September 2009
A young Snowy Owl (Bubo scandiacus) on the tundra at Barrow, Alaska. Warming temperatures may be affecting the owl’s food resources. Photo: Floyd Davidson.
There is no fauna more ubiquitous in our world, or more treasured by humans around the globe than birds. Birds are:
- a prominent component of our natural world,
- an integral part of our culture,
- a measurable factor in our economies, and indeed,
- a vital part of our lives on earth.
We hear them when we wake and as we take every breath of fresh air in the out-of-doors. Birds are a priceless part of our heritage. They are beautiful, they are economically important, and they reflect the health of our environment. Birds are truly ever-present in our lives, but are they a constant in the world?
In an unprecedented partnership, government wildlife agencies and conservation organizations have come together to produce the first comprehensive analysis for the United States of America—the State of the Birds Report.1 The analysis in this report provides some sobering facts and statistics, which should be a wake-up call to us to motivate conservation action and to prompt us to attend to the challenges and problems that exist in our environment today. While there is almost an unending array of challenges that we confront, the report clearly presents reason for hope. Analyses show that when we humans truly care, we can amass the actions necessary to conserve these natural treasures, and indeed, the world within which the birds and we live.
Birds have been used as environmental health barometers at a local level ever since canaries were used to indicate the safety of air in coal mines; only in recent years, however, have we used monitoring data and analytical tools to use wild bird populations as environmental health barometers on a large spatial level.
Overview of birds in America
Birds are bellwethers of our natural and cultural health as a nation—they are indicators of the environment’s integrity, on which we humans depend for clean air and water, fertile soils, and other natural resources.
Red Knot, Calidris canutus, populations crashed when overharvesting of horseshoe crabs led to the decline of the birds’s major food — the crabs’ eggs. Photo: Jan van de Kam.
- Birds are found in virtually every ecosystem on earth.
- Birds depend upon other biota and natural resources for their existence.
- They are reasonably easy to observe and count.
- Both amateurs and professional ornithologists can monitor bird populations effectively.
- Bird populations have been monitored for more than a century (long-term databases exist to mine).
- Many bird species migrate, exploiting different habitats during a lifecycle.
Successful conservation begins with information about the species’ status through well-designed monitoring programs. The State of the Birds Report presents a new synthesis of major bird-monitoring databases, including data from thousands of citizen scientists and professional biologists. Data from three continent-wide monitoring programs (U.S. Fish and Wildlife Service’s Breeding Waterfowl Populations,2 U.S. Geological Survey’s Breeding Bird Survey,3 and Audubon’s Christmas Bird Count4) are used to create bird population indicators for major U.S. habitats, which reflects the health of these habitats, and the environmental services they provide. The U.S. is home to a tremendous diversity of native birds:
- There are more than 800 species, overall.
- Among these species, 67 are federal listed as endangered or threatened.
- An additional 184 are species of conservation concern because of their small distribution, persistent threats to them or their habitat, or their declining populations.
Overview of birds by ecosystem
The data in the report reflects the influence of human activities and global change on our nation’s birds.
- Every U.S. habitat harbors birds in need of conservation.
- Hawaiian birds and ocean birds appear most at risk—with populations in danger of collapse if immediate conservation measures are not implemented.
- Bird populations in grassland and aridland habitats show the most precipitous declines over the past 40 years.
In contrast, many wetland species, wintering coastal birds, and waterfowl populations are experiencing increases over the past 40 years—perhaps because of a strong focus by communities to conserve and manage wetlands and to improve water quality.
Hawaiian birds in crisis
The Nihoa Millerbird, Acrocephalus familiaris kingi, is limited to the tiny island of Nihoa in the Northwestern Hawaiian Islands. Only several hundred remain, making them seriously endangered. Photo: Craig Rowland, USFWS
Threatened by habitat destruction, invasive species, and disease, nearly all native Hawaiian bird species are in danger of extinction if conservation measures are not implemented immediately. Since humans colonized the islands in 300 AD, at least 71 Hawaiian bird species have become extinct, and 10 other birds have not been seen in as long as 40 years. Aggressive conservation action is needed to save the biodiversity that remains and avert this global tragedy. This means protecting forests, eliminating exotic and invasive predators, and implementing other intensive management actions.
Ocean birds—out of sight, but not out of concern
Some of our most imperiled species spend much of their lives on the oceans and only come to land during the brief breeding periods. Almost 40% of the U.S. bird species restricted to ocean habitats are declining, and almost half are of conservation concern, which indicates deteriorating ocean conditions. Resource use (commercial fishing), pollution from pesticides, heavy metals, plastics, oil, and climate change (rising sea temperatures and changing chemistry) are placing significant stressors on ocean birds.
The Short-tailed Albatross, Phoebastria albatrus, is a large rare seabird from the North Pacific. It is listed as endangered on a number of U.S. state lists, including Washington State. Photo: James Lloyd.
Birds, such as albatrosses that have low reproductive capacity are particularly vulnerable; and they stand too close to the precipice of being lost forever as mortality outpaces reproduction. Management policies, international cooperation, and sustainable fishing regulations are essential to ensure the health of our ocean birds. To add more concern, too little data exist to determine the population trends for 12% of ocean birds.
Coasts—where land meets sea, coastal protection offers hope
This important interface between habitats is incredibly rich with a diversity of birds, and the coast is a critical habitat for many species. Of the 173 bird species that use coastal habitats at any time of the year, 53 are species of conservation concern, and 14 are federally listed as endangered or threatened.
A Brown Pelican (Pelecanus occidentalis), listed as endangered, flying over the harbor at Fulton, Texas. Photo: Alan D. Wilson, www.naturespicsonline.com
- Generalist birds, such as gulls, have been extremely successful in developed areas through adaptation; nevertheless, specialized species, such as shorebirds, have declined.
- Half of all migrating shorebirds have declined, which indicates stress in coastal habitats besieged by development, disturbance, and dwindling food supplies.
- While efforts are needed to conserve shorebirds, species such as egrets, herons, and fish-eating raptors (ospreys and bald eagles) have experienced dramatic increases—possibly due to a reduction in the use of DDT and other chemicals, as well as the regulations aimed at improving water quality.
The competition for this habitat by humans makes it vulnerable. Balancing the development of humans with the needs of wildlife has never been more important. Incentives and habitat protections are needed to change the trend lines for some of these long-distance migrants.
Aridlands—birds in trouble surprise science team
Aridlands are areas where there is low annual precipitation that varies from one year to the next. Aridlands in the U.S. include deserts such as the Sonoran and the Mojave and major shrub-scrub ecoregions such as the Colorado Plateau.
Most migratory aridland species winter in Mexico and Central America, such as this endangered Golden-cheeked Warbler, Dendroica chrysoparia. Photo: Steve Maslowski, USFWS.
The aridland birds’ indicator shows a 30% decline over the past 40 years. Sixty percent of all aridland species and 76% of aridland obligate species have declined. Unplanned urban sprawl is the greatest threat to aridland birds. A regional system of protected areas can enhance quality of life for people and enable birds to survive. Competition for scarce water, and a changing climate, makes the future of these habitats uncertain, and the wildlife therein at risk.
Given that 50% of aridland birds are permanent residents of the U.S. borderlands, effective conservation requires a close collaboration with the Mexican government and private conservation organizations. Most migratory species winter in Mexico and Central America. New and existing international partnerships must be supported to ensure the survival of aridland birds—with a particular focus on sagebrush ecosystems.
Grasslands—America’s Heartland is home to our nation’s fastest declining birds
The Lesser Prairie-Chicken, Tympanuchus pallidicinctus, a popular game bird, is losing its habitat because of loss and fragmentation of grasslands. Photo: Wikimedia Commons.
Grassland birds are among the fastest and most consistently declining birds in North America. Forty-eight percent are of conservation concern, and 55% are showing significant declines. Agriculture, energy exploration, and climate change are having huge impacts in this landscape. Farm conservation programs provide millions of acres of protected grasslands that are essential for the birds in a landscape where little native prairie remains. Only about 2% of the tallgrass prairie that existed in the early 1800s remains. Although birds may settle in pastures and haylands, frequent haying, burning, and overgrazing can create “ecological traps,” where birds try to nest but fail to raise their young. The future of these species is depends on U.S. Department of Agriculture programs to provide grassland habitats, as well as state and local conservation efforts.
Forests—A Mixed Bag of Results
The Wood Thrush, Hylocichla mustelina, requires large blocks of intact forests. Photo: Steve Maslowski, USFWS.
North America has a tremendous diversity of forests harboring more than 300 breeding bird species. Some forest birds are doing well, but roughly one-third of all forest-breeding species have declined. Based on 96 species that represent eastern, western, boreal, and subtropical forests, the forest birds indicator dropped by roughly 10% from 1968-1980; it has increased slightly more recently. In eastern forests, the indicators dropped by nearly 24%. Sustainable forestry practices improve the long-term health of forests, and therefore, its birds; so, these systems should be encouraged nationwide. Economically viable practices on private lands and incentives for private landowners can provide a mosaic of forest ages and structure to benefit diverse birds.
Arctic—what we know concerns us
Endangered Spectacled Eider, Somateria fischeri, male (front) and female (rear) at the Alaska SeaLife Center, Seward, Alaska. Photo: Laura Whitehouse, USFWS.
Because the arctic is vast and remote, data are lacking for many species. Some birds, such as geese and most gulls, are faring well, but many shorebirds and landbirds are showing worrisome declines.5 The arctic ecosystem reveals dramatic signs of change. Some bird species are taking advantage of, and adapting to, these changing habitats; however, some species are suffering declines. Arctic-nesting geese are increasing dramatically, but 38% of species that breed in arctic and alpine regions are of conservation concern. The future of arctic habitats and birds depends on our ability to curb global climate change and to explore energy resources with minimal impact to wildlife.
Marsh birds—what we don’t know gives us pause
The three southernmost subspecies of the Sandhill Crane, Grus canadensis, are very rare. Photo: Oksana Hlodan.
Wetland bird species, such as ducks and rails, depend on the vegetation in freshwater marshes to raise their young. Because many marsh birds are notoriously difficult to detect, the species indicator may not accurately reflect the status of these populations. For 31 species with adequate data, the marsh bird indicator shows a steady decline until about 1990, followed by wide fluctuations over the last two decades, which perhaps reflects precipitation patterns. Marsh birds respond quickly to management and restoration efforts, and even small marshes can support large numbers of birds.
Urban habitats—for birds and people
More than 100 species of native birds inhabit urban or suburban environments. The indicator for these birds shows an increase of 20% over the past 40 years, driven primarily by a small number of very successful species such as gulls and doves. Creating green space for birds in cities can help adaptable urban birds, as well as migrants that stop over during their long journeys. The abundance of birds in these environments gives millions of Americans an opportunity to enjoy wildlife in their “backyard,” an important, yet often overlooked benefit to our well-being and economy.
Looking to the future
Each year, thousands of citizen-science participants from across the United States contribute data to important surveys of birds. However, little is known about the population trends of birds in some habitats, such as the arctic, hampering our ability to help them. Greater monitoring efforts are needed to ensure that we can identify where birds and habitats need help—while we still have time to make a difference.
In addition to improving monitoring programs in the future, the team of scientists involved in the State of the Birds Report intends to generate annual reports looking at particular issues or geographic areas using birds as indicators of environmental health. The team plans to reissue a new comprehensive report similar to that of 2009 on a periodic basis—perhaps every four to five years. These reports will help prioritize conservation actions and better utilize our limited resources for conservation.
What you can do
Are you captivated by the ideas in this article? Would you like to contribute to bird conservation? The 2009 report used data from current citizen science projects, such as The North American Breeding Bird Survey and National Audubon Society’s Christmas Bird Count; the latter is the oldest citizen science project, which has been conducted since 1900. You may want to participate in on-going citizen science projects conducted by these groups and so contribute to future reports.
Another resource is the eBird project—a real-time, online checklist program, launched in 2002, by the Cornell Lab of Ornithology and National Audubon Society. Each year, recreational and professional bird watchers contribute their observations to eBird. For example, in 2006, eBird participants reported more than 4.3 million bird observations across North America.6 You too can contribute to the welfare of birds as an official eBirder or by participating in other bird survey programs.
© 2009, American Institute of Biological Sciences. Educators have permission to reprint articles for classroom use; other users, please contact editor@actionbioscience.org for reprint permission. See reprint policy.
