CONSERVATION

The primary reasons for declining populations of birds across North America are the loss and degradation of many of their habitats. This has been caused largely by human activities; development, modern agricultural methods, over harvesting of natural resources, and pollution are among the serious threats to natural habitats across North America.

There are well-documented examples of birds that have suffered steep population declines as a result of pollution. Peregrine Falcons were reduced almost to extinction in the middle of the 20th century because of eggshell thinning caused by the pesticide DDT. Hundreds of thousands of seabirds (and other marine animals) have been killed by oil spills from large tankers. Loons and other northern-nesting species declined precipitously from the effects of acid rain, which has damaged forests and wetlands in the Northeast.

The banning of DDT in 1972, as well as of other organochlorine pesticides in the United States, led to the recovery of many bird species from near-extinction. But such pesticides are still legal in other parts of the world, including some parts of South America where many North American species winter. And in the United States and Canada, intensive use of other pesticides by the agricultural industry has resulted in death and severe genetic damage to many vertebrates.

Following is a general discussion of conservation issues of some habitats in North America and how they affect bird populations. In addition, the introduction to each bird group notes conservation concerns, and a list of bird conservation organizations appears below, in this Resources section.

Forests— Harvesting, fragmentation, and degradation of forests have caused severe declines in many bird populations. For example, in the Southeast, Red-cockaded Woodpeckers are endangered, largely due to the loss of old-growth pine forests, and Ivory-billed Woodpeckers, which once thrived in old-growth lowland forests, may be extinct (sight reports of this species still exist). A subspecies of Spotted Owl that depends on the rapidly dwindling old-growth forests of the Pacific Northwest is listed as threatened. Countless woodland birds are negatively affected by heavily fragmented forests (which are unsuitable for species of interior woods) and by replanted woodlands that lack the diversity of natural forests. Strip-mining, mountaintop removal, and construction have replaced woodlands with human-modified environments useful to only a minority of bird species.

Prairies and grasslands— Most of the vast prairies that once covered central North America and teemed with birdlife were converted to agricultural use more than a century ago, and modern agricultural practices, including applications of toxic pesticides, herbicides, and rodenticides, continue to degrade the few remaining native grasslands of the Great Plains. Likewise, the more aggressive methods of modern cattle ranching have destroyed vital riparian corridors and open-country habitats and have encouraged the rapid spread of invasive plant species, degrading and destroying habitats used by prairie-chickens, sage-grouse, and other birds.

Wetland and ocean habitats— Agricultural activity and development in North America since colonial times have resulted in the draining of tens of millions of acres of freshwater wetlands, and many populations of waterfowl and other species that rely on these habitats have plummeted perilously over the years. It was not until the early 20th century that American governments began taking measures to preserve freshwater wetlands; but these habitats are still quite endangered and fragile, beset by pesticide and fertilizer pollution, drought, and invasive alien species. In coastal areas, development has forced colonial water birds and many shorebirds into smaller and smaller breeding areas, and these are subject to frequent disturbance by recreational boaters and beachcombers. Offshore, a staggering array of pollutants—abundant garbage discarded at sea, mercury and other heavy metals, and oil spills—plague seabirds and marine mammals. Seabirds also suffer from the over fishing of key prey species, and thousands are killed in gill nets and on long-lines. Some populations, especially of larger tubenoses, are declining at alarming rates.

Global warming— The burning of fossil fuels to produce energy has produced excessive carbon dioxide in the atmosphere and caused the gradual warming of both atmosphere and oceans, a phenomenon commonly referred to as global warming. The consequences of this to birdlife (as well as human life) could be catastrophic in the relatively near future. Already in the Arctic—where the polar ice cap is melting and sea ice is much less extensive than in decades past—there are signs of ecosystem collapse. The rise in sea level predicted to occur in fewer than 100 years could eliminate the Florida Everglades, along with many islands, beaches, and salt marshes used by millions of nesting birds. Rising temperatures would radically alter many other habitats and allow tree diseases and insects to invade regions previously too cold for them. Global warming has already resulted in outbreaks of tree pests, severe forest fires, and the invasion of shrubs into what was once tundra—breeding habitat for dozens of bird species.

Getting Involved in Bird Conservation — From the earliest days of the conservation movement, birders have led the way. They have worked to protect birds’ habitats, protest unsustainable killing of birds, and fight the poisoning of the environment that led to near-extinction of many species we now take for granted in North America. Populations of Bald Eagles, Peregrine Falcons, Brown Pelicans, and many other birds have recovered, but there are still hundreds of species faced with declining populations and habitats.

Birders seeking to contribute to bird conservation should join the National Audubon Society and other bird conservation organizations, read their newsletters and magazines, and watch for opportunities to help out locally or beyond. At the local level, bird clubs and Audubon Societies are always active in wildlife-oriented activities and in legislative initiatives. It can be extremely gratifying to work within these organizations to help create or preserve local habitat, build nest boxes, or raise money for bird conservation. Taking action on the national or international level may consist of participating in letter-writing or fund-raising campaigns, lobbying efforts, or even education and outreach projects in distant parts of the world.

Simply going out and watching and identifying birds—as well as counting them carefully—can contribute to a whole host of citizen-science projects that are maintained on Web sites. Long-term projects on the Internet include:

eBird —www.ebird.org (The Audubon Bird Guide app links to eBird and is an easy way to download your sightings to eBird.)
Christmas Bird Count —www.audubon.org/bird/cbc-mbr-pwrc
North American Breeding Bird Survey —www.mbr.pwrc.usgs.gov/bbs/
Project FeederWatch— www.birds.cornell.edu/pfw