Conjecture reigns when interpreting animal behavior
Easily the most studied animals on the planet are we humans. As a species, we've been picked at, poked, and prodded for centuries. You'd think by now we'd know everything there is to know. Yet every day science or medicine seems to announce some sort of discovery regarding the human body and its intricate workings.
This should bring to mind one overriding notion. That is, let's ease up on the silly idea that we have anything more than a hint of understanding of the natural world. A little less hubris is in order. We've got a long way to go. Heck, we're still not sure if coffee is good for us or not.
When we look to organisms other than ourselves, the pages of knowledge blur even further. Sure we can observe and dissect critters but we cannot communicate with them, making the task that much more difficult.
The what's and how's are measurable and fairly apparent. It's the why's that are challenging. That's where we get into a very murky area called behavior. Legions of learned academics continually work to figure out the complexities of human behavior; a person has to clear even higher barriers to explain animal behavior.
There are people who live closer to the natural world than most, giving them a leg up. Farmers and ranchers come to mind. These folks' lives intertwine with the outdoors on a regular basis allowing a more intimate view of animal behavior. Fellows like Heimo Korth - whose life is detailed in the book "The Final Frontiersman" - surely possess a higher insight after spending years in the Alaska bush.
We city dwellers are left with television programs, the Internet, and books to make some sense of the world around us. But even brief forays - either urban or rural - into the outdoors can add immeasurably to our personal knowledge and to our enjoyment.
Just last week my wife and I were sitting in the kitchen finishing the morning paper. In an instant, every bird in the backyard flushed explosively. It wasn't the simple flitting around to adjust position; it was an all out jailbreak. Having witnessed this behavior before, I knew it to be a fight-or-flee response to a threat. I scanned the now-empty yard through the window but saw nothing. But the evidence was compelling enough for me to put my shoes on and venture out the door. Just as I rounded the corner of the garage the little bird-eating raptor flew off, a Northern shrike.
As to the fighting or fleeing, there is a third option taken by some birds and that is freezing. Americans bitterns are known to blend into cattails by standing stock still. Young cuckoos and screech owls exhibit similar behavior. One would assume this ends the game for predators which hunt while seeking motion.
Some behavior is fairly cut-and-dried. We can infer that certain activities can be labeled courtship because breeding takes place in the wake of it. The Western grebe's synchronous water dance is a prime example of pair-bonding and courtship. Another might be the high speed arcs performed by male hummingbirds during mating season. Even the Fargo peregrine falcons engage in an activity viewed as courtship when the male brings food to the female, exchanging it in midair.
How about nest protection? Again, this is pretty straightforward. Anyone who has walked along grassy areas to any extent has kicked out female ducks who flail along as if they cannot fly. And all of us have seen killdeer depart a nest only to display its "broken wing" to any potential predator. In either case, it's safe to assume the behavior serves to protect eggs or young and, by extension, the adult's genes.
Other areas of behavior swirl with debate and end up being populated with educated guesses or pure speculation. Myriad questions remain and will into eternity I believe. Why do some birds hop while others walk? Why do a lot of flycatchers bob their tails? Does the energy expended by wrens building a number of decoy nests pay off with less predation? The list is endless. And until the birds are able to speak a language we can understand, many will likely stay unanswered.