Thursday, August 26, 2010

Paisano Bird: Greater Roadrunner

Greater Roadrunner, the New Mexico state bird. Photo by Doug Brown.

Overheard at a rest area from a group of tourists from the north: “Friend, have you seen that bird that runs on the ground instead of flying? You know, the one that slams lizards onto the ground until they die! What is it?” Anyone who has seen the Greater Roadrunner scuttling through desert scrub, trotting down the roadside, or calling mournfully from atop your rooftop swamp cooler needs no elaborate name to remember it.

Indeed, our state bird, the Greater Roadrunner, a member of the cuckoo family, is not only fascinating in his habits, it also is the subject of myths and folklore. One of the best myths is that the roadrunner traps sleeping rattlesnakes by encircling them with cholla cactus sections. As soon as the corral is complete, the bird wakes up the snake by dropping a piece of cactus on it. Then, when the snakes tries to escape, it is fatally injured on the spines, an easy meal for an opportunistic bird. Perhaps it is stories like these that were responsible for the roadrunner/coyote cartoons in which the roadrunner always outsmarted the coyote.

The Greater Roadrunner has been credited with supernatural powers too, and has been called War Bird, Snake Eater, or Medicine Bird. Petroglyphs of the bird occur in the canyons of southern New Mexico and, in Arizona, the Hopi used symbol “X,” depicting the distinctive track of their zygodactyl foot, on Kachina figures to ward off evil spirits. Because two toes face forward and two back, the spirits cannot follow Roadrunner because direction of its travel is unknown.

In Pueblo culture, a safe afterlife is ensured by placing roadrunner tracks around the house of the dead in order to mislead evil spirits as to course taken by departed soul. Roadrunner feathers provide good luck and confuse evil spirits, and also symbolize courage, strength, and endurance. Many American Indian tribes ate roadrunners to acquire stamina and swiftness. In Mexico, roadrunner flesh was thought to cure itch and boils, purify blood, and stimulate growth in flowers. And, the Greater Roadrunner takes the place of stork in bringing babies. There is simply no end to the tales that surround the signature bird of the desert southwest.

With special adaptations that allow it to thrive in the hostile environment of the arid southwest, the Roadrunner thrives and can be found north into southeastern Colorado, west to the Pacific Ocean and east to western Louisiana. An opportunistic predator, it feeds on snakes, lizards, spiders, scorpions, snails, insects, birds, rodents, and bats, which it beats repeatedly against a hard substrate before consuming. The beating pulverizes the prey so it can be swallowed whole as the roadrunners bill does not allow the bird to tear apart its food. Quick learners, they capture small birds at feeders and nest boxes, with a seeming preference for unwary hummingbirds. One was observed leaping from a hiding spot in a dry riverbed to capture a low-flying White-throated Swift.

Built for life on the run, the roadrunner can reach running speeds of 18 miles per hour holding its head and tail flat and parallel to the ground to reduce wind resistance. Roadrunners prefer running over flight and generally only take flight when threatened or to reach a higher perch. Because of the preference to run, one of the major causes of mortality is collisions with vehicles. Further adaptations suited for life in an arid environment include:

  • Black skin that absorbs sunlight: A roadrunner will turn its back to the sun, fluff its feathers, and expose the skin along its back to warm up.
  • Salt glands in the eyes excrete excess salt from the blood. These glands are common in ocean-going birds that drink seawater. The roadrunner gets most of its fluid needs met from eating live prey with a high water content, although they also drink water when it is available

Ever the clever bird, the male Greater Roadrunner withholds food from the female until after the deed is done!” Photo by Carolyn Sanborn.

Populations are slightly declining according to long term studies, Perhaps the greatest threat is due to urbanization and the associated loss of habitat. The vegetation found in many urban landscapes lacks the structure necessary for foraging and may be inappropriate for nesting. Roadrunners are particularly sensitive to disturbance when nesting, and have been known to abandon their nests after even a single visit from a human. Predation by household and feral cats takes a toll as well, particularly on recently fledged young.

Greater Roadrunners are monogamous, maintain long-term pair bonds, and mutually defend a large multipurpose territory that just might include your yard. Roadrunners are hugely popular in the neighborhoods where they occur, and in some areas have been handfed by well-intentioned people. However; roadrunners are true carnivores, with nutrient needs that can only be met by consuming whole animals or insects. While a roadrunner may eat meatballs set out by us, in addition to having a high fat content, ground meat lacks the critical nutrients necessary for the bird’s survival. So resist the urge to build a closer relationship with the seeming friendly fellow, as fascinating as he might seem.

Monday, August 16, 2010

Ghost Story

Barn Owls in Flight. Images by Doug Brown

It had been a long night, with one incident crescendoing onto another and it was later than usual when Sarah finally turned off the lights and locked the door. With her pack fully loaded with books, she stepped briskly down the stairs to begin her walk home. Although Sarah was a remarkably confident woman, her steps always quickened as she passed the boarded up, decrepit building adjacent to the cemetery, and tonight was no different. Suddenly, she stopped dead in her tracks as the sound of a large object hitting the floor emanated resoundingly from the old house. A bloodcurdling shriek accompanied the pronounced clank and, as she stood frozen in place, a white form emerged from the broken panes of the upstairs dormer window and flew right over her head. The blood drained from her brain as her heart pounded thunder in her ears, Sarah knew not whether she should cower or flee. A ghost, warning her of impending doom? Or, was there a more practical explanation?

The Barn Owl, more than all other owls, is heavily associated with superstition and mythology. The species is sometimes called the Ghost Owl, Death Owl, or the bird of doom due to its nightly hunting habits, the fact that it is white below, and its vocalizations that include the voluminous, unearthly shriek. Living up to its name, it often roosts and nests in abandoned buildings, beneath bridges, and in New Mexico, in cavities in arroyos and canyons. It is heavily referenced in superstition, and in ghost and Halloween stories. Barn Owls also are featured prominently in literature and art, most recently in the Harry Potter stories by J. K. Rowling that portrayed owls as messengers for the witches and wizards of Hogwarts.

Barn Owls were thought to be the animal familiars of wizards and witches, and some witches were even said to ride on owls rather than broomsticks. In some societies, Barn Owls were considered harbingers of death and their cry a warning that someone was soon to die. Others believed that the owls cursed people, were responsible for the deaths of babies, and were the Devil’s companions, able to make clairvoyant predictions. Some Native Americans believed that evil people were reincarnated as Barn Owls when they died.

But, like all other wildlife, this owl is just doing what comes naturally, surviving. Their secretive nature renders them inconspicuous to most people, so it is not surprising that individuals who do encounter this bird are startled. It is its appearance, combined with some particular behaviors, that make the bird so frightening. The Barn Owl is the most nocturnal of all birds, and can hunt in almost zero light levels. During daylight hours, it sleeps in a secluded cavity such as an abandoned building, in a cavity or under a bridge. This affords the owl some peace while it dozes throughout the day, for an exposed owl of any species is certain to be relentlessly mobbed by attacking, highly vocal songbirds, including crows and ravens. It emerges from its roost only after the last vestiges of day are gone, winging over open areas to hunt for rodents.

Like all owls, Barn Owls fly silently, coming without warning upon their prey—and sometimes upon humans who also are outside in the dark. Their breast and the underside of their wings are whitish, giving them a luminescent and ghostly appearance against the night sky. And, lastly, their vocalizations include hisses and clicks, and the infamous ghoulish, drawn-out shriek that is abruptly cut off.

Declining populations in several areas have raised public awareness of the species. They are a short-lived species with an average life span of less than two years. Birds begin breeding at age one and can produce two broods per year with up to eight young per clutch (in New Mexico).

Collisions with vehicles are a major cause of mortality, in the U.S. as well as in other developed parts of the world. One British study reports that Barn Owl mortality attributed to road kill increased from 6% in 1910-1954 to 50% in 1991-1996; major roads caused the complete extinction of breeding Barn Owls within 1/4-1-3/4 miles of such roads and some depletion from roads up to 5 miles distant. Another cause of mortality, pesticide contamination, particularly from secondary poisoning of anticoagulant rodenticides, occurs when the owls consume poisoned rodents. However, potentially more damaging is the loss of foraging areas and/or prey populations due to urban sprawl and changing agricultural practices.

A few years ago, I investigated an old abandoned shed in the Estancia Valley. Upon approach, I knew that owls lived there. Ample evidence in the form of blackish clods of dried pellets littered the ground beneath the overhanging eaves of the building. Once inside, it would have been easy to imagine a ghostly presence for whitewash, another word for owl excrement, coated the walls and dripped from the rusted bedsprings in what would have been the attic. To my dismay, no owls were home that day, and I could only imagine the ghost story I would have told if it had turned out differently.