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.

Human Brainpower Bested

Sometimes I think we humans suffer from deep feelings of inferiority, because we so often tout reasons for our being best, or belonging to the better group. It's as if we are trying to convince ourselves of being superior, by expressing that my religion is better than yours, my team is number one, my kid is at the top of her class, and other such bolstered beliefs.

We especially fall into this game of snobbish notions when we compare humans to animals. Several hundred years ago it was an unquestioned conviction that we were absolutely superior to animals. We had utter faith in the divinely-created hierarchy, that placed God at the top, angels and other celestial beings next, humans next, and all the animals at the bottom. The major source of our supremacy was believed to be our brain—clearly larger and more complex than any other critter. And look around you... don't we dominate the planet? Is that not proof that we are number one?

That sense of superiority has been hard to deflate, but science has gradually been chipping away at our edifice of arrogance. Recent research is discovering many ways in which features of some animal brains, in fact, best ours. Here are a few examples.

Neurogenesis is the process of growth of new neurons, and thus compensates for the loss of neurons as a critter ages. Only in recent years have neuroscientists shown that we human oldsters do indeed create new neurons—though we get increasingly slower at doing so as we age. Yet we're bested by several animals, including some species of fish, who perform neurogenesis about 100 times faster than we do.

Secondly, we pride ourselves on our good memories, but chimps do much better at remembering. So do some species of birds and squirrels, who stash thousands of seeds in times of plenty, and then remember the locations, months later.

Thirdly, our sense of smell—a key brain function—is quite inferior to many animals, because that part of our brain (the olfactory bulb) devoted to smell is relatively small. A bear's olfactory bulb is five times the size of ours—even with a brain that is one-third the size of ours. The super smellers—sharks--devote one-third of their entire brain just to detecting smells.

Fourthly, our brain weighs about 2.5 pounds (1.2 kg). That is quite large, compared to our ape cousins, but a dolphin's brain weights 3.5 pounds (1.5 kg). And we are dwarfed by elephants and whales, whose brain weighs 11 pounds (5 kg). Now, brain size is not the sole governing factor... the brain-to-body mass ratio is a better measure, but even there we are overshadowed by our ocean-dwelling cousins.

Fifthly, without our GPS software on our smart phones, we are lost. Many folks today cannot even make use of a map.  Birds—especially pigeons—possess brain cells that are sensitive to the Earth's magnetic field. Rain or shine, sunny or nocturnally, they know their geographical location.

There are several other examples of how animal brains surpass ours, but that’s a good overall view. We may be the smartest (when is the last time you read about a pigeon winning at Jeopardy!?), but we trail animals in many brain functions. It might be useful for us to cultivate a little humility and recognize those brain functions where we are bested by the beasts.