Recently scientists from the Zoological Society of London and Yale University assessed the world's 9,993 bird species according to their evolutionary distinctiveness and global extinction risk. At number three on the list is the Critically Endangered California condor (Gymnogyps caliÂfornianus) - weighing as much as 25 pounds, standing over four foot tall, with a wingspan of almost 10 feet, it is the largest land bird in North America.
Recently scientists from the Zoological Society of London and Yale University assessed the world's 9,993 bird species according to their evolutionary distinctiveness and global extinction risk.
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At number three on the list is the Critically Endangered California condor (Gymnogyps caliÂfornianus) - weighing as much as 25 pounds, standing over four foot tall, with a wingspan of almost 10 feet, it is the largest land bird in North America.
Riding on wind currents to heights of 15,000 feet and travelling up to 150 miles a day in search of food, these majestic birds once flew by the thousands above the California land mass and far beyond.
The condor flies again
Sadly, condor numbers dropped so drastically that in 1987 the last living wild condor was taken into captivity and put into a breeding program to save the species.
Now only 238 free-ranging condors - all descendants of captive breeding in the Condor Recovery Program initiated in the early 1980s -inhabit the skies above California, Arizona, Utah, and Baja California. A further 195 are in zoos, captive breeding programs, or being held for release or medical treatment.
This is a far cry from sustainable population numbers but it is also far better than the numbers in April 1987 through 1991 when the North American skies were empty of condors.
Although one of the very first species listed under the Endangered Species Protection Act of 1966, condor populations plummeted for decades. How did things go so wrong?
Humans took a heavy toll: habitat loss and destruction, hunting, egg and specimen collecting, the capturing of live birds, ingestion of DDE (a breakdown form of the pesticide DDT), accidental ingestion of lead from spent ammunition and other assaults, deciÂmated the species' numbers to the point of near extinction.
A third of condors suffer from lead poisoning
Today, most of these problems have been ameliorated. But one huge hazard remains: the leading cause of mortality to condor populations and the number one threat to condor recovery is still lead poisoning from spent ammunition.
A 2012 study by the University of California at Santa Cruz by Myra Kinkelstein and others found that "condors in California remain chronically exposed to harmful levels of lead."
"30% of the annual blood samples collected from condors indicate lead exposure (blood lead ≥ 200 ng/mL) that causes significant subclinical health effects ... Furthermore, each year, ~20% of free-flying birds have blood lead levels (≥ 450 ng/mL) that indicate the need for clinical intervention to avert morbidity and mortality."
Continue reading at ENN affiliate, The Ecologist.
Condor image via Shutterstock.
