Friday, June 27, 2008

Bird Population Extremes

It seems as though extremes in life are not good, and I think bird population extremes are no different.

 The most numerous bird in the world, as reported in the wonderful BBC documentary Planet Earth, is thought to be the Red-billed Quelea. It is found in Africa and its population is estimated to be a staggering 1.5 billion! People have reported seeing flocks that bolt out the sun and take 5-6 hours to pass. What an incredible sight that must be!

With regard to the rarest bird in the world (i.e. with a population in the wild) there are a number of species that are listed as Critically Endangered with populations below 100 individuals. By continent these species are:
The North American entry is perhaps a bit controversial, and the search is ongoing for this bird. It has apparently been seen in Arkansas by a few reputable birders, but no unequivocally conclusive photos have been taken. So perhaps time will tell on that one.
The extreme of having 1.5 billion individuals has created an agricultural pest for Kenyan cereal grain farmers. The extreme of having such low numbers creates the sad experience of extinction. Neither is much of a good prospect and thankfully most of the approximately 10,000 bird species are somewhere in between these two poles of the spectrum.

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This book offers a guide to some of the rarest birds in existence, with maps that show where to find them. Focusing on fifty captivating stories of the very rare, it describes remarkable discoveries of species not seen for centuries and brought back from the brink of extinction, successes like the Seychelles Magpie-Robin and the California Condor.




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