Trip Report
Dan Gleason’s "The Joy of Birds" slide presentation was a veritable collage of color, texture and behavior. We were smitten with pretty birds on seashores or ruddy desert landscapes, or choreographed in elegant and graceful flight. As guaranteed, Gleason described the "many pleasures we derive from birds and birding." And he also included examples of the many ways centuries of artists have depicted birds. Objects of fascination across cultures, birds grace Italian frescoes, ancient coins, Japanese fans, and totem poles - with regal, whimsical, even menacing bearing.
But then Gleason, a respected field ornithologist and retired UofO biology instructor, described their adaptive behaviors and structural morphology, and we were mesmerized by the tiniest of physical details in beaks, glands and lobed toes, structural details our avian friends depend on for their livelihood and survival.
Take beaks, for example: They come in a variety of shapes and sizes, depending on where the bird gathers its diet, and whether it dines on seeds, insects, fish or carrion. The pelican uses his lower jaw and pouch as a fishing net. The pouch widens as he dives underwater. Once the fish is caught, he drains the water from his pouch, tilts his head back and gobbles down his supper. The great blue heron has a very long, sharply pointed bill used to spear fish. And, the bill of a tufted puffin allows it to hold onto many slippery fish at a time, sometimes lined up neatly in a row. And, by the way, the tufted puffin molts the top layer of her colorful beak every summer after the chicks have fledged, marking the end of the breeding season.
Not all feathers are created equal: Cormorant feathers are not naturally waterproof. In order to make deep underwater dives, the cormorant wets the outer layer of its feathers, reducing buoyancy and allowing it to pursue prey. To dry its feathers, the cormorant perches and spreads its wings toward the sun. Unlike other seabirds, cormorants do not venture far from their nesting colonies, which are built either on offshore rocks, ledges or islands. Cormorants build nests from sticks and whatever else they can find. When its neighbor isn't looking, the cormorant isn’t above stealing nesting materials!
Another seabird, the common murre, lives in tightly knit colonies on rocky islands or cliff edges. It, too, is a creature of habit, coming back to the same spot year after year. They don’t build a nest. Instead, the female lays a single egg, held on the top of her feet during incubation. Common murre eggs are variegated in color and pointed, so if disturbed they roll in a circle rather than fall off the ledge. Seabirds have specialized salt glands above their eyes, which prevent their bodies from over-salting. The glands produce a salty solution that is excreted through the birds’ nostrils and down grooves of their beaks, where it drips off.
With huge nostrils and bald heads, turkey vultures aren’t especially attractive. But there’s much to be admired about these threatening-looking creatures. For one thing, the turkey vulture is among the few birds which have a fine sense of smell for detecting the odors of dead animals well below the forest canopy. The turkey vulture consumes and then regurgitates food for its young; never taking live prey to the nest, keeping the home front neat and tidy.
As far as backyard birds are concerned, the northwest black cap chickadee sings the familiar chick-a-dee-deedee, but with a slightly different nuance than other chickadees around the country. And, those jays we see are stellar and scrub jays, not blue jays. While jays east of Colorado have blacker heads and crests with whitish streaks and a white spot above the eye, our backyard jays have forehead feathers tipped with light blue and whitish streaks on the chin and throat.
Lastly, Gleason described the plain-looking starlings as "the bird everyone loves to hate." They are aggressive and annoying - but interesting, nevertheless. Like the turkey vulture, the starling has an acute sense of smell. The starling also "ants actively;" which is to say he pecks up ants and rubs them over his feathers. Biologists speculate the acidic ant secretion contains chemicals that act as an insecticide or bactericide for the bird; or, these secretions supplement the bird's own preen oil.
Such descriptions were among the many Gleason offered in his presentation. The main point left with us was: "Keep your eyes open. There are all kinds of exciting things in the world.
