Lifeform of the week: California condors are making a comeback
There aren’t that many California condors in existence, but the ones out there are hard to miss. You can spot them by their striking bald heads accessorized with glamorous feather boas, their massive wings, and, of course, the conspicuous numbered conservation tags dangling from them. A type of vulture, the birds were saved from extinction by an unprecedentedly ambitious conservation program, making Gymnogyps californianus not only one of the largest species gracing our skies, but also the most expensive.
Flight of the Condors
With a wingspan of almost 10 feet, the California condor is the largest land bird in North America.* If that doesn’t already sound absurdly enormous, let me remind you that the bald eagle, symbol of all the purported power and majesty of the United States, soars on wings that barely measure 8 feet from end to end.
Not surprisingly, the California condor’s flying abilities are impressive. The bird can reach heights of 15,000 feet (nearly 3 miles!) and speeds of 55 mph. The vast wingspan allows them to glide for over an hour without flapping. While they spend more time roosting than in the air, they can easily cover over 100 miles over a single day in search of food.
Like all vultures, California condors live on found carrion (i.e. dead animals). They prefer freshly-killed meat and large portions – big animals such as cattle and deer – but will partake of smaller and more rotted carcasses if nothing better is available. Strong stomach acids make it possible for the birds to scarf down a multitude of bacteria that would sicken or kill our own species (anthrax and cholera, to name a couple). The absence of feathers on the head is another adaptation to a diet composed of meals in various states of decay. Bald heads are much easier to clean after plundering the depths of putrefying road kill. Despite public perception of their being, well, kind of gross, vultures spend a good deal of time bathing and preening their feathers. Though if you need another item to add to the gross list, they also remove bacteria from their feet through an activity called urohydrosis.†
Home on the Range
Once upon a time, California condors could be found all along the Pacific coast and other portions of North America, but today their range is mostly restricted to southern California and Arizona. They are often found along rocky cliffs, which they favor for nesting.
Gymnogyps californianus is not a migratory species. Once the condors settle down with a mate (they are monogamous and mate for life), they will return to the same nest despite their broad-reaching food runs. They reproduce slowly, reaching 6 years of age before even beginning to breed. Females lay a single egg only every other year. Parental responsibilities are shared by both parents.‡ If they manage to avoid various health threats, California condors can live up to 60 years.
Sadly, these threats are numerous, and by the early 1980s things were not looking good for the California condor. After decades of population decline, only about 20 individuals remained in the wild. With the species on the verge of extinction, the U.S. government took a drastic step and approved what would become the most expensive species conservation project in U.S. history – the California Condor Recovery Program. The lofty project aimed to establish two populations, one in California and another in Arizona. This was to be accomplished by rounding up the remaining wild condors (the last one was captured in 1987), breeding them in captivity, and eventually releasing them into the wild. To maximize the number of new condors produced, some of the chicks are raised by a human-controlled puppet parent, so that the real moms and dads can care for a second hatchling. While being reared in captivity, the birds are also trained to stay away from power lines, a well-known hazard of the outside world. Today, between 100 and 200 California condors exist outside of captivity. But theirs isn’t such a wild lifestyle. The animals’ stately wings are blemished with the clunky numbered tags necessary for scientists to monitor their movements, and they are quickly recalled to headquarters for medical attention at the first sign of distress.
One potentially-preventable peril affecting the California condor is lead poisoning. As scavengers, the birds sometimes consume the remains of animals killed by hunters, whose traditional ammunition is composed of lead. Efforts to ban lead ammunition are ongoing. In 2010, the EPA denied a petition for a nationwide ban on the toxic bullets. However, states are free to create their own bans, and, despite much criticism from the gun lobby, California has outlawed the use of lead ammunition in much of the condors’ range. California’s legislation took effect in 2008, and last week – April 6, 2011 – researchers at UC Davis published a study that found a significant decrease in lead exposure among other scavenging birds in California condor range following the ban.§ Additionally, in March of 2011, a UC Santa Cruz study was presented at the annual meeting of he Society of Toxicology that showed lead ammunition to be a major hindrance in the recovery of California condors. Conservation advocates are hopeful that such studies will provide the data needed to widen protection for these birds.
Why We Need Vultures
Regardless of how you feel about an animal that eats road kill and craps on its own feet, it’s hard to deny the benefit to human society provided by scavenging birds. One California condor can consume as much as three pounds of meat a day. That’s a lot of dead animal flesh that would otherwise be stinking up our roads and breeding armies of disease-causing bacteria. In the absence of avian carrion-eaters, mammals such as feral dogs have been known to pick up the slack, but this can lead to a rise in large predators (wild cats, for instance) that prey on dogs. Such ecological shifts can increase the risk of rabies, as well as animal attacks on humans. India experienced these harsh realities over the last decade, after a sharp decline in its vulture population due to poisoning from Diclofenac, a drug used in livestock farming. Vultures are as important to human existence as trash collectors (which is to say, vastly important). And while the California condor isn’t the only scavenging bird in North America, it is certainly among the most dazzling.
* South America’s Andean condor beats it out by roughly a foot of additional wingspan.
† This involves urinating/defecating (it’s an all-in-one process for birds) directly onto their feet. The uric acid in their droppings is a disinfectant, like the ammonia in some household cleansers. Not that I’m recommending you try it yourself, but urohydrosis can also help birds cool their feet on warm days.
‡ If an egg is taken from the nest, the female will produce another. Scientists have used this tendency in efforts to increase the species’ population.
§ A second UC Davis study published simultaneously reported a significant increase in lead exposure in turkey vultures (“buzzards”) during deer hunting season – which confirms lead ammunition specifically as a source of lead poisoning in carrion-eating birds.