Most songbirds don’t live more than a year or two. Half of them die in the first year. That survival rate has been good enough to keep birds on the landscape for about 60 million years in one form or another.
What exactly was the first bird is debated, and the answer relies to some extent on the good fortune of actually finding evidence. That link might still be buried somewhere.
The transition from dinosaur to bird was neither quick nor clean. Many early models were scrapped as improvements evolved. Sort of like airplanes.
The first — and still the most famous — animal proclaimed to be a bird is Archaeopteryx. It had feathers, but also a scaled tail and teeth. It was one of many feathered transitional creatures; not quite birds, but working on it.
I always thought Archaeopteryx, companion to dinosaurs, was big, swooping on leathery wings through fern-filled forests. Actually, it was the size of a raven, about 20 inches long, weighing maybe 2 pounds. Not Jurassic Park. Sort of disappointing. The first Archaeopteryx fossil was found in a German quarry in the 1860s.
The history begins 60 million years ago just after the extinction event known as K-T. Scientists speculate on the cause: a huge comet striking Earth in Mexico or massive volcanic eruptions on the other side of the world. Either way, the world’s air was filled with debris for a long time. Most large creatures died.
Left to themselves, small animals like birds thrived.
At that time, many modern orders of birds began to appear. (Birds that perch, as a group, are an order. Waterfowl form an order.)
The following 20 million years brought the greatest diversification of bird species.
By 50 million years ago most of the bird orders we know today had appeared. The Cornell Lab of Ornithology Handbook of Bird Biology says at this time shorebirds, flamingo-like birds, and birds like rails and cranes were abundant.
During the next 20 million years, the order passerine — the songbirds, our feeder birds — evolved. In the following 15 million years these birds “diversified explosively,” according to Cornell.
By the time early humanoids appeared, 200,000 years ago, most modern bird species had evolved.
From fossils and DNA evidence, scientists have established the timeline for development of the bird family. DNA evidence has been important because fossil evidence is rare. Delicate creatures, birds are far less likely than large animals to leave remains that fossilize.
If, however, the birds died in very particular places, fossil evidence can be found.
One of those places is called Fossil Lake, in Oregon, termed a bonanza of Ice Age fossils, including saber-toothed tigers, mammoths and many bird species. Newest fossils there date to about 15,000 years ago, late Pleistocene, the Ice Age era.
Early finds at Fossil Lake included bones of at least 74 bird species, according to old research reports. Some of those species are extant, while others show evolutionary changes or are extinct.
Findings included evidence of grebes, swans, geese, many duck species, storks, herons, gulls, terns, sandpipers, vultures, grouse, turkeys, flickers, jays, larks, crows, ravens, blackbirds and owls.
There were smaller birds, as well. The man who studied these fossils, an ornithologist named R.W. Shufeldt, said those smaller birds could not be identified.
I know about that.
Read Jim Williams’ birding blog at startribune.com/wingnut.