The use of Mountain Quail vocalizations
to estimate abundance
Habitat distribution modeling
for coastal Sooty Grouse
Mtn Quail Sooty Grouse
Mountain Quail (Oreortyx pictus), photo by Gary Kramer Sooty Grouse (Dendragapus fuliginosus fuliginosus
MOQU project photo gallery
MOQU project final report
SOGR project photo gallery
SOGR  project final report
Period: March 1st, 2016 - February 28, 2017 Period: March 1st, 2016 - February 28, 2017
Location: Stanislaus National Forest, Tuolumne Co., California Location: Glenn, Lake, Mendocino, and Sonoma Counties, California
Funding: California Department of Fish and Wildlife Funding: California Department of Fish and Wildlife
Need: Drought and increased wildfire severity have altered the structure, composition, and distribution of chaparral habitats in the Sierra Nevada Mountains, relative to pre-fire suppression conditions (van Wagtendonk and Fites-Kaufman 2007). These trends will likely continue in the future due to climate change (McKenzie at al. 2003, Westerling et al. 2006), yet their impact on Mountain Quail is essentially unknown. Investigations of Mountain Quail ecology are hindered by the poorly-developed state of assessment methods (Gutiérrez and Delehanty 1999). Mountain quail abundance, for example, has occasionally been assessed by line transect distance sampling and auditory point count sampling (Brennan and Block 1986, Roberts et al. 2011), but line transects are impractical in dense chaparral (Burnham et al. 1980), and auditory censuses rely on assumptions about vocalization behavior that are unproven and questionable (Gutiérrez and Delehanty 1999). Need: Historically, the Sooty Grouse (Dendragapus f. fuliginosus) occurred along California’s Coast Ranges as far south as the Russian River in central Sonoma County (Grinnell 1915). In the early 1940s, Grinnell and Miller (1944) reported it had apparently “disappeared from [the] southern portion of [this] range,” and Burridge (1995) suggested there had been "a sharp decline [in Sonoma Co.] in the 1950s ... coincident with heavy logging of fir trees." The species’ distribution and status have not been adequately assessed south of Humboldt and Trinity counties, even though it is hunted throughout the area except in Sonoma County. The species appears to be vulnerable to extirpation in peninsular habitats (Bland 2013), perhaps because habitat conditions become increasingly marginal toward the tip of the peninsula (Bendell and Zwickel 1984). In order to forestall extirpation of the species at the southern end of the northern Coast Ranges, remaining breeding sites should be identified and managed in a manner that ensures Sooty Grouse occupancy. It is important to inventory breeding sites of the Sooty Grouse because, where the species occurs at low density, it breeds communally, gathering year after year at the same sites (Bendell and Elliott 1967, Lewis 1985, Bland 2013). These are core habitats, and identifying them is essential for managing local populations.
Objectives: To quantify the spatial and temporal patterns of Mountain Quail vocalization that underpin abundance estimates derived from call counts, and to calibrate a detection decay curve for use in occupancy estimation and probabilistic population estimation. Objectives: GBRG will attain accurate coordinate locations for a sample of territorial male Sooty Grouse throughout Mendocino, Glenn, Lake, and Sonoma counties, and use those records to create a habitat suitability model that can predict the locations of additional breeding sites throughout the region.
Benefits: Given the current paucity of experimental research on Mounatin Quail vocalization, this work will potentially become a key reference for Mountain Quail vocalization behavior, and a cornerstone for subsequent Mountain Quail census work. The knowledge acquired regarding temporal variation in vocalization patterns is essential for developing scientifically-defensible point census protocols, and will provide a provisional detectability coefficient for future probabilistic population estimation. The methodological approach we use might also serve as a model for developing auditory census protocols for California’s two other quail species, California Quail (Callipepla californica) and Gambel’s Quail (Callipepla gambelii). Benefits: The field survey will result in a catalog (representative sample) of Sooty Grouse breeding territories throughout the region that will contribute significantly to CDFW’s statewide range map for Sooty Grouse. Habitat modeling will provide a spatially-explicit "heat map" of habitat suitability across the region, which will make future survey work more efficient as well as generate a list of habitat attributes (features of GIS layers) that constitute the characteristic, or discriminatory, patch-scale features of Sooty Grouse habitat in the region. Habitat managers who wish to improve or maintain Sooty Grouse breeding habitat can then manage to optimize those features.