Tundra to Tropics: Connecting Birds, Habitats, and People

•In North America, more than half of the coastal temperate rainforests, once extending from California to Alaska, have been destroyed. Coastal temperate rainforests are one of the most ndangered forest types on the planet.

•The natural tropical forest cover in Latin America and the Caribbean continues to decrease at alarming rates. A total of 5.8 million hectares a year was lost during 1990-95, resulting in a 3% total loss for the period.

•Fifty-one percent of all migratory birds in North America spend the winter in Mexico. These birds face the loss of critical overwintering sites due to deforestation with a rate of forest loss estimated at 600,000 to 2.5 million acres per year.

•One third of North America’s songbirds migrate to the Boreal Forest to breed. In 2001,85,000 migratory bird nests were destroyed from logging in Canada’s Boreal Forests.

•From September to May, almost two-fifths of the song birds in Jamaica are migrants from North America. This rich birdlife is threatened by the country’s extremely high deforestation rate of 5.3% per year, which is one of the highest in the world.

•Nearly 20% of the dry land area on Earth was covered by tropical forests in the 19th century.  This figure dropped to less than 7% by the end of the 20th century.

•More than 50% of all wetlands in the contiguous United States have been drained or filled since the time of European settlement.

•Riparian areas in the western United States (only 1% of the landscape) support a higher diversity of breeding songbirds than any other habitat. These areas have been severely impacted by human activities, particularly livestock grazing.

•The midwestern states have been particularly hard on their marshes and swamps—Ohio, Illinois, Indiana, Iowa and Missouri have drained more than 85% of their original wetlands.

•There are 50 wetlands of international importance in North America covering 14.2 million hectares, of which 13 million hectares are in Canada.

•More than 50% of the original wetland area of Trinidad and Tobago has disappeared. The resources of the surviving wetlands are severely degraded providing poorer habitat quality for migrating birds.

•The North American Waterfowl Management Plan has protected, restored, or enhanced more than 15 million acres of marshes and forested wetlands in Canada, the United States, and Mexico between 1986 and 1996.

•Most remaining grasslands in the East and Midwest are fragments so small that Brown-headed Cowbirds and predators can readily parasitize or destroy nests of birds nesting there.

•Land management practices such as fire suppression, grazing, and water regulation have created a massive invasion of exotic grasses and shrubs on millions of acres of native grasslands and steppe in western North America.

•The once-abundant grasslands of the Great Plains and Upper Midwest now represent 5% or less of their original abundance. With this drastic reduction, grassland-dependent bird species have undergone widespread and significant populations declines.

•Local and large scale changes in shrublands throughout the Intermountain West have had a detrimental influence on distribution and abundance of breeding birds. Populations of shrubland and grassland birds have had the greatest rate of declines of any groups of birds and many species receive special conservation status in part or all of the region.

•Since 1830, the provinces of Canada and the United States have lost 20-86% of their shortgrass prairies, 31-99% of their mixed-grass prairies, and 83-99% of their tall grass prairies.

•Much of the grasslands in South America, such as the steppes of Argentina, have been degraded by overgrazing. Only one acre is protected for every 10 that is lost.

•Mangroves have been disappearing fast over the past 20 years, and as much as 65% of Mexico’s mangroves have already been lost. Coastal water quality has been declining through out the region, due to increasing discharges of untreated municipal waste.

•There are 30 to 70% fewer King Rails, Virginia Rails, Soras, Lesser Yellowlegs, and Black Terns today than there were only 30 years ago.

•Of 74 populations of shorebirds breeding in North America, only 12 have population trends that appear to be stable or increasing; the vast majority (84%) are unknown or declining.

•More than half of all original barrier island vegetation and coastal wetlands in the United States have been destroyed or altered, thereby depriving birds important resting and feeding sites during migration.

•Estimates of population trends for 166 colonial waterbirds in North America (includes Caribbean, Central America, Canada, U.S., and Mexico) indicate that 7% are showing a biologically significant decline and another 24% show apparent declines.

•Of the waterbirds, of greatest concern are species of island-nesting seabirds facing threats on land and at sea as well as rail species that exist only in small numbers in limited pockets of habitat.

•Exploration of oil, gas, and minerals and construction of pipelines and roads cause physical disturbances and habitat fragmentation to the species that live in the arctic.

•Invasive species push aside native vegetation and reduce diversity of plant cover.

•Mining and road development are the primary human factors contributing to habitat loss in the arctic. Fifteen percent of the habitat loss in the area occurs in the valley bottoms, which contain the most productive habitats.

•There are no protected areas in the Yukon.

•Tundra habitats are fragile and take a long time to (or never) recover if they are damaged.

•Homes in neighborhoods with large trees for birds cost less to cool and heat and are worth more than similar homes in neighborhoods without trees.

•Many tropical birds, and birds that migrate to the tropics during the winter, are important for the pollination of many valuable species of flowers and trees.

•By eating thousands of leaf-damaging insects each day, birds in the Ozarks allow commercially valuable white oak trees to grow faster than they would if birds were not in those forests.

•Birds save the timber industry tens of millions of dollars in timber damage each year by consuming wood boring insects.

•The Blue Jay is one of the “Johnny Appleseeds” of the bird world, playing an important role in dispersal of acorns, and hence oak trees, in the Midwest.

•Raptors, such as Swainson’s Hawk, Red-tailed Hawk, and Great-horned Owl, provide a natural control for rodents that destroy crops and infest grain supplies.

For additional information:

USGS Status and Trends of the Nation’s Biological Resources series
USFWS’s Status and Trends of Wetlands in the Conterminous United States 1998-2004
United Nations Environment Programme’s Global Environment Outlook 2000

Courtesy of International Migratory Bird Day