Contemplating Critters

     I recently took an online course in animal behavior from a Dutch university. As part of the lessons, we were asked to develop our observing skills by spending at least 10 minutes watching an animal. We were encouraged to take notes and to be as detailed as possible. I pondered how I might take on this assignment, given that many of my local animals would be very unlikely to stay in one spot for that long. I also felt that if I got too close to a critter, my presence would alter its behavior, and thus my observations may not be representative of it or its species.

        I love to watch birds at the feeder—which gets lots of avian traffic, but rather than stick around, each bird flits in, grabs a seed, and flies off. There's no chance of watching it for more than a few seconds. I could possibly watch a specific bird over several minutes, as it repeatedly returns to the feeder, but I can't tell one individual bird from another, so I might be seeing several different individuals.

So that brings up a question: If I were able to watch one critter for 10 minutes and wrote down my observations, how indicative of the species' behavior would that individual be? Maybe instead I could learn something about bird behavior by watching many different species of birds come to the feeder. That's one of my favorite activities anyway.  So maybe I could learn as much about animal behavior by contemplating groups of them, rather than just one.

Well, I've done this for several years now and have noted the varying behaviors of a number of different species. For instance, chickadees and titmice fly in, grab a seed, and fly to a perch, where they lodge the seed between their feet, and then bang away, breaking through the shell for the meat inside. A dove will sit at the feeder, downing one whole seed after another. A finch will pick up a seed and crack it with its powerful bill, and pick out the meat with its deft tongue. A Carolina wren will squat in the middle of the feeder, fastidiously poke at one seed or another, tossing away all but the fattest ones.

These observations have shown me over years how one species of bird behavior at the feeder differs from another species. But even within one species I see differences. For example, that goldfinch there was behaving much more aggressively than the others. That cardinal seems uncertain and slower than the others. That chickadee was far more meek than the others. That titmouse just challenged and chased off a wren, when most of the other titmice wouldn't have dared.

So what do I think about these individual differences I see? Which behaviors are species-specific and which are just the peculiar behavior of that individual bird? Like most of my observations of nature, I soon see a far more complex picture than at first. I guess I've no alternative but to put in a few more years of observation time.

Brimful Bill

 How many of us have had our parents exhort us not to talk when our mouth is full? Not only is such behavior bad manners, but our speech can become quite unintelligible, as food gets in the way of our tongue and lips, as they try to perform their nimble job of shaping sounds. Our speech and song is produced by the vibrating vocal cords in our larynx, which is then modified and shaped by muscles in our throat, nasal passages, tongue, and lips. It is a complex process that allows us to create a very wide variety of utterances. It gives rise to many kinds of sounds.

Several years ago I watched a goldfinch at the bird feeder, filling its beak with seeds, crunching the hulls off, as it shifted the particles around inside its beak, with its dexterous tongue. As I was watching, I heard a goldfinch song and looked around to see if another one was nearby, but the one at the feeder was the solitary goldfinch in the area. It dawned on me that this bird was singing at the same time that its bill was full. It seemed as if it had violated the etiquette of not singing with a stuffed bill; yet its song—unlike what emanates from a human's full mouth—was clear and clean. What was going on?

A visit to my bird books soon gave me the answer. A bird's song is created in its syrinx (analogous to our larynx), which is situated well down its throat, at the entrance of its two windpipes (tracheae). At the junction of each side of the syrinx and its adjacent trachea are a set of tiny, complex muscles. Vibration of thin membranes (like our vocal cords) creates sounds that are then manipulated and altered by these muscles. A bird's throat and mouth muscles play no role in its song—hence they can independently do their feeding job, without interfering in their singing.

This song mechanism is quite amazing. Virtually all of the air exhaled through a bird's syrinx is used for singing. In contrast, we humans use only about 2% of our lung air in vocalizing—which is why these little critters can sing so fully and loudly. Furthermore, a bird can literally sing a duet with itself, as air exhaled from each windpipe flows across the muscles on each side of its syrinx. The complex song of a thrush is an example of this self-duet. Two songs at once! In fact, a bird is even able to vocalize through one side of its syrinx as it breathes through the other. That beats the feat of a human ventriloquist!

All mammals are outfitted with a larynx, rather than a bird's intricate syrinx. I guess that means all mammal mommies urge their children not to speak with a full mouth? What other kinds of lessons of etiquette do bird mommies teach, when their kid's bill can be full to the brim and still sing out clearly and beautifully?

Big Bad Bird

I've written before on the pecking order that birds establish at our feeder. Certain species of birds dominate or intimidate other species, in order to get first dibs at the feeder. Most often, the hierarchy appears to be determined by the relative sizes of the birds—but not always. While the larger cardinal will invariably dominate the smaller titmouse or chickadee, the smaller goldfinch will easily chase off the larger titmouse.

How can the more petite finch intimidate the bigger titmouse? I doubt that the small finch is conscious of its more diminutive size, since I would guess that most birds have no comprehension of how large they are. If they can't recognize themselves in a mirror (which they adequately demonstrate by pecking at their own reflection in a window), how can they have knowledge of how large they are, relative to another bird? It's got to be more than size.

In the case of a goldfinch facing off a titmouse, even though the former is smaller, its bill is far stronger. The finch can crush a hard seed with its tough beak, while a titmouse must lodge the seed in its claws and bang away repeatedly with its weaker bill, until the seed yields its hard shell. If the two of them were to engage in a battle for pecking order, the smaller goldfinch could deliver a painful bite that the titmouse would long remember. I think that Nature has built into the titmouse an innate knowledge that it would be foolish to challenge the finch. So the safe thing for the titmouse is to defer to the finch, wait, and go for a seed after it has satisfied itself.

The term pecking order comes form the jostling that occurs between barnyard hens, as they establish their hierarchy. The chickens' process must be different from songbirds, however, because chickens are one species, are similar in size, and in beak force. Their pecking order seems to be determined by experience; by conflict. It can be a rather vicious process to watch, but once the chicken hierarchy is resolved, relative peace reigns. For them, it’s not a case of an instinctive response, as it is for songbirds. Chickens learn it; songbirds inherit it.

On rare occasions I have observed a lower-order bird challenge a superior one, at the feeder. Aha, I think, it’s going against its inherited tendency! Something interesting is happening here. Is the normally less-dominant bird ignorant of its place in the pecking order? Is it foolishly taking a chance? Maybe it just accomplished a feat that required unusual bravery and is high on its audacious stunt? In these cases, sometimes the challenger wins, but I suspect that it will later come to its senses and once again defer to its evolutionary overlord, at its next trip to the feeder. Evolution does prevail, in the long run. The pecking order is perennial.

Fortunate Fowl

We have been feeding our local birds for several years now. I've written before about my questions of whether this practice is good for them or not. On the positive side, we offer them sunflower seeds, which are packed with fat and nutrients. We've observed our local birds sometimes parenting three broods in the summer—which is a good indication they are healthy. On the negative side, it's possible to spread disease if the offered food becomes contaminated. In addition, the feeders can attract hawks. All in all, I've concluded that feeding our birds is helpful to them. The readily available high-quality food gives them quality nutrition and we've noted few hawks coming around.

We have a contingent of birds that reside here all year long, and constantly partake of our offering of seeds. There are other species that migrate through from time to time—stopping to fill up on the offered goodies, before they continue on their travels. 
 
I sometimes wonder, however, about another possible impact of feeding our local birds: Might we be contributing to their laziness? Birds who inhabit the surrounding deep woods must work far harder to feed themselves, than our fortunate fowl. A bird must consume a large number of calories each day, in order to survive. The expression “eat like a bird” suggests that they consume a modest amount of food, but if they weighed as much as a person, they'd need to eat over 6,000 calories of food every day!

So our pampered birds definitely have it easy. They can devour their daily intake in a fraction of the time that forest birds do. A few minutes at the feeder and then they can goof off the rest of the day. I wonder what they do with all that leisure time. Do they make productive use of it? Do they just lounge on their perches, or do they engage in fruitful activities? Do they discuss bird philosophy? Do they get involved in art projects? Are they at all appreciative of the golden opportunity they've been given and thus devote time to the loftier pursuits of life, or to helping their fellow birds? Or are we just contributing to their indolent lifestyle?

Then I worry about making them overly dependent and helpless. What would they do if we went away for a couple of weeks in the dead of winter? Could they survive without their daily alms? Have they lost the ability to take care of themselves?

And there's yet more to worry about. Wild birds dine on a variety of food sources—seeds of all sorts, bugs, plant material, etc. Are these wild cousins getting a more balanced diet and thus actually healthier in the long run? A fare of exclusively sunflower seeds may not be giving our local birds the balanced nutrition they require. In the summer they can supplement our offerings with bugs and thus ingest a variety of protein, but in the winter they dine on a monotonous diet.

Oh, what tangled webs we weave, when first we ask them to receive... our humble offerings. The ramifications of a simple act of generosity can be so complex. Maybe I should go consult and avian nutritionist.

Goldfinch Gallivantings

We have three kinds of birds that visit our feeder: (1) year-round residents who come most every day for a snack, (2) year-round residents who periodically come and go, and (3) migrants who we see either temporarily residing here through the summer or winter, or just passing through in the spring or fall.

American goldfinches fall into the middle category above: we may see them visit the feeder at all times of the year, but only for few days. A flock of them will hang around for a while and then disappear for a few weeks—to return again. (At least I believe I'm seeing the return of the same group, although it's possible that I'm seeing a new flock of finches each time.)

I call the goldfinch a "periodic" resident, because it doesn't leave for Central America for the winter or head north to Canada for the summer. We'll see them at all times of the year, but, as I wrote above, it has the interesting habit of hanging around the feeder for a few weeks, and then disappearing for a month or so. Goldfinches engage in what ornithologists call "irregular seasonal movements," which finds them roaming in groups—their current territory being determined by the availability of the food supply they find there.

Okay, so they are resident roamers. That fits my experience, as I see them come and go from time to time. But why leave for a spell, apparently seeking new sources of food, when I put seed out all year long? The other regulars at the feeder dine on the continuously-offered sunflower seeds—supplementing them with bugs; a good source of protein. Do the goldfinches get tired of sunflower seeds and wish to change their diet occasionally? I could buy special finch food (they love thistles), that might entice them to hang around, but that option gets kind of pricey for my wallet.

Ornithologists have a difficult time tracking the roaming habits of any type of songbird—especially the little guys like goldfinches. Most any radio tracking device is too heavy for them to carry around, so their roaming habits are not yet well understood. (Although this is another ornithological barrier about to be cracked, as new, ultralight transmitters have been developed and are being deployed.) Thus, I have no idea where our finches go when they depart, how far they roam, or even if the group we see is the same one. When I see a flock appear at the feeder, I wonder if it is old friends returning or new visitors coming in for a temporary feed. Maybe I'll figure this out before long.

It's another one of those mysteries you constantly encounter, when you come to observe closely the natural world's goings on. If you don't take the time to watch, you rarely notice these intriguing details, and you're unlikely to become interested enough to ask the questions that occur to you, once you do begin to pay attention. When I observe closely, I find that many questions begin forming a long queue in my head. I love it! It's what adds endless interest to my life, way out here in the woods.

Feeder Foes

I wrote last time about a sharp-shinned hawk attack on cute little chickadees at the bird feeder. The battle for life often finds one kind of critter killing another for food. Songbirds—when they’re not gorging themselves on the sunflower seeds that I put out—will eat small spiders and other bugs. The insects’ death ensures the life of the bird. In turn, a hawk catches and kills a small bird (or rodent), which ensures the life of the raptor. We humans may rue the death of an adorable songbird, but care far less about the death of a yucky bug.

The chickadee needs lots of fuel in the winter (as does the hawk). Half of all the calories that the little bird eats goes solely into shivering, which generates heat in its tiny body (about a third of an ounce, or the equivalent of two nickels).

Nature has given the songbird an exquisite sense of sight. We humans need binoculars to begin to rival their ability to spot tiny crevices in tree bark, where a bug may be hiding. They can also see into the ultraviolet range—allowing them to spot numerous food items (bugs) that may be tinged with a little UV coloring. These enhanced abilities help keep them alive through a bitter winter. Even so, many of them starve. (That’s why I feel that my bird feeder helps—by offering sunflower seeds loaded with fat.)  

The songbird foe, the sharp-shinned hawk, also has his imposing skills. His eyesight is even better, though not as keen as his larger family members—such as eagles. The “sharpie” is the smallest hawk—about the size of a blue jay. Many people who feed birds hate this small hawk, because it will lurk in a tree or bush—watching “like a hawk”—and suddenly burst out to snatch a cute songbird. Mother Nature’s wisdom, however, exceeds ours. The sharpie is actually useful in culling less fit birds (thus keeping the remaining flock healthier), as well as training them to be alert and wary. Wolves serve a similar function for deer, antelope, and other browsers.

Like other fierce-looking members of the hawk and eagle family, the sharp-shinned hawk has a hooked beak, strong feet, and curved talons, for seizing and killing prey. Its crown and back are a dark, blue-gray color, while its undersides are a beautiful white-and-rufous barred pattern. Its wings are short and wide and its tail is long—giving it the ability to make quick turns in its dash after prey. It is a migrating bird that breeds up in Canada and winters around here and farther south.

I feel constantly torn between the success and well-being of these feeder foes; but the success of one comes at the sacrifice of the other. I can’t have it both ways, nor does it make sense for me to favor one over the other. Nature doesn’t. It’s a balance. Maybe I can come to accept nature’s way, without casting my lot with either?

Hawk Attack

For years I have fed songbirds at the feeder. It seems like the right thing to do and it’s fun to watch the antics of the little guys, as they cluster around the feeder holes, vying for access to its cornucopia. I know I’m offering them vital nutrients in these cold months, but I’ve also been concerned about predators attacking them and how I may be setting up the little guys.

A bunch of tasty morsels crowding around the feeder must create a tremendous attraction for hawks. I have suspected that sharp-shinned hawks might be lurking in the vicinity. I’ve read that they are a major predator around feeders, but had never spotted one…until a few days ago.

There have been numerous occasions when I’d notice that all the songbirds near the feeder had instantly transformed themselves from jerky little acrobats who were constantly on the move into feathery statues. It was as if some magic hand had waved and suddenly turned them into taxidermy figures. For several minutes the only move they’d dare make was an occasional blink of an eye. My guess is that a hawk had entered the arena and they knew that their survival lay in stillness. I never was able to spot a hawk, however, and soon the little guys would resume their furious activity.

It can be crucial to the survival of a tiny songbird to ingest a sufficient amount of food energy, especially on cold days. Their tiny bodies rapidly radiate heat, so they must eat an enormous amount to stay alive. The expression to “eat like a bird” is very misleading. They gorge themselves. A tiny chickadee requires some 16 calories a day. Now, that might not sound like much, but scale that bird up to a 150 pound human, and you get the equivalent of over 6,000 calories! Try eating that much every day and still try to fly—let alone waddle across the room!

In order to gobble up that many calories, a little songbird in the wild must be scouting for food nearly every waking hour. It needs to find several hundred bugs a day to survive. On a cold January day, that’s an overwhelming task. If, instead, the bird has access to a feeder that is stocked with black oil sunflower seeds, just a few dozen seeds a day provides all the nutrients it needs. It’s in bird heaven!

So I’m helping the little songbirds survive the harsh winter. But am I also setting them up for a hawk’s meal? Maybe so. As yet I haven’t actually seen a hawk, nor any tell-tale pile of feathers on the ground—signaling the remains of its birdie feast. I also know that many songbirds gathered together provide each other a degree of safety, since many eyes on the lookout can spot a foe quicker than one pair.

A few days ago I was finally witness to a spectacular hawk attack. I happened to be standing still near the feeder, when there was a sudden flurry of activity in the trumpet vine next to the feeder. I looked over to see a sharp-shinned hawk dive repeatedly at two chickadees who were receding as fast as they could into the protection of the vine’s branches. The much larger hawk could not get in to grab them, though he tried several times in the split second I watched the attack. It then spotted me and streaked off to a nearby tree, where it landed on a limb and balefully eyed me, as if resenting my interference.

I inched slowly toward the hawk, hoping to get a better look. What a beautiful bird! It turned its back on me, unceremoniously pooped, and flew off into the forest—leaving me trembling in wonder. Wow! I was torn between a sense of relief that he failed in his attack (my birdies were safe for now) and knowing that this beautiful raptor needed to eat too.

I regretted not having a camera at the ready, but so many of nature’s gifts that I receive pass too quickly for a photo. I may not have captured a picture of this delightful bird, but the vision is surely permanently seared into my memory. I was graced.

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 110^th 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.]

Bear-Faced Assault--Part 1

For 28 years we have lived in the northern Shenandoah Valley and (knocking on wood) have never been attacked by anything more fearsome than a fat old raccoon—and he was more confused than threatening. (I think he got lost on his way to his girlfriend’s den, one spring morning.) Upon moving out here from the city, urban friends imagined all sorts of invasions that thankfully never came. What sort of invasions? Dastardly things, such as motorcycle gangs, pumas, wolves, vampires, and a stray sasquatch or two. Life has been pretty tame here though, with garden-raiding deer the major menace so far.

So far, that is, until a few nights ago. Shortly after rousting from bed one morning, I peered out the window to see what birdies might be at the feeder, to be greeted with the sight of it in strewn in pieces on the ground. Normally, it hovers about five feet above the grass, swinging safely above leaping squirrels and raccoons—saving its offerings for songbirds. The damage was far more than just a suspension cable somehow snapping and dropping the feeder to the ground. It looked as if it had been savagely disassembled with a sledge hammer.

I let the dog out, to investigate the scene of the crime, while I threw on some clothes. I watched him gingerly sniff over the debris, spookily jumping every few moments, as if the smell of something frightening lingered in the air. Convinced the coast was most likely clear, I followed the dog out. Something big had visited in the night… big enough to reach up, tear the feeder apart, and pull its remains from its perch. Not a seed was left.

Deciding to patrol the area for other possible evidence of vandalism, I next saw the trash can on its side, with its once neatly-ensconced bags torn asunder and scattered over the yard. Looking closer, I noticed two significant holes punctured in the can’s heavy plastic sides, as if some large mouth with piercing teeth had wrestled with it and won. The can’s twist-lock, “secure” top had been untwisted, unsecured, and cast aside.

Looking off along the trail of trash into the woods, I saw the beehive toppled from its perch and busted into several pieces. The dog continued to sniff the scene, jumping back every few moments. His nose and my eyes were painting an intimidating picture.

More on the attack next time…