Sunday, June 24, 2012

You Are Not You--Part 2


All this anti-bacterial frenzy ignores the truth that our bodies cannot live without our friends the bacteria. In just the last few decades has science begun to realize the beneficial role of many types of internal bacteria. We’d best learn to call a truce in our bacterial wars, or we’re gonna crash and become part of our own “collateral damage.”

But breeding new species of super bugs is not the only unfortunate fallout of our war on bacteria. Some recent research seems to be pointing the way toward the increasing incidence of autoimmune diseases and other chronic modern ailments. It’s still a mystery exactly why such diseases as Crohn’s disease, type 1 diabetes, multiple sclerosis, and others are escalating, but our blundering is probably involved. We are altering our environment and upsetting biological balances that were built over eons. It’s becoming clear that antibiotics are a significant cause of autoimmune disorders. How?

The driving force behind our immune system is not a self-contained mechanism run by us, but is created primarily by beneficial bacteria. Ever since we became a separate species (about 200,000 years ago), our immune system has been able to tread a delicate balance between being too lax (thus failing to detect and battle foreign pathogens) and too aggressive (and attacking our own cells). Beneficial bacteria have trained our immune system to achieve that crucial balance. It’s not our own DNA that does the job, but bacterial (non-human) DNA. But now we’re upsetting that balance. We’ve saturated our bodies with antibiotics to the point that our immune system is confused and sometimes attacks our own cells.

Another way we mess up our immune system is by not exposing babies to dirt. We’ve become so obsessed with protecting our newborns from nasty bugs that we raise them in as sterile an environment as we can. Meeting a paucity of microorganisms, their immune systems never get a chance to become robust and balanced. This is a particular problem today, as more women are receiving cesarean sections to deliver their babies. The womb is an incredible bug-shielding organ. As an embryo develops from two cells to a trillion, it can safely do so in the womb’s sterile environment—without being turned into some kind of monster by mom’s invading bugs. But to survive in this dirty world, a newborn must very quickly develop its immune system. That process begins as it descends the bacterial-laden birth canal, and continues, as the baby sucks bacterial-laden mother’s milk and inhales Uncle Charlie’s bacterial-laden breath.

But a baby born by C-section immediately pops from a sterile womb into a germ infested world, with no preparation in the birth canal. We aggravate the situation by spraying disinfectant on everything that baby touches. Result: an out-of-balance immune system that goes haywire and either allows otherwise harmless bacteria to beat it down or goes into overdrive and attacks itself.

So the next time your doctor starts to write you out a prescription for a course of antibiotics for some non-lethal infection, you might think about declining. The next time you talk with an expectant mother, you might caution her about the sterile danger of a C-section and encourage her to breastfeed. If neither of these opportunities arises, express a little gratitude for all the friendly foreign critters who make their abode inside you. Your life literally depends on them!

[Note: Some of the information that stimulated this posting is found in the
June 2012 issue of Scientific American.]

Friday, June 22, 2012

Tuesday, June 19, 2012

You Are Not You--Part 1


We are taught by our culture that we are each a unique, separate, and independent individual. We think we are in charge of our mind and body, that we alone determine how our being gets along. We see ourselves as an organism that is assembled from a trillion cells that all have our unique identity stamped on them; cells that make up organs and bone and nerves—every one of them containing our exclusive DNA.

Not so. You are not who you think you are. You are not the distinct “you” that you’ve believed all your life. Instead, you are a colony, a society of countless individuals, a complex ecosystem of creatures that work together to form a vast community. For every single one of your trillion cells that constitute your body, there are ten bacterial cells inside you. These bacteria greatly outnumber the total cellular composite that is you—and they are not just visitors passing through, they live in you! You permanently host a massive colony of beings. You are literally a superorganism. You are not you.

Most of our bodily functions are regulated by these bacteria. Another fable that we’ve accepted is that these bacteria are bad guys—they cause disease and infection. True, some do, but the vast majority are beneficial—in fact, they are essential to our health and welfare. Our digestive system could not do its job without countless kinds of bacteria. They provide nutrients and break down otherwise indigestible food. Our immune system would go haywire without bacteria to regulate it and maintain its exquisite balance. We would quickly expire without the help of all these microorganism critters. We need them, far more than they need us.

Only recently has science discovered the role of bacteria in our biome. (Biome: a large community of creatures occupying a significant habitat—usually thought of as a forest or extensive ecosystem.) We have been obsessed with the kinds of bacteria that cause disease. In centuries past, disease was a mysterious malady whose origins were beyond humans. Then, in the late 1800s, microscopes helped us to see these tiny critters and identify some of them as the source of many illnesses of the day. Shortly thereafter, penicillin and other antibiotics were discovered to have an ability to stop the deadly bacteria and bring about miraculous cures. We fell in love with the drugs that kill microorganisms.

We went to war—fighting many varieties of bacterial infections and rendering humanity far healthier than in the past… or so we believed. In our phobia with conquering bacterial infections, we went a little too far. Today our medical professionals prescribe far too many antibiotics—to the point that the rapidly-evolving “bad” bacteria are mutating into new strains of superbugs that can slough off our most sophisticated antibiotics. We’re literally breeding new kinds of super bugs! Our massive factory farms that crowd together staggering numbers of poultry, pigs, cattle, and fish are wonderful breeding grounds for bacteria, so we dose these critters with copious amounts of antibiotics, hoping that they don’t succumb to disease. When we eat these doped-up animals, we ingest their leftover antibiotics and help to keep the microorganism arms race going in our bodies.

More on microbugs next time…

Thursday, June 14, 2012

A Potpourri of Nests--Part 2


Our local birds construct six different types of nests:
1.    No nest—the whippoorwill and turkey (see photo below).
2.    Cup nest (a coarse outer shell of twigs, lined with soft material)—the hummingbird, crow, jay, Louisiana water thrush, wood thrush, and cardinal.
3.    Mud nest (an adobe-like base that is glued to some sturdy object)—the robin and phoebe.
4.    Tree hole—the woodpecker; followed in subsequent years by smaller woodpecker, nuthatch, titmouse, wren, and bluebird.
5.    Second hand (adapting a previously used nest)—the mourning dove.
6.    In or on manmade structures (including manmade nesting boxes)—the phoebe, Caroline wren, robin, and bluebird.

For many of our birds, the key (as is true for human real estate agents) is location, location, location. Their instincts and learned skills drive their choice of location, but they have little way of knowing what the future may bring. I’ve watched successful broods raised in what appeared to me to be foolish and risky sites. I’ve also watched what seem to be cleverly-located nests that get raided by snakes and other predators. In an attempt to thwart predation, some small songbirds will even nest among raptors for protection, in an attempt to ward off nest raids.

It required a few years of watching, before I understood the nest-construction tricks of the Carolina wren—an especially cunning nest builder. In the spring I have watched a wren hastily throw together some leaves and twigs in an isolated corner (usually under the eaves of a structure I’ve built), thinking I’m seeing its nest being fashioned. A day or two later, I see no more activity, and wonder what happened. Certainly, a predator didn’t already invade. Then I read that the male will construct several “dummy” nests, after which he will escort his mate around to visit the various sites. She will select the one that tickles her fancy and then finish it off. Such a scheme can also confuse a predator, who may be duped into going after an empty nest.

The bird that impresses me most of all in its nest building, however, is the phoebe. To begin with, it always builds under the eaves of our house or an outbuilding, so its nest is rather obvious to us. Even though it’s not a tame bird, the phoebe seems to be quite content to raise its broods right above the doorway. Because their nest may be built against the rafters or under sloping eaves, these can be precarious perches, so the nest must be solidly fastened. They build a strong base of mud pellets, grass, moss, hair, feathers, and phoebe poop—that is cemented in place.

I like to imagine the phoebe to be this deliberate, accomplished carpenter, who carefully examines his selected foundation, and then computes just the right mixture of ingredients, to withstand the rigors of weather and the bouncing movements of family members. Sometimes during the following winter, after the phoebes have flown to the warmth of Central America, I will see a nest come loose and fall, but never during the brooding season. What skill!


Tuesday, June 12, 2012

Turkey nest with eggs

(Dog's head shown for size)

Thursday, June 7, 2012

A Potpourri of Nests--Part 1


As I’ve gotten to know birds better over the years, I’ve come to appreciate the wide variety of nests they build, but especially the artistry that some of them exhibit in their construction process. I’m a slow learner, mostly because bird nests are not easy to find—and that’s exactly what their aim is: to build a child-raising lair that places their vulnerable offspring in a well-disguised place. If nobody catches them in the act, that’s just dandy.

There are many bird enthusiasts who are far more accomplished than I am at locating bird nests. Maybe I tend to respect their privacy a little too much, since seldom have I located a nest in use. When fall arrives, however, I am able to spot a few nests much more easily, after the trees have dropped their leaves. Now and then, during the season, a nest will be blown down by a storm and I can examine the fine handy work up close. It is a special treat, and I always preserve the nest.

Some birds, such as the phoebe and the Carolina wren, prefer to build under the cover of manmade structures, so their nests may be rather obvious. And some, such as bluebirds and chickadees, are happy to move into nesting boxes, so I can locate their nests and later examine them, after they raise their babies. But most birds tend to be secretive about the location of their nests.

Building a nest requires a variable amount of time and energy investment—dependent on how elaborate they decide to go. Woodpeckers put in many hours excavating holes in trees. Their type of nesting carpentry requires a huge investment.

Nests, however, are not absolutely necessary for raising young. Some species drop their eggs on the ground in an obscure location. The ancestors of birds—the ferocious dinosaurs—laid their eggs directly on the ground. The birds, descended from the dinosaurs, grew smaller and became more vulnerable. They learned how to fly. That allowed them to look for more lofty perches for their lodges.

The whippoorwill and turkey are local birds that still nests directly on the ground. The whippoorwill can get away with it, because their coloring is so cryptic that you could almost step on a brooding mom and not see her. I say almost, because she will suddenly flush, just before your foot plops down.

There is also a wide diversity in the way birds go about selecting a nest site. Most nest building falls to the prospective mom. At the least, it’s her choice as to location of the nest. She will spend some time, when her first hormonal pangs set in, shopping around for a satisfactory home site. There is also a learning curve that applies. Mom may not do all that well with her first nest—either in its location or its robustness—but her next nest will probably be better. That can be a reason why the offspring of some species hang around to help mom and dad with subsequent broods: to learn some of the finer points of nest building and baby raising. This is a fine example of cultural learning, as opposed to instinctive actions.

More on nests next time…

Saturday, June 2, 2012

Bear Faced Assault--Part 2


What critter had caused such damage? The only local animal that seems to fit the circumstantial evidence is a bear. Nothing else around here is that big, has such fierce teeth, and goes for those kinds of prizes. We have had neighbors tell us from time to time about seeing bears and other creatures such as cougars, coyotes, wolves, wolverines, and a lion or two. (Where’s the elephant?) We’ve been rather suspect of their accounts—never having spotted anything more fearsome than that old coon. But after 28 quiet years, I guess it may have been our turn. I repeat: there is no proof that a bear swept through in the black of night, but it seems to be the most likely scenario. Not being positive of its identity and reluctant to jump to conclusions, I’ll call it Brutus.

Brutus did not get much sustenance. I hadn’t added seeds to the bird feeder in a few days, so it was nearly empty. A couple of hungry doves could have finished off what was left in a few minutes. Not much of a meal for big Brutus there. Our trash barrel contains only non-recyclable refuse. We compost any tough or inedible vegetable pieces and let the dog clean any food particles from most other items. Brutus at best had an old butter wrapper to lick clean. Pretty lean pickings there. The beehive had been empty for a decade or so—after the last colony was killed off by disease of some kind. Maybe all the destruction was due to a pissed-off Brutus discovering too few goodies to have been worth the work?

Yes, there was one more piece of evidence of Brutus’s spree: Cecil the cat was gone. Although the dogs stay in the house overnight (to prevent them from barking at apparitions in the night and disturbing my light sleeping pattern), the cat patrols nocturnally, hopefully putting fear into the hearts of local rodents. (He stays in during the day, so the birds can flutter around safely.)

And the cat was really gone. A day and a half later, he skittishly reappeared, taking mincing steps and glancing warily about. He’s an easily spooked feline. I can imagine him spotting Brutus and not stopping for breath until he was a county or two away. It probably required a day and a half for him to renegotiate the same route he’d covered in 10 minutes in the dark of night—imagining Brutus hot on his trail the whole flight time.

So what do we do now? I have little interest in offering Brutus any other tidbits, should he return. He got precious little the first round. If he thinks the larder is empty (a bare bear cupboard?), maybe he’ll move on to more rewarding territory… maybe to some of our more imaginative neighbors’ trash. Thankfully it’s spring, so the birds can find sustenance in the burgeoning insect population for a few days, before I try to resurrect the feeder.

A little research on the internet suggested suspending the bird feeder some 9-10 feet above the ground, which should be above the reach of Brutus (if he’s a bear, of course). We moved the trash can into an outbuilding. That ought to keep it safe, behind a sturdy door. Since the beehive offered nothing more interesting than an old mouse nest, Brutus shouldn’t be pondering a return for the long-gone honey.

The best response, I think, is just to wait for a few days, to see if our friend Brutus was making a one-time raid. It’s been 28 years with no such assault, until now. With luck, it may be another 28 years before he (or his offspring) returns. If so, that’d be somewhere near my 110th birthday, so I’m far less likely to have a problem with it.

[Update: I rehung the bird feeder, 10 feet up. Brutus returned several days later, but found nothing more than a bag of sawdust to disturb—leaving an impressively large paw print with claw holes behind. The cat disappeared for only half a day this time.]