespread across the US, and is an important bird. Like the dung beetle and the maggot, the vulture plays a major role in nature's recycling system. Still, we'd much rather watch a songbird daintily peck at seeds than see a vulture picking over the decaying carcass of roadkill.
They have eyesight nearly as acute as eagles and can spot carrion from high in the air—although they are also one of the few birds who have a keen sense of smell. Their version of an enticing fragrance, however, does not emanate from flowers. And vulture babies are even more revolting—they eat their parent's regurgitated spoiled food: tainted vulture vomit!
Vultures are big birds... well, really quite smaller than the resident feathered friend on Sesame Street. They are nearly the size of an eagle, with a wingspan of almost six feet. When gliding overhead they can be mistaken for a hawk. Years ago I was easily confused, but slowly learned to readily distinguish between them. The underside of a vulture's wings is dark, while a hawk's is nearly white. While the hawk's head is large and fierce looking, a vulture's head is tiny and naked, and almost appears headless at a distance. And if the glider emits any kind of shrill call, it's a hawk. Vultures are very quiet birds—as if not wanting to attract attention to their repellent sight.
On the ground the turkey vulture—as its name suggests—resembles a wild turkey, with both of them sporting a bare pate. The turkey's baldness helps it to cool down, while the vulture's naked noggin allows him to dive deeply into the innards of his meal and not have to clean feathers later (or, heaven forbid, have to endure the bad smell and unsightly appearance of crusted feathers).
The resemblance between them, however, stops with the bald head. If the bird has a neck, it's a turkey. The vulture's tiny bean needs little neck to support it. If it walks pertly along, it's a turkey. Vultures hop and waddle like a drunkard. But if you see the bird has whitish legs, you know it's a vulture—they have the revolting habit of squirting their liquid feces on their legs, because the evaporating liquid cools them. But then again, maybe they prefer the aroma.
I don't think many people would want a vulture for a pet. It makes me wonder, given that they are are an exception in birddom with their sense of smell, how they can stand their own stink. But I guess that's true of all of us. The other guy's farts always smell worse than ours.
Another interesting fact about the turkey vulture is that it has been slowly migrating northward in the US. A recent article in Living Bird magazine from Cornell University's Lab of Ornithology describes this phenomenon. A century ago Virginia was the northern extent of their territory. Now they can be seen well up into Canada. Why the movement north? Researchers are not certain. There could be several possibilities. First, climate change is forcing many species to head towards cooler territory. Second, some birders think the overpopulation of deer in the Middle Atlantic states and New England might be drawing the vulture in, as cars create an increasing number of deer carcasses roadside. Third, half a century ago DDT was widely used in the South, causing many birds to weaken. Now that southern vultures are more healthy and more populous, some might be foraging farther north for carrion.
Fourth, southern farms have slowly transformed from small livestock homesteads—where dead cattle were left in the field to the vultures and other scavengers—to today's large vegetable enterprises, with few cattle. Additionally, contemporary farmers can use their tractor to rapidly bury an expired cow or call the local rendering plant, rather than labor for a couple of days digging by hand, as the old timers had to do. And what busy farmer was going to be able to afford that much time, just to bury a useless cow?
Several years ago I had a neighbor tell me that he feared for the survival of the turkey vulture—although he called them buzzards. Now that farmers were no longer leaving dead livestock in the fields, he worried that vultures would become extinct. I was rather skeptical of his concern—partly due to my ignorance of the fact that farmers were now properly disposing of dead animals, but also because scavengers (think coyotes and crows, as well as vultures) are very resourceful creatures. Now that I know better, thanks to Cornell, I could console my neighbor by telling him, “It's OK, George, they're doing fine, they're just headed north.” In fact, the turkey vulture opportunistically dines on many other dead critters than cows and deer. I think there will be plentiful roadkill around here to keep the vulture soaring overhead (“Ooh! Isn't that stunning?”) for some time yet.
The turkey vulture is widespread across the US, and is an important bird. Like the dung beetle and the maggot, the vulture plays a major role in nature's recycling system. Still, we'd much rather watch a songbird daintily peck at seeds than see a vulture picking over the decaying carcass of roadkill.
They have eyesight nearly as acute as eagles and can spot carrion from high in the air—although they are also one of the few birds who have a keen sense of smell. Their version of an enticing fragrance, however, does not emanate from flowers. And vulture babies are even more revolting—they eat their parent's regurgitated spoiled food: tainted vulture vomit!
Vultures are big birds... well, really quite smaller than the resident feathered friend on Sesame Street. They are nearly the size of an eagle, with a wingspan of almost six feet. When gliding overhead they can be mistaken for a hawk. Years ago I was easily confused, but slowly learned to readily distinguish between them. The underside of a vulture's wings is dark, while a hawk's is nearly white. While the hawk's head is large and fierce looking, a vulture's head is tiny and naked, and almost appears headless at a distance. And if the glider emits any kind of shrill call, it's a hawk. Vultures are very quiet birds—as if not wanting to attract attention to their repellent sight.
On the ground the turkey vulture—as its name suggests—resembles a wild turkey, with both of them sporting a bare pate. The turkey's baldness helps it to cool down, while the vulture's naked noggin allows him to dive deeply into the innards of his meal and not have to clean feathers later (or, heaven forbid, have to endure the bad smell and unsightly appearance of crusted feathers).
The resemblance between them, however, stops with the bald head. If the bird has a neck, it's a turkey. The vulture's tiny bean needs little neck to support it. If it walks pertly along, it's a turkey. Vultures hop and waddle like a drunkard. But if you see the bird has whitish legs, you know it's a vulture—they have the revolting habit of squirting their liquid feces on their legs, because the evaporating liquid cools them. But then again, maybe they prefer the aroma.
I don't think many people would want a vulture for a pet. It makes me wonder, given that they are are an exception in birddom with their sense of smell, how they can stand their own stink. But I guess that's true of all of us. The other guy's farts always smell worse than ours.
Another interesting fact about the turkey vulture is that it has been slowly migrating northward in the US. A recent article in Living Bird magazine from Cornell University's Lab of Ornithology describes this phenomenon. A century ago Virginia was the northern extent of their territory. Now they can be seen well up into Canada. Why the movement north? Researchers are not certain. There could be several possibilities. First, climate change is forcing many species to head towards cooler territory. Second, some birders think the overpopulation of deer in the Middle Atlantic states and New England might be drawing the vulture in, as cars create an increasing number of deer carcasses roadside. Third, half a century ago DDT was widely used in the South, causing many birds to weaken. Now that southern vultures are more healthy and more populous, some might be foraging farther north for carrion.
Fourth, southern farms have slowly transformed from small livestock homesteads—where dead cattle were left in the field to the vultures and other scavengers—to today's large vegetable enterprises, with few cattle. Additionally, contemporary farmers can use their tractor to rapidly bury an expired cow or call the local rendering plant, rather than labor for a couple of days digging by hand, as the old timers had to do. And what busy farmer was going to be able to afford that much time, just to bury a useless cow?
Several years ago I had a neighbor tell me that he feared for the survival of the turkey vulture—although he called them buzzards. Now that farmers were no longer leaving dead livestock in the fields, he worried that vultures would become extinct. I was rather skeptical of his concern—partly due to my ignorance of the fact that farmers were now properly disposing of dead animals, but also because scavengers (think coyotes and crows, as well as vultures) are very resourceful creatures. Now that I know better, thanks to Cornell, I could console my neighbor by telling him, “It's OK, George, they're doing fine, they're just headed north.” In fact, the turkey vulture opportunistically dines on many other dead critters than cows and deer. I think there will be plentiful roadkill around here to keep the vulture soaring overhead (“Ooh! Isn't that stunning?”) for some time yet.
Sunday, June 12, 2011
Thursday, June 9, 2011
Betty Lou The First Berry Cultivator—Part 2
Life was comfortable, simple, and safe for Betty Lou's People. They had a rich social life—spending their days in close contact and working cooperatively together. No one was considered the leader. It was a very democratic group. They fairly shared food and other resources. Everyone had a role to play, and the life of the small band flowed quite peacefully from day to day.
The People's hunters were all men—the younger, stronger, and faster males. A party of three to five of them would embark on a hunt that could last for several days and cover a lot of territory. They would injure an animal (their weapons were not at all powerful) and then have to track it for days, until it finally fell and died. If they were successful, they'd return to camp with a bunch of meat which got equally divided among members of the clan.
The band's gatherers were mostly women, accompanied and assisted by a few older children. Betty Lou was a key member of the gathering group. She was a little healthier, stronger, and more curious than most of her cohorts. She and her team might be gone a couple days, seeking high calorie foods such as roots, nuts, tubers, and berries. Their contribution to the clan's diet was in some ways more crucial than the men's—who sometimes returned home empty handed. Betty Lou and her teammates often carried heavy loads on their return—as much as 70 pounds or more.
On their way out and upon returning from their foraging activities, the women would carry food that could be stored (such as roots and nuts) but eat nutritious food along the way that would otherwise quickly spoil. One day, on the way back to camp, Betty Lou spotted some juicy berries behind a little hillock. Knowing that they'd not keep, she quickly ate them for a boost of energy and continued on home. Upon arriving she relieved herself behind some bushes and then joined in the sharing process.
A couple of months later Betty Lou was headed for her favorite spot to defecate, when she spotted some new shoots growing from her previous deposits. Little did she know at the time that, after returning from her last foraging trip and eating berries along the way, she had pooped out the seeds which had now sprouted.
Being an inquisitive and observant type, Betty Lou looked more closely at the tender leaves and noted that they looked very similar to those of the berry bush from which she'd enjoyed a tasty snack. “Hmmm,” she thought, “I wonder what's happening here. Seems to be something important.” Being also a patient Person, she decided to keep a close eye on this little plant. Sure enough, in another few weeks berries began to form.
Betty Lou wasn't at all sure how this happened, but her curiosity was definitely piqued. She ran a few more simple “crappy” experiments over the next several months and began to realize she was onto something. Slowly she developed the understanding that berries could be cultivated and even came to understand that it was the hard little indigestible pits that caused the berries to grow.
As she grew older—she reached the ripe old age of 53—Betty Lou honed her skills at cultivating berries and a few other plants that the clan ate. She passed her knowledge on to other women and her clan prospered. Eventually the news spread to other clans: all their food did not have to be gathered from the wild and they did not have to rely on the fickle fortunes of nature to provide them food. Some of it could be grown by poking a hole in the ground and dropping in a seed. Human beings were on their way to an agricultural society. And the Africans and early Sumerians were grateful enough that they faithfully kept Betty Lou's story alive for a few millennia, until it could be written down.
[Note: Although I took some liberties with the “facts” on the Sumerian archeological finding, the account of how our hunter-gatherer forebears transitioned to cultivators is probably pretty accurate.]
The People's hunters were all men—the younger, stronger, and faster males. A party of three to five of them would embark on a hunt that could last for several days and cover a lot of territory. They would injure an animal (their weapons were not at all powerful) and then have to track it for days, until it finally fell and died. If they were successful, they'd return to camp with a bunch of meat which got equally divided among members of the clan.
The band's gatherers were mostly women, accompanied and assisted by a few older children. Betty Lou was a key member of the gathering group. She was a little healthier, stronger, and more curious than most of her cohorts. She and her team might be gone a couple days, seeking high calorie foods such as roots, nuts, tubers, and berries. Their contribution to the clan's diet was in some ways more crucial than the men's—who sometimes returned home empty handed. Betty Lou and her teammates often carried heavy loads on their return—as much as 70 pounds or more.
On their way out and upon returning from their foraging activities, the women would carry food that could be stored (such as roots and nuts) but eat nutritious food along the way that would otherwise quickly spoil. One day, on the way back to camp, Betty Lou spotted some juicy berries behind a little hillock. Knowing that they'd not keep, she quickly ate them for a boost of energy and continued on home. Upon arriving she relieved herself behind some bushes and then joined in the sharing process.
A couple of months later Betty Lou was headed for her favorite spot to defecate, when she spotted some new shoots growing from her previous deposits. Little did she know at the time that, after returning from her last foraging trip and eating berries along the way, she had pooped out the seeds which had now sprouted.
Being an inquisitive and observant type, Betty Lou looked more closely at the tender leaves and noted that they looked very similar to those of the berry bush from which she'd enjoyed a tasty snack. “Hmmm,” she thought, “I wonder what's happening here. Seems to be something important.” Being also a patient Person, she decided to keep a close eye on this little plant. Sure enough, in another few weeks berries began to form.
Betty Lou wasn't at all sure how this happened, but her curiosity was definitely piqued. She ran a few more simple “crappy” experiments over the next several months and began to realize she was onto something. Slowly she developed the understanding that berries could be cultivated and even came to understand that it was the hard little indigestible pits that caused the berries to grow.
As she grew older—she reached the ripe old age of 53—Betty Lou honed her skills at cultivating berries and a few other plants that the clan ate. She passed her knowledge on to other women and her clan prospered. Eventually the news spread to other clans: all their food did not have to be gathered from the wild and they did not have to rely on the fickle fortunes of nature to provide them food. Some of it could be grown by poking a hole in the ground and dropping in a seed. Human beings were on their way to an agricultural society. And the Africans and early Sumerians were grateful enough that they faithfully kept Betty Lou's story alive for a few millennia, until it could be written down.
[Note: Although I took some liberties with the “facts” on the Sumerian archeological finding, the account of how our hunter-gatherer forebears transitioned to cultivators is probably pretty accurate.]
Monday, June 6, 2011
Saturday, June 4, 2011
Betty Lou The First Berry Cultivator—Part 1
For several hundred thousands of years before Homo sapiens became farmers—in the form of the first Sumerian agriculturalists—our deep ancestors lived as hunter-gatherers. They lived in balance with their world. Like animals, they trod lightly on their Earth. They were few in number, took only what they needed, and left little or no trace of their presence.
When their ancestors—apelike hominids—came down out of the trees and began to live on the savannah, they had to learn to exist in the open, finding sustenance while avoiding the numerous predators that would stalk them. They succeeded in thriving in this risky environment, and found ways to cohabit with lions and leopards, as bipeds and quadrupeds learned how to grant the other necessary space to live, without major threat to either.
Our ancestors most likely began their carnivorous diet by finishing off kills left by the big cats or hyenas. Over time their hunting skills improved, as they began chasing down and killing the slower moving, large herbivores, as well as learning how to snatch small game. They supplemented this meat diet with a wide variety of plants—tubers, nuts, fruits, and other vegetables. In fact, vegetation was the major part of their diet.
Archeologists recently made an amazing discovery in a far-flung province of Turkey, at the site of an eight thousand year-old Sumerian settlement. They found primitive clay tablets that were inscribed with very ancient characters that predate a type of script used on later Sumerian tablets. It appears that the story told by the tablets is about how the Sumerians learned to develop agriculture—describing the pioneering work of a much earlier ancestor in Africa. It seems that earlier cultures, dating back as far as 12 millennia ago, had told and retold the story of how this horticultural trailblazer had come upon the method of planting seeds to grow edible vegetables. The actual identity of the first cultivator had been lost in the repeated telling of her story, so the archeologists named her Betty Lou. This is her story.
She lived something on the order of 15,000 years ago (as best could be determined from the tablet cuneiform inscriptions) on the African savannah. Betty Lou was a member of a band of hunter-gatherers, composed of an extended family of about 20 People. And “People” was what they called themselves. As far as they knew, they were pretty much the only living beings like them in the world, for their world was very small. They lived a semi-nomadic existence—settling for a few months around a water hole and then moving on when the water dried up or the local plants and game were no longer easily available.
Betty Lou's band might move four or five times a year—rotating around the region. On extremely rare occasions they would encounter a similar group of humans. They might exchange food or other items, or on even more rare occasions take mates, but those neighboring bands were so infrequently encountered that they did not even consider them to be People. As often as not, they'd fight them.
More on Betty Lou's discovery next time...
When their ancestors—apelike hominids—came down out of the trees and began to live on the savannah, they had to learn to exist in the open, finding sustenance while avoiding the numerous predators that would stalk them. They succeeded in thriving in this risky environment, and found ways to cohabit with lions and leopards, as bipeds and quadrupeds learned how to grant the other necessary space to live, without major threat to either.
Our ancestors most likely began their carnivorous diet by finishing off kills left by the big cats or hyenas. Over time their hunting skills improved, as they began chasing down and killing the slower moving, large herbivores, as well as learning how to snatch small game. They supplemented this meat diet with a wide variety of plants—tubers, nuts, fruits, and other vegetables. In fact, vegetation was the major part of their diet.
Archeologists recently made an amazing discovery in a far-flung province of Turkey, at the site of an eight thousand year-old Sumerian settlement. They found primitive clay tablets that were inscribed with very ancient characters that predate a type of script used on later Sumerian tablets. It appears that the story told by the tablets is about how the Sumerians learned to develop agriculture—describing the pioneering work of a much earlier ancestor in Africa. It seems that earlier cultures, dating back as far as 12 millennia ago, had told and retold the story of how this horticultural trailblazer had come upon the method of planting seeds to grow edible vegetables. The actual identity of the first cultivator had been lost in the repeated telling of her story, so the archeologists named her Betty Lou. This is her story.
She lived something on the order of 15,000 years ago (as best could be determined from the tablet cuneiform inscriptions) on the African savannah. Betty Lou was a member of a band of hunter-gatherers, composed of an extended family of about 20 People. And “People” was what they called themselves. As far as they knew, they were pretty much the only living beings like them in the world, for their world was very small. They lived a semi-nomadic existence—settling for a few months around a water hole and then moving on when the water dried up or the local plants and game were no longer easily available.
Betty Lou's band might move four or five times a year—rotating around the region. On extremely rare occasions they would encounter a similar group of humans. They might exchange food or other items, or on even more rare occasions take mates, but those neighboring bands were so infrequently encountered that they did not even consider them to be People. As often as not, they'd fight them.
More on Betty Lou's discovery next time...
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