Birds in Modern Life – Ornithology
Birds have been around for over 200 million years. Of perhaps 125,000 avian species that existed during that time, over 11,000 still populate every habitat on Earth except the center of Antarctica and the depths of the oceans. Hominids have been around for maybe six million years, and modern humans only around 200,000 years. But while birds have adapted to the changing environments of the world over 200 million years, humans have changed the environment in a far shorter time.
A century ago, when Americans could expect to live to their mid-50s, the human population was 1.8 billion; today, the world’s human population is nearing nine billion, and an American’s life expectancy is around 80. With the advent of the Industrial Revolution in the mid-18th century, humans started modifying the world by extracting natural resources, manufacturing, ejecting waste onto land and into the air and waters, and covering the land with industrial, commercial, and personal structures.
Largely as a result of this activity, perhaps 190 bird species disappeared in the last 500 years, but 1200 additional ones may be extinct by the end of this century, a major increase in the extinction rate. Today 1,227 bird species are considered threatened, 192 critically endangered.
Are birds being nudged into oblivion due to human activities? Birds with narrow niches and particular food are in trouble. The Giant Ibis of Cambodia, with a population of less than 200 individuals, is declining due to deforestation, drought, and hunting. The almost flightless Kagu of New Caledonia suffers from habitat loss and predation by introduced cats, dogs, and pigs. The plight of the California Condor, on the edge of extinction for decades, is a result of habitat destruction, lead poisoning (from hunters’ bullets) and the high mortality rate of young fed human trash by the parents.
Noisy cities interfere with songs and calls and lights affect breeding and migratory behavior. Cats, windows, cars, power lines, microwave towers, pesticides, and other hazards kill billions of birds annually. Climate change is an increasingly severe problem, especially for migratory birds. And the growing human population usurps ever more resources.
Can birds cope? Some can, to an extent, and some even benefit from human influences. The familiar Rock Dove (pigeon) of cities, the House Sparrow, Barn Swallow, and European Starlings have adapted well to human environs and occur in 80 % of the world’s urban environments. Estimates indicate that maybe 20% of the world’s bird species visit or inhabit cities. The Common Mynah, European Blackbird, Marabou Stork, as well as many species of waterfowl, gulls, and parrots have made themselves at home around humans. They nest on building ledges and bridges, roost in airport hangers, oil refineries, and barns, and eat scraps or agricultural crops. Some populations of city birds are actually healthier and have more offspring than their woodsy brethren. At least a few songbirds have changed their tune (literally) to be better heard over the cacophony of the city. And some have even learned to cope with fast highway traffic.