Birds of the Sierra Nevada. Ted Beedy
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Greater Sage-Grouse
Centrocercus urophasianus
ORIGIN OF NAMES “Sage-Grouse” for their dependence on sagebrush; Gr. centrocercus, sharptailed; urophasianus from Gr. oura, tail, and L. phasianus, a pheasant.
NATURAL HISTORY Perhaps the most inspiring Sierra birding experience is waking up in the predawn chill to view the elaborate and spectacular strutting displays of the Greater Sage-Grouse, the largest native North American grouse. As soon as the snow starts to clear in early March, males gather at traditional “lek” sites to attract females on open hillsides, grassy swales, recently burned areas, or dry lakebeds, surrounded by sagebrush—the species’ preferred nesting habitat. Leks are collective display grounds composed of small, individual territories defended by different males. Strutting displays involve a complex sequence of stereotyped postures characterized by vertical fanning of the long, sharp tail feathers, lowering of wings, and inflating of air sacs to display two olive-green skin pouches. Individual displays last about three seconds but are repeated many times during the early dawn hours. Breeding displays also include an array of strutting calls, fighting calls, low grunts, and loud popping sounds.
Displays and vocalizations serve as an alternative to physical aggression, and displaying males rarely engage in direct physical combat with other males. Leks consist of 20 or more competing males and the oldest ones, “master cocks,” are the most successful. Typically one or a few males achieve more than 90 percent of all copulations. Clusters of hens gather together and serve as a sexual stimulus for other females that engage in precopulatory squatting before accepting the advances of the dominant males. After hours of preparation, the copulation only lasts a few seconds. Birders and photographers should exercise extreme caution when viewing Sage-Grouse strutting displays and should only view them from well-concealed sites at a distance of 100 yards—or more.
Once fertilized, the hens leave the strutting grounds and seek out nesting sites under the overhanging cover of sagebrush or tall grasses to provide thermal cover and protection from predators. Hens care for their precocial young for at least several weeks. Young are capable of foraging on their own within a few hours of hatching, and insects such as ants and beetles are an important component of their diet. Preferred foods of adult Sage-Grouse include the fresh leaves and buds of sagebrush as well as grasses, flowers, fruits, and a few insects; in winter, Sage-Grouse subsist entirely on sagebrush leaves, a diet unique among North American birds.
STATUS AND DISTRIBUTION Greater Sage-Grouse are residents of sagebrush flats in the Great Basin, and their range extends into the eastern Sierra.
West Side. No records.
East Side. Uncommon to rare and highly localized; some lek sites in the region persist at isolated locations near Honey Lake, west of Bridgeport Valley, Mono Basin, and Long Valley (Mono County); also just east of the Sierra in the Bodie Hills and White Mountains (Mono and Inyo Counties).
TRENDS AND CONSERVATION STATUS Due to their dependence on sagebrush, Sage-Grouse are adversely affected by land management activities that degrade their habitat, such as overgrazing by cattle and wild horses, unnatural colonization of sagebrush habitats by Utah junipers and pinyon pines, uncontrolled and destructive wildfires, and fragmentation by roads and housing subdivisions. Historical hunting pressure was also a factor in the species’ decline, but strict controls since the 1980s suggest that hunting is not a current threat to their population. Such recreational activities as off-highway vehicles and uncontrolled viewing and photography of active leks can result in reproductive failures. “Green energy” projects, such as solar and wind, that destroy thousands of acres of pristine desert or sagebrush habitat, are also a significant but unmeasured threat. For these reasons, the species was included on the 2008 list of California Bird Species of Special Concern.
White-tailed Ptarmigan
Lagopus leucurus
ORIGIN OF NAMES “White-tailed” for the species’ distinctive field mark; “ptarmigan” is probably derived from a Gaelic word “tarmachan,” the “p” is silent and based on historical misspelling; Gr. lagopus, hare-footed, a reference to the species’ feathered tarsus and feet; Gr. leucurus, white-tailed.
NATURAL HISTORY Brown and white in summer, these Arctic grouse molt into pure white plumage in winter to match their snowy surroundings. White-tailed Ptarmigan are silent most of the time, but both males and females utter loud “flight screams” when flushed, and territorial males emit “gobbling” calls to attract females. Males are generally monogamous, but some are polygynous and court two or more females. Pair formation begins from late April to mid-May. After copulation, females use their feet and bills to excavate shallow scrapes on the ground near rocks in snow-free areas. These are later filled with nearby stems and grasses to form a shallow bowl. Typically females lay one egg per day, but during severe snow storms up to eight days may lapse before another egg is laid. The young are brooded by both parents until they can fly and forage alone; broods remain together until the following spring.
White-tailed Ptarmigans are native to Alaska, western Canada, and isolated pockets of the Rocky Mountains—but not the Sierra. The California Department of Fish and Game introduced White-tailed Ptarmigans to the Sierra simply because the Alpine zone had no game birds for hunters. This is especially ironic because nearly all currently inhabited sites are in National Parks where hunting is prohibited. Although there is no documentation of detrimental effects of this introduction, ecologists have long known that non-native animals can have unpredictable, and sometimes disastrous, effects on native plants and animals, which have coevolved over thousands or millions of years.
STATUS AND DISTRIBUTION All White-tailed Ptarmigans in the Sierra originated from a transplant of about 70 birds from Colorado released at two sites near Eagle Peak and Twin Lakes, Mono County, in 1971 and 1972 (Frederick and Gutiérrez 1992). Since then, the species has spread to about 50 miles north, 20 miles west, and 70 miles south of the release sites.
West Side. Uncommon residents; recorded in Humphrey’s Basin and Dusy Basin in Kings Canyon National Park and as far north as Carson Pass, El Dorado County; breeding populations occur near the crest in the Yosemite Sierra near Gaylor Lakes, Granite Lakes, Mono Pass, and Dana Plateau, and as far west as Mount Hoffman, near the geographic center of Yosemite National Park.
East Side. Uncommon residents, mostly confined to the Alpine zone along the crest, but spring sightings at about 8,000 feet in Lundy Canyon, Mono County, suggest downslope movements in winter to avoid heavy snow; also observed near Pine Creek, Green Lake, Brown Lake, and Piute Pass, Inyo County.
Sooty Grouse
Dendragapus fuliginosus
ORIGIN OF NAMES “Sooty” for dark plumage; formerly called Blue Grouse, now considered a distinct species from Dusky Grouse (D. obscurus); see “Status and Distribution” below; Gr. dendragapus, tree loving; fuliginosus from L. fuligo, sooty.
NATURAL HISTORY Sooty Grouse are more often heard than seen. Males of this species congregate in loose “hooting groups” from late April to early July to proclaim their territories with a series of resonant, booming calls. These calls are lower in pitch than those of any other Sierra bird, so low that some people cannot hear them. Two yellow air sacs on the neck, usually hidden, are inflated to produce these unmistakable notes. Finding a hooting male is seldom easy, because he makes