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by
Robyn Herian
you were to happen across a coastal cactus wren while wandering around in some of Orange County’s last farmland, he would look at you with unmistakable contempt. He would take a moment to consider your presence, cock his speckled little head, contract his fierce white eyebrows and then emit the most sinister “Charcharcharchar” you will ever hear. He might be staring you down from atop the branches of the Mexican elderberry tree that is swaying slightly with his weight, while his formidable mate stays below in the family’s prickly pear cactus nest, protecting the children from harm. The nest itself is a football-shaped fortress, covered in crackling, spiky plant fibers and nestled among the menacing thorns of a cactus. When it comes to the safety of his family, the cactus wren doesn’t take chances and he doesn’t make mistakes. He builds decoy nests in the neighborhood to trick his predators while his mate lines the cool and quiet home-nest with feathers so the chicks can nestle, safe and comfortable, against the surprisingly soft interior of their stronghold. The sun blazes in this harsh and desolate coastal sage scrub, and only the fiercest in nature can survive the barren conditions, this cactus wren among them. The bird can live even without water, taking liquid instead from the plant-life that he eats. The cactus wren is tough, and his eight-inch frame certainly doesn’t prevent him from being able to take on the fiercest enemies that the coastal sage scrub has to offer. Until, of course, fire begins to rage.
Fire is like nothing else that a cactus wren has ever encountered, like nothing that it could possibly adapt to. It rages, scorching and unstoppable, through the cactus wren’s carefully defended home in a matter of minutes and then it is gone, moving on to terrorize more of nature’s flammable coastal sage scrub. Seconds ago, the prickly pear cactus housed an entire family, and now it is decimated, black, and empty. The nest, so carefully lined with the mother wren’s own feathers, is melted into nothingness. The cactus wren family is nowhere to be found. It is never seen again.
It is unknown what happens to the cactus wren immediately after its home is destroyed by fire. Organizations that are responsible for overseeing or managing the coastal sage scrub reserves in S outhern California, such as the Nature Reserve of Orange County and the Irvine Ranch Conservancy (IRC), suspect that most of them simply die in the blaze. Other Orange County birds, like the California g natcatcher, have been similarly affected by coastal sage scrub fires, but unlike the gnatcatcher, the coastal cactus wren population has been unable to recover because its habitat of prickly pear and cholla cactus does not regrow fast enough on its own. Cactus wrens will only make nests in cacti that are more than a meter tall; they don’t feel safe from ground predators in anything shorter. Because it takes the slow-growing cacti around twenty years to reach this height, it is no wonder that this particular bird, with its nesting preferences, has a harder time recovering from habitat destruction than other avian species. This S outhern California burn area is home to the only coastal variety of cactus wren in existence, so if the habitat is not restored, the cactus wren faces local extinction . Aware of this possible loss, the Nature Reserve of Orange County and the Irvine Ranch Conservancy have stepped in with a plan to restore fire-wrecked cactus wren habitats in Orange County.
After the Santiago fire of 2007, a staggering seventy-five percent of the cactus scrub inhabited by the cactus wren in the 20,000 acres of their central reserve was burned to the ground. In 1993, the similarly destructive Laguna fire burned seventy-five percent of the 17,000- acre coastal reserve. The coastal and the central reserves are the only two protected locations in Orange County inhabited by the coastal cactus wren. Since this species of bird has a particularly difficult time adapting to a new environment, such decimation makes it nearly impossible for the cactus wren to recover on its own. In 2008, surveys conducted by the Nature Reserve of Orange County revealed that there were only 67 territories occupied by the bird in the central reserve, down from 374 territories in 2006. Similar surveys of the coastal reserve show that 186 acres were occupied by cactus wrens in 2006, down from the 1,473 acres occupied in 1992. This means that the central reserve and the costal reserve have respectively experienced 82.1% and 87% declines in cactus wren populations since the fires blazed through their lands.
Although the Laguna and Santiago fires were immediately destructive, their long-term effects on the coastal sage scrub ecosystem are just as damaging to the cactus wren’s chances of survival as was the initial burning of their homes. Surveys have found that even in the areas where much of the cacti managed to survive the fire, populations are still rapidly decreasing. Biologists at the Nature Reserve attribute this to the destruction of other important parts of the delicately balanced ecosystem that a cactus wren depends on for survival.
“They don’t have enough food sources to raise their young,” says Kris Preston, a biologist who has been at the Nature Reserve for the last two years. The destruction of other native vegetation leaves the coastal sage scrub inadequate as a food source to the wren, which depends on seeds, insects and small animal life for survival. Drought conditions in the last several years have exacerbated this problem—plant life has been unable to recover and cactus wren populations consequently drop.
Even before the destructive fires, the Nature Reserve of Orange County and the IRC targeted the cactus wren as a species of concern. Urban development in Orange County is slowly consuming the cactus wren’s natural habitat.
Not only does human expansion encroach on natural coastal sage scrub, it also plays a major role in causing the devastating fires. There is a direct link between population and fire—a man who flicks a cigarette butt out of his car window on a highway surrounded by brush can start a fire that will burn thousands of acres and he will never even know that it happened.
“People might be out there with their power mowers at the wrong time of year and spark something. You might have people out there driving…catalytic converters malfunctioning are a big source of fire,” says Preston. People start fires. And that’s a fact without even considering the effects of arson—there were 10,674 California arson crimes in 2008 alone. Not only do people physically ignite fires, increases in population also accompany an introduction of flammable, non-native vegetation to the coastal sage scrub. According to Preston, urban development tends to introduce foreign weeds—weeds that are much more flammable than the native vegetation that surrounds them. “Native vegetation is flammable and will burn, but it doesn’t start up and carry like this grassy stuff that you see at the side of the road and near people’s houses. We’ve changed the environment,” says Preston. The extra flammability combined with drought conditions is especially lethal—dead, dried-out bushes and plants provide even more sustenance for an inferno.
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