Tag: State of the Birds 2010

State of the Birds 2010: It’s Not All Doom and Gloom!

Written by | March 19th, 2010

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Dave Mehlman, the director of The Nature Conservancy’s migratory bird program, is blogging all week about the new “State of the Birds 2010″ report, of which he is a co-author. Read all his posts on the report — then go to my.nature.org to learn more about the report and the Conservancy’s work to protect birds.

There is an almost irresistible tendency when discussing the effects of climate change on birds (as illustrated by the State of the Birds report) to portray the results as inevitably bad. Indeed, our analyses of bird species vulnerability to climate change does suggest that many species show elevated vulnerability to climate change.

However, the great difference between birds from different habitat types in their vulnerability suggests that there are indeed some species who will do just fine in the face of climate change, including some who may well prosper. In addition, some conservation efforts are already underway to help birds adapt to a changing climate, providing yet another element of good news.

The relatively low proportion of bird species occurring in forests suggests that, due to their high reproductive potential and large ranges, many forest birds will fare better in the future (though we may see some species that become rarer in the United States but more common in Canada).

There are numerous examples of birds that are now of relatively restricted range in the United States but are currently expanding dramatically, such as Cactus Wren, Cave Swallow and White-winged Dove. Similarly, species now rare in United States but found commonly in Mexico may move northward and become more common in our country, including Northern Beardless-Tyrannulet, Bronzed Cowbird and Crested Caracara.

Perhaps the best news is that conservation efforts are already underway that will help birds in the face of climate change. For instance:

  • Planners and refuge designers across the country are aware of the changes that are coming and can incorporate this knowledge into their work — for example, by developing altitudinal or elevational corridors connecting protected areas.
  • Recent efforts at translocating individuals from one place to another, such as those implemented for the Bermuda Petrel, offer great hope for ensuring the survival of rare species, albeit in a relatively expensive manner.
  • The Nature Conservancy has been actively partnering with the U.S. Fish and Wildlife Service at the Alligator River National Wildlife Refuge, North Carolina, in an innovative project to protect coastal marshes by plugging ditches to limit saltwater intrusion, planting salt tolerant species, and building oyster reefs for shoreline protection.

Climate change presents a strong challenge to most of our nation’s birds, exacerbating the largely negative trends we showed in the 2009 State of the Birds report. However, not all species will be affected equally –and some perhaps many species will benefit in some form. There are promising strategies for helping species adapt to a changing climate and these efforts must be expanded, coupled with a rigorous monitoring scheme to determine their effectiveness. Although the picture appears dark for birds overall regarding climate change, there are some lights in the darkness which may help guide our way.

(Image: Cactus wren. Image credit: SearchNetMedia/Flickr through a Creative Commons license.)

Opinions expressed here and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy. For more information about our editorial policy and legal terms of use, see our About This Blog page.

State of the Birds 2010: Aridlands, Grasslands, and Forests

Written by | March 18th, 2010

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Dave Mehlman, the director of The Nature Conservancy’s migratory bird program, is blogging all week about the new “State of the Birds 2010″ report, of which he is a co-author. Read all his posts on the report — then go to my.nature.org to learn more about the report and the Conservancy’s work to protect birds.

The 2010 State of the Birds report focuses on birds and climate change — and found that birds of the three primary terrestrial habitat types (aridlands, grasslands, forests) showed relatively the least vulnerability to global warming.

However, each of these habitat types contains species that are dramatically more vulnerable to climate change. Even more notable, most of these species are not currently considered of conservation concern, suggesting that future attention will be warranted if action is not taken now.

Aridlands and grasslands share similar predicted effects of climate change: They will become warmer and drier. In aridlands, we also expect the already variable precipitation regime to become yet more variable, with longer and harder droughts and infrequent spells of heavy precipitation.

Aridlands are also at risk of increased invasion by non-native species of plants which could have major negative effects on our native avifauna. Examples of vulnerable aridlands species are found across the country, including Greater and Gunnison Sage-Grouse of the Colorado Plateau and Great Basin, Bendire’s and Crissal Thrasher of the Chihuahuan Desert, Black-capped Vireo of the Edwards Plateau, and Wrentit of the coastal California chaparral.

Grasslands are at great risk of invasion by woody species — both native and introduced — that can irretrievably alter these systems and affect the birds that rely on them. Although some grassland species, such as Loggerhead Shrike and Northern Bobwhite, are tolerant of some degree of woody plant cover, many other species of grassland birds, such as Chestnut-collared Longspur, will disappear with even a slight increase in woody shrubs. Other grasslands species particularly vulnerable to climate change include resident birds such as the Sharp-tailed Grouse and Greater and Lesser Prairie-Chicken and long distance migrants such as Wilson’s Phalarope, Dickcissel, and Bobolink.

Although birds of forests show relatively the least vulnerability to climate change of all habitats we analyzed, we nevertheless expect change to occur. Northward shifts in tree species’ ranges, increases in the frequency of insect outbreaks, longer and more severe fire seasons, and generally drier conditions will all result in changed bird species distributions.

Some of the most vulnerable forest species include those restricted to isolated, small habitat types in either the breeding or wintering season, such as Kirtland’s Warbler or Bicknell’s Thrush.  Of most concern, however, are a group of species known as “aerial insectivores”, such as Black Swift, Whip-poor-will, and Chuck-will’s-widow, which, in addition to the factors listed above, are at risk from declines in their medium and large-bodied insect prey.

(Image: Bobolink, Chester County, Pennsylvania. Image credit: kellycolganazar/Flickr through a Creative Commons license.)

Opinions expressed here and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy. For more information about our editorial policy and legal terms of use, see our About This Blog page.

State of the Birds 2010: Arctic/Alpine and Wetlands

Written by | March 17th, 2010

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Dave Mehlman, the director of The Nature Conservancy’s migratory bird program, is blogging all week about the new “State of the Birds 2010″ report, of which he is a co-author. Read all his posts on the report — then go to my.nature.org to learn more about the report and the Conservancy’s work to protect birds.

The 2010 State of the Birds report focuses on birds and climate change, and shows that birds of Arctic and Alpine habitats are some of the most vulnerable in the country to climate change.

Documented temperature increases in the Arctic are already greater than in other regions — and we expect equally dramatic changes in the distribution of surface-water vegetation and food resources. Given that Alpine habitats are inherently insular in nature, we expect many of the effects of climate change on islands to be duplicated in Alpine areas, including the total loss of these habitats at lower elevations and latitudes.

Species affected by these changes including many of our long-distance migrating shorebirds and waterfowl, plus species restricted to the highest elevation habitats of the interior mountains. These include Surfbird and Black Turnstone, which breed on the Arctic tundra, and Brown-capped Rosy-Finch of the Rocky Mountains.

Melting permafrost may release contaminants into the environment, adding new threats to those faced by Spectacled Eider, Yellow-billed Loon, and Sabine’s Gull.  Changes in the abundance and distribution of small mammals could lead to decreases in Snowy Owls and jaegers or an increase in their reliance on birds and other prey.

Although wetlands birds in general show relatively lower vulnerability to climate change compared to other habitat types, it is clear that even small changes in precipitation and temperature can degrade or eliminate wetlands over broad areas. This is especially true of the shallow wetlands of the Prairie Potholes, Americas “duck factory.”  Examples of species particularly vulnerable include Western and Clark’s Grebes, Northern Pintail, and Black and Clapper Rails.

(Image: Snowy owl against snow in Alberta, Canada. Image credit: BugMan50/Flickr through a Creative Commons license.)

Opinions expressed here and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy. For more information about our editorial policy and legal terms of use, see our About This Blog page.

State of the Birds 2010: Oceans, Coasts and Islands

Written by | March 16th, 2010

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Dave Mehlman, the director of The Nature Conservancy’s migratory bird program, is blogging all week about the new “State of the Birds 2010″ report, of which he is a co-author. Read all his posts on the report — then go to my.nature.org to learn more about the report and the Conservancy’s work to protect birds.

The 2010 State of the Birds report focuses on birds and climate change. Of all the habitat types examined for the vulnerability of their birds to climate change, oceans stand out: all of the 67 oceanic birds we considered had medium or high vulnerability to climate change. Two other habitat types also defined by their connection to marine environments showed high vulnerability to climate change: coasts and islands (including Pacific and Caribbean islands).

Birds of the nation’s oceans — which include species such as Laysan and Black-footed Albatrosses, Black-capped Petrel, shearwaters, puffins, Common and Thick-billed Murres, and auklets — have numerous traits which make them slow or unable to adapt to climate change:

  • Most of these species have what scientists call “low reproductive potential” (they do not breed until several years old, produce one egg every year or every two years, and/or have very high mortality of young birds).
  • Many nest in highly concentrated colonies on islands and forage long distances for food, which is in itself very vulnerability to climate change.

This combination of factors makes all ocean birds vulnerable — and argues for increased conservation attention for this group.

Birds of coastal habitats are almost equally at risk, primarily from rising sea level, but also from increased flooding and erosion. These species occur across the country in an array of habitats, including Black and American Oystercatchers, whose low-lying beach nesting habitat may disappear; Seaside and Saltmarsh Sparrows, which are exclusively dependent on low lying salt marshes that may be the first to go; and seabirds such as Ivory Gull, Aleutian Tern, and Kittlitz’s Murrelet, which depend on coastal marine food webs that are at risk of disruption.

Island birds, particularly those from Hawaii, showed marked vulnerability to climate change, paralleling a finding from the 2009 report.  A variety of factors combine to produce this effect, including:

  • Rising sea levels and temperatures, which reduce both coastal and terrestrial habitats;
  • The small size of islands generally; changes in precipitation amounts and patterns; and
  • Potential increases in frequency of natural disasters.

High elevation forest birds, such as the Puaiohi and ‘Akiapola’au of Hawaii, Elfin-woods Warbler of Puerto Rico, and Rota Bridled White-eye of the Northern Marianas face numerous challenges due to constriction or outright loss of their habitat and (in Hawaii) loss of previously malaria-free refuges.  Coastal nesting island birds, as in the rest of the country, are at great risk; examples include the Laysan Finch of Hawaii, American Flamingo in the Caribbean, and Micronesian Megapode in the Northern Marianas.

Opinions expressed here and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy. For more information about our editorial policy and legal terms of use, see our About This Blog page.

(Image: American Flamingoes. Credit: cliff1066™/Flickr through a Creative Commons license.)

State of the Birds 2010: Climate Change

Written by | March 15th, 2010

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Dave Mehlman, the director of The Nature Conservancy’s migratory bird program, is blogging all week about the new “State of the Birds 2010″ report, of which he is a co-author. Read all his posts on the report — then go to my.nature.org to learn more about the report and the Conservancy’s work to protect birds.

The 2010 State of the Birds report, released last week by U.S. Secretary of the Interior Ken Salazar, is a follow-up to last year’s groundbreaking report by the same name. This year’s report focuses on climate change, perhaps one of the most critical issues to our nation’s birds.

The report, again a product of the North American Bird Conservation Initiative and an array of federal agencies and private conservation groups, starts with the assumption that birds are sensitive indicators of the effects of climate change on our environment. It looks at how birds are doing and might fare in a changing world.

The team developing the report, of which I was a member, assessed each species in the United States for its vulnerability to climate change, based on its biological sensitivity to climate and the exposure of its habitat to short-term climate change.

Using this assessment, we were able to analyze all the major habitat types that we used in the 2009 report to determine the relative vulnerability of habitats to climate change. We were also able to explore how various subgroups and species of birds within habitat types might vary in their susceptibility to climate change.

We found dramatic differences between habitat types in their birds’ vulnerability to climate change:

  • By far the most vulnerable are oceanic birds and those found in Hawaii.
  • Birds of coastal, arctic and alpine, grasslands, and on Caribbean and other Pacific Islands showed intermediate vulnerability.
  • Lower levels of relative vulnerability were shown by birds of aridlands, wetlands and forests.

Across all habitat types, birds species already considered of conservation concern (such as those listed under the Endangered Species Act, on the U.S. Fish and Wildlife Service’s Birds of Conservation Concern list, or on the American Bird Conservancy/Audubon Watchlist) showed higher vulnerability than those not already considered of concern.

This finding clearly implies that climate change will exacerbate the currently precarious status of these species. However, this same analysis also clearly points out certain species which are likely to become of concern in the future, even though they currently are not.

I’ll outline some of those species in my follow-up posts this week.

(Image: Red-footed booby at Palmyra Atoll. Image credit: Jonathan Reed/TNC.)

Opinions expressed here and in any corresponding comments are the personal opinions of the original authors and do not necessarily reflect the views of The Nature Conservancy. For more information about our editorial policy and legal terms of use, see our About This Blog page.

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