The State of Birds
Since the year 1600, at least 131 species of birds have gone extinct. Most of these were island species that fell to...
The International Union for the Conservation of Nature (IUCN) maintains a Red List, which classifies species depending on their risk of extinction. (The IUCN Red List can be found here.) In 2006, the Red List identified 532 bird species as endangered and 674 more as vulnerable.
The IUCN Red List categorizes species into the following groups...
The criteria for these levels can be found here.
In North America, about half of the bird species are declining (208 out of 414), some at rates as high as 10 to 15% annually. At the same time, 118 species (28%) are increasing and 88 species (21%) are stable.
Among those species in most serious decline (in N. Am.) are grassland species, such as Eastern Meadowlarks, Loggerhead Shrikes, Greater Prairie Chickens, and several species of quail.
Farmland specialists have declined due to the replacement of farmland with modern agriculture. The increased use of herbicide and pesticide, in conjunction with monoculture farming (growing only one crop) eliminates major sources of food for resident birds: weeds, insects, and leftover grains/plant material.
Birds that live in scrub lands and young forests (as well as old fields and abandonded farms) are declining as these habitates are converted to suburban areas or as forest mature and the ecosystem changes. American Woodcock, Eastern Towhees, and Golden-Winged Warblers are examples.
Birds that adapt well to man-made habitats are doing well. These include Common Pigeons, Common Starlings, and House Sparrows. Canada Geese have adapted to golf courses; Osprey nest on powerlines and telephone poles. Red-Tailed Hawks and Cooper's Hawks are adapting well to cities, as are American Crows. Even Turkey Vultures are benefitting from increased roadkill.
The growing human population pose both direct and indirect threats to native bird populations. These include...
Domestic house cats in N. Am. kill hundreds of millions of birds each year. Farm and barnyard cats kill approximately 39 million birds each year. Millions of feral (wild) cats add to this. The solution: keep pet cats indoors. Benefits include...
Collisions & Conservation
Healthy populations of birds produce a surplus of young each year. At least half of the total number of birds in N. Am. die each year, as part of their natural cycle. So, many species are able to compensate for the losses. The exception is large, slow-reproducing birds (cranes, condors, albatrosses) that can't reproduce fast enough to compensate for yearly losses. (Such as when large numbers of albatrosses drown after being hooked by commercial fishermen.)
Conservation generally focuses on populations rather than individuals. Conservation problems arise when breeding productivity is reduced by...
Habitat loss is the biggest conservation challenge. Examples can include...
Rainforests cover 7% of the planet's landmass, but contain 66% of all species. This figure has dropped from 12% of the Earth's landmass, due to...
At current rates of consumption half of the remaining rainforest will be gone by 2022. We currently lose 50 million acres of rainforest per year. This drives 27,000 species (including birds) to extinction annually.
The cutting of North American forests began more than a century before clearing of rainforests. New Hampshire (and much of New England) was almost completely deforested by 1800. Bottomland forests of the Southeast (Ivory-Billed Woodpecker habitat) and the old-growth forests of the Northwest (Spotted Owl habitat) followed.
On a positive note, birds tend to find and inhabit new habitats fairly quickly. The forests of New England now support large populations of Pileated Woodpeckers and Broad-Winged Hawks. There have been many success stories of...
Restoration and careful management of natural habitats benefits game birds and songbirds - as well as many other types of wild plants and animals.
The Conservation Reserve Program (CRP) subsidizes the conversion of crop land into native grassland on certain farmland throughout the Midwest. These grasslands have benefitted pheasants and nesting ducks, as well as grassland species such as Eastern and Western Meadowlarks, Bobolinks, and Vesper Sparrows. Likewise, managing eastern forests to provide habitat for Ruffed Grouse and American Woodcock also benefits songbirds such as Field Sparrows and Golden-Winged Warblers.
Emerging and future conservation challenges include...
Humans have been altering landscapes and ecosystems for at least 50,000 years, although this has escalated dramatically over the past 10,000 years.
Since the last Ice Age, 10,000 years ago, humans have exterminated more than 9,000 species of birds. This is about half of the total number of bird species that survived the Ice Age.
About 90% of bird extinctions during historical times have involved island species. As humans explored the globe, these insulated, often flightless birds provided easy food supplies.
In addition to being used as food, the 1870's and 1880's saw the rise of bird plumes (or even whole birds) as fashion accessories. During this time, around 5 million birds were killed for this purpose alone.
The pet trade is a multi-million dollar industry (much of which is illegal) that exports between 2 and 5 million birds from their native tropical habitats to developed countries. In the 1980's, the US was importing around 1 million birds a year.
In 1992, Congress passed the Wild Bird Conservation Act - this was designed to eliminate the import of endangered species. By 1994, the annual import of cage birds had dropped to 80,000 per year.
Humans have the ability to stabilize declining bird populations, and even to increase them. Conservation initiatives and formal protections are a large part of this.
The US Congress passed the Endangered Species Act in 1973 (and amended it in '78 and '82). It classifies birds in trouble into two major groups:
The Ivory-Billed Woodpecker is one of the largest woodpeckers in the world, and inhabits the old-growth bottomland forests of the southeastern US. It was last seen for certain in 1944. Hunting and habitat loss were thought to have driven them extinct. However, a report and 4 seconds of video taken by a kayaker in Arkansas on Feb. 11, 2004 raised hopes that the bird is not lost. Since then, land has been protected to provide habitat for these birds.
Bird populations can be rebuilt from individual birds on the brink of extinction. Examples include Bald Eagles, Brown Pelicans, Sandhill Cranes, Whooping Cranes, Short-Tailed Albatrosses, and Wood Ducks.
Wood Ducks were almost wiped out by 1900, due to overhunting and habitat loss. The government closed the hunting season in 1918, and nest boxes were used to supplement natural nest sites. The Wood Ducks rebounded to the point were carefully controlled hunting was allowed in 14 states in 1941. Today, Wood Ducks number more than 2 million, are found throughout their original range, and are expanding into new territory.
DDT is a pesticide that affects all animals, including humans, creating symptoms such as growth deformities and neurological damage. Banning DDT, coupled with the use of captive breeding and reintroduction programs, has seen the recovery of populations of Bald Eagles, Ospreys, Peregrine Falcons, Aplomado Falcons, and other birds of prey.
Peregrine Falcons were almost wiped out due to DDT poisoning during the 1950's and 60's, especially in the eastern states. In an effort to bring them back, young falcons were raised in captivity and then released into the wild. This is called hacking. Between 1982 and 2005, 1249 young falcons were hacked. These new populations are now interbreeding with wild populations, increasing genetic variability.
The high costs of these programs are partially offset by the number of volunteers. In the effort to restore Peregrine Falcons, the 7000 falcons produced and hacked cost $17,500,000. In comparison, the least expensive US fighter jet, the F-16, cost $28,000,000 in 2001. So, one entire species of bird has been restored for less than the cost of a single fighter plane.
There are only two condor species left in the world today: the California Condor (N.Am.) and the Andean Condor (S.Am.). By 1988, the California Condor was extinct in the wild - mainly due to illegal shooting and lead poisoning (bullet fragments in deer carcasses). The last wild condor was captured in 1987 for use in a captive breeding program. Numbers of condors are on the rise again, but many young birds still die of lead poisoning soon after their release.
Birds have also benefitted by being provided with special nesting facilities...
Island birds and nesting seabirds are at high risk from hogs and goats (which eat the native vegetation) and cats and rats (which prey on the birds or their eggs). Various organizations have been working to remove invasive species. For example, Island Conservation (in California) evaluates islands at risk, then deploys teams of hunters, trappers, and Jack Russell terriers to remove the invaders. As a result of programs like these, many species of seabirds are now protected and their populations are rebounding.
Some colonial seabirds require social interaction. Colonies of Atlantic Puffins along the coast of Maine were wiped out by the 1800's due to hunting and egg harvesting. Releasing captive-raised puffins on these islands did not work, because puffins prefer not to settle down on an empty island. The puffins were finally enticed back to these islands by decoys and puffin voice recordings.
Conservation by Design
Conservation Biology sets priorities and integrates objectives with large-scale plans of habitat management. The goal is to protect and restore habitat in an effort to maintain healthy ecosystems with broad spectra of plants and animals.
The design of nature reserves must take into account bird movement and their seasonal needs. Corridors allow movement between reserves, which helps maintain genetic diversity. Designs and locations must be able to adapt to changes in climate - such as those due to global warming.
Populations of plants and animals tend to occur in patches - local populations. Local populations that interbreed are grouped into "metapopulations". If a local population disappears, other members of the metapopulation may move in and restore it. Managing populations must take two factors into account:
Small, fragmented populations lose genetic diversity (due to inbreeding or chance). This reduces survival and fertility, such that the population may not be able to recover.
Greater Prairie Chicken populations in Illinois dropped to the extent that conservation biologists imported birds from larger, more diverse western populations to maintain the genetic diversity.
Human activities such as cutting forests or converting grassland to cropland divide areas of habitat into smaller fragments. Small size and extensive edges of fragments leads to...
Forest fragmentation in N.Am. leads to higher rates of brood parasitism (laying eggs in someone else's nest to reduce your cost of reproducing and raising young) by Brown-Headed Cowbirds. Cowbird eggs tend to hatch earlier than the eggs of the host bird, and cowbird chicks will push other eggs and chicks out of the nest.
Parasitism is highest within 100-200m of the forest edge. The interior is relatively safe, so larger chunks of habitat are safer than smaller ones. Small fragments tend to be population sinks - places where local populations die out quickly.
Minimum critical size studies in the Amazon rainforest showed the following...
Natural disturbances, such as floods and fires, are a key part to keeping habitats vital. Healthy ecosystems include a variety of habitats, in different stages of recovery. Without this, there would be less habitat diversity, supporting less bird diversity.
Before the colonization of N.Am., one-half of the continental US burned every 1-12 years due to fires started accidentally by lightning or deliberately by Native Americans. Many habitats require regular burning in order to maintain themselves. This is especially true of grasslands - fire favors the growth of grasses, while discouraging the woody plants that would naturally take over due to succession. Young grasslands provide thick groundcover for nesting and a greater diversity of insect prey.
Florida Scrub Jays live only in the scrub habitats of central Florida. These habitats are renewed by regular fires (ever 8-15 years). When fires were suppressed by humans, the Scrub Jay populations declined due to competition from Blue Jays and predation by hawks and snakes. When the habitats were burned, Scrub Jay populations rebounded for a while, then began to decline - in anticipation of the next burn.
Regular (in many cases, seasonal) flooding...
Floodplain habitats are threatened by dams, channels, levees and other human attempts to control/minimize flooding.
Grasslands were originally grazed on by bison, antelope, and elk. More recently, they are grazed by domestic livestock. Overgrazing creates deserts, but moderate grazing and the rotation of livestock can help maintain healthy grassland. Birds such as Horned Larks and Montezuma Quail benefit.
In the US, commercial harvesting of trees for lumber causes more disturbance of habitat than natural processes do. As an area is cut, it then begins a series of successional stages in the process of recovery. Each stage accommodates a different set of species with specific habitat preferences. As the area matures, the species present change.
Spotted Owls rely on old growth forests of the Pacific Northwest. As these areas have been logged, the Spotted Owl habitat has declined. Fragmentation allows more competition from larger Barred Owls, and more predation by Great Horned Owls. Programs to protect habitat for Spotted Owls have been put in place.
To focus their resources on areas of greatest need, conservation biologists have identified "hot spots" - places in the world that are under threat and have the highest amounts of biodiversity. There are three main factors that define a "hot spot"...
Identified hot spots include...
More recently, the Important Bird Areas (IBA) program was established to protect a world-wide network of sites that stabilize bird populations and their essential ecosystems. The IBA network includes federal wildlife refuges and other protected public lands, as well as private and local community lands. So far, about 3,000 sites have been identified in the Western Hemisphere - with plans to grow to about 8,000 sites. (NH currently has 15 IBAs - they can be found here.)
Community support is vital to the success of any conservation movement. Thus, programs must take into account economic and social variables, as well as biological ones.
Local pride is often the key to public support. An endangered parrot, the Jacquot, was saved when conservation programs rallied the people of the island of St. Lucia. The Jacquot is now the island's national bird and its population has nearly doubled.
The Conservation Movement
The excesses of the 1700's and 1800's led to the beginnings of the conservation movement in the late 1800's. The American Ornithologists Union was founded in 1883, followed by state Audubon Societies and federal agencies such as the U.S. Bureau of Biological Survey.
The movement was supported by the writings of famous authors of the time, such as Ralph Waldo Emerson, Walt Whitman, John Burroughs, and John Muir.
1887 - Fannie Hardy and Florence Merriam founded the first Audubon Society at Smith College in Massachusetts. The goal was to get people on campus to stop wearing bird feathers.
1896 - Harriet Hemenway founded the Massachusetts Audubon Society. The goal was to discourage ornamental use of wild bird feathers and to protect birds.
1934 - Rosalie Edge purchased 1400 acres on Hawk Mountain in PA, and hired a warden (Maurice Broun) to protect the hawks passing through this key part of their migration route. The goal was to protect hawks and gain public support by encouraging hawk watching. Hawk Mountain now maintains the world's longest and most detailed record of raptor migration. The millionth raptor was logged on October 8, 1992. This database was used to uncover the connection between DDT and raptor mortality rates. It was also used to track population recovery when DDT was outlawed.
Several environnmental crises launched the modern environmental movement and motivated Congress to pass key environmental laws.
President Nixon's administration (1969-1974) accomplished more significant environmental legislation than any before or since - with the possible exception of Theodore Roosevelt (1901-1909).
Various local and national nonprofit organizations grew to engage the public. Today, there are more than 1,000 independent bird clubs, bird observatories, coalitions, and Audubon chapters in North America. Birdlife International is a coalition of national bird conservation organizations worldwide.
In 1986, the US, Canada, and Mexico developed the North American Waterfowl Management Plan (NAWMP). The goal was to protect millions of acres of wetlands and meet population goals for 32 species of ducks, geese, and swans.
In the 1990's, two more organizations arose...
Citizen science is research done by people from every level of society in collaboration with scientists. The oldest example of citizen science in the world is the Christmas Bird Count, which was started by Frank Chapman in 1900, in which volunteers from around the US and Canada report on how many birds/species they observe over the Christmas holidays.
A "birder" is defined as someone who "closely observed or tried to identify birds around the home and/or took a trip a mile or more from home for the primary purpose of observing birds." There are an estimated 46 million birders (age 16 and up) in the US. On average, they are well educated, earn above-average incomes, and belong to several conservation organizations. They range from beginners who can identify only a few species to experts who keep life lists of species seen.
Birding provides economic support for communities and governments, as well. In 2001, US birders and wildlife watchers spent an estimated $24 billion on binoculars, bird food, camp equipment and other items; and another $7 billion on travel. This generated about $85 billion in economic output and $13 billion in state and federal income taxes.
The American Birding Association has developed a code of birding ethics to protect the birds being observed and to help promote responsible behavior on the part of the birders. The code can be found here.