Bird species declining


This video is an introduction to BirdLife International’s State of the World’s Birds report.

From BirdLife:

Birds indicate biodiversity crisis – and the way forward

22-09-2008

Common birds are in decline across the world, providing evidence of a rapid deterioration in the global environment that is affecting all life on earth – including human life. All the world’s governments have committed themselves to slowing or halting the loss of biodiversity by 2010. But reluctance to commit what are often trivial sums in terms of national budgets means that this target is almost certain to be missed.

These are some of the stark messages from State of the Worlds Birds, a new publication and website (birdlife.org/sowb) launched today at BirdLife International’s World Conference in Buenos Aires.

“Birds provide an accurate and easy to read environmental barometer, allowing us to see clearly the pressures our current way of life are putting on the world’s biodiversity”, said Dr Mike Rands – BirdLife’s CEO.

The report highlights worldwide losses among widespread and once-familiar birds. A staggering 45% of common European birds are declining [1]: the familiar European Turtle-dove Streptopelia turtur, for example, has lost 62% of its population in the last 25 years. On the other side of the globe, resident Australian wading birds have seen population losses of 81% in just quarter of a century [2].

Twenty North American common birds have more than halved in number in the last four decades [3]. Northern Bobwhite Colinus virginianus fell most dramatically, by 82%. In Latin America, the Yellow Cardinal Gubernatrix cristata – once common in Argentina – is now classified as globally Endangered [4].

See also here.

Northern cardinal: here.

1 thought on “Bird species declining

  1. Predator removal may not increase nesting success

    You may have experienced the disappointment that accompanies a nest failure, whether due to bad weather, nest parasitism, or predators. When a predator raids a nest that you monitor, it is common to wonder if there is anything that you can do to eliminate this threat. But before you blame that snake or raccoon, please consider that every animal has a role to play in its environment and birds have always experienced such losses to some degree. Also, eliminating specific nest predators from an area may have little impact on the overall survival of bird populations.

    Scientists recently observed nests of Northern Bobwhite with cameras to learn if predator removal would increase bobwhite nesting success. (This species nests on the ground and typically has low nesting success.) They found that the removal of common predators, like raccoons, opossums, and armadillos, did make these species less abundant within the area, but it did not increase the bobwhites’ nesting success. When these predators were removed, other less common predators, such as snakes, rodents, and fire ants, preyed on nests instead. This effect is known as compensatory mortality, and it applies to fledglings and adult birds, too. Although it’s upsetting to witness the consequences of a predator visiting a nest, keep in mind that it’s impossible to completely eradicate all predators and removing one primary predator from an area can actually make matters worse by allowing other nest predators, which were formerly kept in check by the primary predator, to thrive. Take heart, though, because a good number of young birds do fledge–many of them, no doubt, thanks to the favorable habitat and predator guards provided by many nest monitors. For tips on safeguarding nests, read our article on Dealing with Predators and our Code of Conduct.

    Reference: Ellis-Felege, S. N., M. J. Conroy, W. E. Palmer, and J. P. Carroll. 2012. Predator reduction results in compensatory shifts in losses of avian ground nests. Journal of Applied Ecology 49(3):661-669.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.