Birds: To See Them Is Not to Know Them
There is so much more to the lives of birds than we can see on the surface.
The stunning color patterns of songbirds are also used in communicating threat and individual quality. The common yellowthroat is a little warbler, and males have a Zorro-style black mask and challenge rivals with a ringing witchity-witchity-witchity song. The mask is used as a status signal, and males with bigger masks are socially dominant over other males as well as preferred as mates by females. In some birds, like northern cardinals and house finches, it is the red coloration that reveals so much about the wearer. The intensity of red and orange colors indicates a bird's ability to find and consume foods rich in carotenoids. Eating carotenoid-rich foods does not guarantee a male will have sexy colors, because these chemicals are also used in the immune system. Females prefer red males because only a healthy male can afford the luxury of showing off carotenoids in his feathers.
People who provide nesting boxes for purple martin colonies spend many a lazy evening admiring the acrobatics of their tenants. There is no doubt that purple martins are masters of the sky, plucking dragonflies out of the air with ease and then flying into the impossibly small hole of their nesting compartment at breakneck speed. The martin's long tapered wings and streamlined body say it all: flying machine. The past few years I have collaborated with the Purple Martin Conservation Association to track martins to their wintering grounds in South America--the first time this has ever been done with songbirds. Martins are described in the scientific literature as leisurely migrants, but our birds from northern Pennsylvania typically fly to the Gulf Coast states, across the Gulf of Mexico, and arrive at the Yucatan Peninsula within five days of leaving Pennsylvania. This is a trip of 2,400 kilometers, including an 800-kilometer overwater flight, in less than a week. In spring, most return from the Amazon basin of Brazil (7,500 kilometers) in only three weeks, averaging 350 kilometers per day. When viewing an iridescent black-blue male advertising his nest site with his complex, gurgling song or a female forcibly evicting another who dared to enter her nest cavity, it is hard to believe these birds have just flown from South America. Aristotle was so puzzled by the sudden appearance of swallows in spring that he assumed they buried themselves in the mud to survive winter, much as turtles and frogs do.
Nature literacy not only enriches our own experience of nature, it is also a powerful weapon for conservation and environmental sustainability. Margaret Morse Nice, a pioneering ornithologist famous for her bird behavior studies in the 1930s, wrote in her autobiography: "I thought of my friends who never take walks... "for there was nothing to see." I was amazed and grieved at their blindness. I longed to open their eyes to the wonders around them; to persuade people to love and cherish nature.
She argued that the more we know and understand nature, the more we will care about what is being lost. Although many people do not have the time or means to travel to wild places, the songs, colors, and behaviors of common birds have much to teach us about the wild. The wild in this case is not one of remoteness or exotic scenery but rather of evolutionary adaptation that took place long before humans dominated the planet.
Reprinted from The Rediscovery of the Wild, by Peter H. Kahn Jr. and Patricia H. Hasbach Copyright (c) 2013 Massachusetts Institute of Technology, Published by The MIT Press.