Tuesday, July 29, 2014
Saturday, July 26, 2014
Testy Tim Titmouse
I
sit in my outdoor tub, watching birds come to the feeder. When I'm in
a meditative mood, beholding birds is one of the more absorbing
activities that I enjoy. There is always an interesting example of
bird behavior to observe—and sometimes a taste is offered that
appears to be just enough different from the norm that it captures my
imagination and causes my speculative mental juices to flow.
Tonight
I'm witnessing a group of half a dozen tufted titmice visiting the
feeder—swooping down more or less together, grabbing sunflower
seeds and then flying off more or less together into the evening air.
In a few minutes they return and resume feeding. They pay each other
little attention, except for the fact that they hang with one another
in this loosely-defined flock. It's safer for them, as many eyes do
better at spotting threats than do just two.
Then
there's the oddball in this small flock, whom I will call Testy Tim.
He seems more interested in his fellow group members, than the seeds.
He suddenly attacks another titmouse—excreting a squeaky,
threatening shout that drives the other bird off. At random moments
Tim aggressively charges another compatriot, chasing it away.
What
is going on here? Tim's behavior, it seems to me, is untimely. Such
belligerent conduct in early spring—when territory and breeding
pairs are being established—is normal. But not this time of summer.
Mates have been selected long ago and most offspring bred; now it's
time to mellow out in the summer's heat. But not Testy Tim.
What's
got Tim's goat? Why is he acting so pugnacious? Did he just get
jilted by his lady? Is this a temporary affliction? Did something
just happen that's got his testosterone flowing? Did he just pick a
fight with a bird who was superior to him on the pecking order, and
he won—with his success now surging through his veins like piss and
vinegar? Or might he be a recent fledgling—and like an
overconfident teenager, is engaging in foolish behavior, inviting an
older, more worldly bird to put him in his place?
Tim
is asking for his comeuppance, I'm thinking. He's the single
belligerent bird in this harmonious group; the others may
decide to gang up retaliate at any moment. They seem uninterested in
facing Tim down, however. Maybe it's just too much of an effort in
the hot evening sun, to deal with his attacks? Maybe Tim will soon
get it out of his system and calm down?
The
titmice once again fly off in their group—with Testy Tom trailing
behind. Things quiet down. In a few moments I hear a titmouse
ferociously scolding. Could it be an elder who is chewing out
Tim—advising him to chill out? Has Tim's juvenile behavior earned
him a well-deserved dressing down?
I
don't see any more titmice, as dusk settles in and quiet prevails.
Did Tim finally calm down? Did the others just head for bed, hoping
that tomorrow will be a more agreeable day? I'm left alone with my
musings, to create my stories.
Tuesday, July 22, 2014
Saturday, July 19, 2014
Crustacean Cognition
As
far as mental acuity goes, crustaceans have been considered to be
near the bottom, when evaluating the brains of various families of
animals. Crustaceans are arthropods, which include other simple
critters like insects and spiders. In particular, crustaceans are
hard-shelled animals (the root of the word crustacean is “having a
crust”), such as lobsters, crabs, crayfish, and shrimp. Until a
couple of years ago, many scholars thought that the brains of
crustaceans are so primitive that they can't even feel pain. This
allowed seafood lovers to plunk a live lobster in a pot of boiling
water, conscience free, believing it to be so stupid that it did not
suffer. Now we know better.
A
recent scientific finding coming out of the University of Bordeaux
shows us that crustaceans are not only able to feel pain, but possess
an even greater cognitive ability: they also feel stress. In fact,
the study showed that their tiny brains are influenced by some of the
same chemicals that our massive human brains respond to. Ahh, I love
it... one more belief about the uniqueness of the human species gets
shattered. We keep finding evidence that narrows the gap between us
and all the other animals. And here's yet another one.
The
research conducted by the French scientists conclusively showed that
crayfish can experience rudimentary emotions. How? When they gave
crayfish a mild electric shock, the creatures hid in dark corners of
their aquarium—unlike their unshocked brethren, who did not
hesitate to boldly venture into the light. And the shocked crayfish
behaved as if they were stressed or shy.
Wondering
what might be going on chemically within the tiny crayfish brain, the
researchers guessed that it could be due to elevated levels of
serotonin—which also affects the moods of humans, when a serotonin
imbalance occurs in our brains. When they injected the stressed
crayfish with a drug used to treat anxiety in humans, the critters
calmed down and began venturing into the light. Crayfish on Prozac!
I
don't think that these results imply that we need to begin training
crustacean shrinks to counsel depressed lobsters and crayfish. But
they do tell us that yet one more mental barrier between us and
simple animals has been dismantled. It makes sense that all
animals—including humans—have many mental similarities, given
that we all have evolved from the same primitive ancestor that came
into being some 3.5 billion years ago. We're all together!
Thursday, July 17, 2014
Monday, July 14, 2014
Ain't Like an Ant
The
previous posting described some interesting ways in which our human
behaviors are similar to ants: they “domesticate” other critters
and milk them, they farm, and they “sing” as they work. It's
enlightening to open ourselves to the fact that other forms of life
on Earth bear a greater resemblance to us than we've long thought.
We've historically tended to place our species on a pedestal—greatly
elevated from other critters. We've viewed ourselves as much closer
to the gods. In the modern era, however, we have come to understand
that there is far less of a difference between ourselves and simple
creatures... such as ants.
When
ants form a colony something very sagacious emerges: a level of
intelligence that can rival human capabilities. It is useful to find
ourselves toppled from our self-imagined pedestal, and realize the
similarities and unity of all life on Earth. After all, every one of
us has evolved from the very same primal life form. We're just
different branches and twigs on the same tree of life.
While
describing a few similarities between humans and ants in the previous
post, I think it's also interesting to consider some ways in which we
ain't like ants. They are unique little critters who possess
some remarkable qualities that we can't begin to imagine. If only we
had some of their skills...
We
have language, giving us a sophisticated form of communication. Ants
may not be able to talk as we do (How could a mandible purse its
lips?), but they “speak” to each other in a very sophisticated
language: they use dozens of different types of pheromones to
communicate. They combine various kinds of pheromones to give each
other various kinds of messages. The most common use is to lay down a
pheromone trail that guides sister ants to a stash of food, the
garbage dump, burial grounds, or the way back home.
Ants'
pheromone chemicals are incredibly potent—they need to be, when you
think about one tiny ant laying down a path over several yards long.
In fact, scientists have demonstrated that just a single milligram of
pheromone (less than a thousandth of an ounce!) can lay down an ant
trail that would circle the Earth 60 times!
While
humans tend to come in one size, some ants (even of the same species)
may be 200 times larger than others (depending on the individual
duties of each of them in the colony)! Each size ant has its specific
job within the colony, and they cooperate beautifully, to accomplish
their sophisticated tasks. Think how a human being, 200 times larger
than another human of the same species, would treat its tiny
relative.
When
it comes to the subject of sex, humans and ants could hardly differ
more. The colony is composed entirely of females—all sisters, the
daughters of one queen. When a nascent female ant mates with a male
(who immediately thereafter perishes), she becomes a queen who stores
the sperm in her body for 10 years and more, to fertilize millions of
eggs. Not much of a sex life!
So
the next time you spot an ant trotting across the floor, you might
ponder the various ways it is like us (farming, domesticating other
critters, and singing as they work), as well as the ways we are alien
(pheromone communication, size, and sex). Ain't life's variations
grand?
Saturday, July 12, 2014
Tuesday, July 8, 2014
Am Like an Ant
Ants
are fascinating creatures, which is why one of my mentors, E.O.
Wilson—a distinguished professor and researcher at Harvard—has
devoted many decades to the study of their behavior. Wilson was one
of the first scholars to describe an ant colony as a “superorganism,”
which defines the colony as exhibiting an intelligence and cognitive
ability that is far beyond the capabilities of any one ant.
Scientists refer to this phenomenon as an “emergent” quality. It
is a capability that no human theory or model can predict—it's
almost as if it magically appears when a large number of simple
creatures cooperate.
We
humans tend to look down upon lowly ants as primitive creatures,
because any single ant is rather rudimentary, when compared to
one of us. An ant doesn't have much of a brain and its behaviors are
extremely limited. Yet a colony of ants can perform acts that are
strikingly similar to us. Here are a few examples.
Some
ant species herd and milk bugs, rather like we herd and milk cattle
and sheep. Some ant species are very sophisticated farmers—they
are, in fact, considered to form highly-civilized farming
communities. Millions of years before we humans discovered
agriculture, these ants evolved into accomplished farmers. They are
commonly known as leafcutter ants. They harvest leaves of plants (or
portions of leaves), which they cut and drop to the ground, where
sister transporter ants carry the fragments back to the “farm.”
It's not the leaves they are interested in, but the fungus that they
cultivate on the leaves and then consume. Our human ancestors could
have learned a trick or two about farming from these ants.
Have
you ever hummed a tune, as you engage in some routine task? Well,
ants do it, too. As the leafcutter ants scissor away at a leaf, they
“sing” by rubbing body parts together (sort of like crickets).
But these little singers are smart—their singing helps them in
their surgical efforts, by assisting their mandibles (their chewing
mouth parts) to cut a leaf more efficiently. But they also sing for help. If
one ant gets trapped, it cries (oops, sings) out for its sisters to
come to the rescue.
We
may look at a tiny ant and experience it as an alien critter, but
it's more like us than first meets the eye. If we take a closer
look—as E.O. Wilson has done all his life—we begin to understand
the similarities in our behavior. I may look down upon it, but in
many ways I am like an ant.
Next
time: ways we ain't like an ant.
Sunday, July 6, 2014
Moving Soon
A flock of grackles resting, talking noisily, just before flying off together to feast again. They seem to be auditioning for a part in Alfred Hitchcock's "The Birds".
Thursday, July 3, 2014
Migration Mysteries
Humans
have watched animals come and go for millennia, mystified by what was
going on. The ancients noted that some birds who are common in the
summer are never seen in the winter, but come round once again in the
spring. Since our ancestors tended to stay put in one locale, they
had little idea of where those species of birds went, before they
returned.
One
of the first scholars to speculate on the annual movements of birds
was Aristotle, who—some 2300 years ago—decided that Greek
swallows (who disappeared over the winter) dove into lakes and ponds
and slept the cold months away, buried in mud. He also claimed that
the redstart (an African songbird with a red belly) transformed
itself into a robin (with its red breast) in the fall, then back into
a redstart in spring. Such was the stature of Aristotle that these
beliefs persisted for over 2000 years.
So,
only relatively recently (beginning in the 18th century)
have we come to understand that some bird species migrate
seasonally—primarily seeking sources of food. An insect-eating
thrush spending its summer in New England is bound to starve if it
attempts to overwinter there, so evolution has taught it to fly to
Latin America for the winter, to feast on bugs down there.
The
astonishing feats of many migrating birds have been documented—but
many mysteries remain. They are gradually being solved with
sophisticated scientific studies. The distances they travel boggles
the mind. The Arctic tern flies 20,000 miles from the Arctic to the
Antarctic and back! It's the long-distance flight champion of birds.
The
seasonal destinations of migrating birds is now pretty well known,
through the use of various scientific tracking devices, but many
riddles remain about how birds do it. How does a thrush leave
its hollow in the woods of New England, fly to a certain hillside in
Panama, and return to the same hollow next spring? It is known that
birds use a spectrum of techniques—the Earth's magnetic field, the
position of the sun and stars, landmarks such as rivers and
mountains, even following roads—but specifically how a given
species does it is still being sorted out.
Birds
are not the only migrators, however. Whales seasonally journey up to
12,000 miles, but are tough to follow, since they do it hidden
underwater. The Monarch butterfly travels from as far north as Canada
to one specific mountainside in Mexico.
Then
there are other mysterious movements made by some critters that are
not necessarily seasonal, but still remarkable, in that they travel
significant distances and unfailingly return home. Honeybees use
various landmarks, as well as the sun's position, to return to their
hive and describe to their hivemates the exact location of the pollen
and nectar they've found, using the “waggle dance.”
Recent
scientific studies have shown that pesky garden snails plucked from
the veggies they are chewing on and transported up to 60 feet away,
will navigate back and resume their meal. I learned years ago that a
box turtle we found dining on our tomatoes and then carted several
hundred feet into the woods, would just be back the next morning.
That's a better homing instinct than I have! A few times I've
wandered as little as a half mile into the forest and became
disoriented. Good thing I have never tried to walk to Panama... I'd
never come back!
Tuesday, July 1, 2014
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