Condor population is rebounding nicely

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In 1987, California condors teetered on the brink of extinction. Only 27 condors were left on the planet, and all were housed in two captive breeding facilities in southern California.

If populations of endangered species could be recovered, condors would be the ultimate test. Today, there are approximately 230 California condors fly freely in the wild while another 200 remain in captive breeding programs.

Release sites

In addition to southern California, condors have been released in Arizona’s Grand Canyon and Mexico’s Baja California. Restoring large, slowly reproducing species requires time, patience, and persistence.

Condors, the largest vulture in North America, stand about four feet tall and have a wingspan of 9.5 feet. By comparison, turkey vultures are just a bit taller than two feet and have a wingspan of less than six feet.

Condors mate for life and lay one egg per year. Because the entire nesting cycle can take more than a year, condors do not always breed every year.

Incubation takes 54 to 58 days, the chick remains in the nest for about six months, and then requires another six-to-12 months of parental care. Condors nest under protective rocky ledges and in caves in dry mountainous areas.

Both parents share incubation duties, and after hatching, the parents take turns finding food for the chick. They may fly as far as 150 miles from the nest to find carcasses of deer, cattle, pigs, sea lions and whales.

Despite the low reproductive rate, the condor’s recovery is encouraging.

Though they have few natural predators, lead poisoning is a major concern. Ingesting lead shot and bullet fragments from carrion can be deadly.

California is in the process of outlawing lead ammunition. The partners that have brought condors back from the brink of extinction includes the U.S. Fish & Wildlife Service, U.S. Forest Service, National Park Service, and a variety of state wildlife agencies and regional zoos.

New populations

The goal of the recovery plan is to establish two self-sustaining condor populations, one in California and another in Arizona.

A third population will be kept in captivity. Though it’s great to read about wildlife success stories, anyone with an internet connection can now watch an active nest online.

Cornell’s Lab of Ornithology just launched a nest cam at a site in Los Padres National Forest. The female parent is 21 years old and was hatched at the San Diego Zoo in 1994.

She has been breeding since 2001. Her mate is a six-year-old wild-fledged bird. The chick is now about five months old. Watch the nest during daylight hours at www.cams.allaboutbirds.com.

Another success

Another spectacularly successful recovery of an endangered species is unfolding on the Great Plains.

In the mid-1980s, black-footed ferrets were about to go extinct. Only 24 ferrets remained, so biologists trapped them and began a captive breeding program.

Of the original 24 ferrets in captivity, six died from canine distemper or the plague, leaving behind a global population of just 18 ferrets.

Black-footed ferrets depend on prairie dogs as their primary food, but prairie dog populations have been decimated over the last 50 years by farming interests, habitat destruction, and the plague.

Near extinction

This led to the near extinction of the ferrets. The original captive population of 18 ferrets produced only seven surviving offspring, so genetic diversity of the captive population was a problem.

Fortunately, researchers collected sperm from one of the original founding males and froze it in liquid nitrogen. To date, 135 kits have been born through artificial insemination.

To increase the genetic diversity of the population, researchers recently used the frozen semen to inseminate several females. This essentially reached back in time to inject genes from the 1980s into the present population.

So far, eight kits have been born from the frozen sperm. The goal of the ferret recovery program is to maintain healthy genetic diversity in the population and produce enough ferrets to release into the wild.

Today between 300 and 400 black-footed ferrets occupy 24 reintroduction sites across the Great Plains.

 

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Scott Shalaway, who holds a Ph.D. in wildlife ecology from Michigan State University, writes from his home in rural West Virginia. A former faculty member at Oklahoma State University and the University of Oklahoma Biological Station, he has been writing a weekly nature column for newspapers and freelancing for magazines since 1986. He can be heard on Birds & Nature from 3-4 p.m. Sunday afternoons on 620 KHB Radio, Pittsburgh, or live online anywhere at www.khbradio.com, or on the Tune-In radio app. Visit his website at www.drshalaway.com or contact him directly at sshalaway@aol.com or 2222 Fish Ridge Road, Cameron, WV 26033.

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