Assessment of Chukar and Gray Partridge Populations - Idaho Power

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Hells Canyon Chukar and Gray Partridge Report, Ratti and Giudice 20similar to that of Great Britain where most nesting occurred in some type of linear cover or fieldborder (Carroll et al. 1990). In North Dakota, dominant vegetation at roadside nests includedsmooth brome (Bromus inermis) and several woody shrubs (e.g., Rosa spp. and Symphoricarposoccidentalis; Carroll and Crawford 1991). In South Dakota, nests sites were dominated bysmooth brome (Hupp et al. 1980). In Great Britain, hedgerows were important, although theamount of dead grass at the base of hedgerows influenced breeding density (Potts 1986, Rands1986). The importance of residual herbaceous growth for nesting cover (especially initialnesting attempts) was also noted by Yeatter (1934), Knott et al. (1943), McCabe and Hawkins(1946), and Mendel (1979). In Washington, Swanson and Yocum (1958) suggested highpartridge populations were maintained because birds utilized wheat stubble in place ofbunchgrass. In general, gray partridge selected grass-dominated nesting sites. Forb-dominatedcommunities, such as alfalfa fields, were not preferred nesting habitat, but offer some of theearliest spring cover when residual grass cover is absent (Weigand 1980). Availability ofpermanent nesting cover may be an important limiting factor in intensively farmed areas such asthe Palouse Prairie (Mendel 1979, Rotella et al. 1996), but nesting cover probably is not limitingin canyon grasslands such as Hells Canyon.4.5.3. Brood-rearing4.5.3.1. Chukar. Limited data are available on habitat use by chukars withbroods. Oelklaus (1976) reported that as spring progressed into summer, unsuccessful hensjoined male flocks and older broods began to aggregate. Summer heat and drought conditionsdrew smaller groups together near remaining available water. During this period, the greatestnumbers of chukar were closely associated with the Snake River and its riparian habitats(Oelklaus 1976). Likewise, Christensen (1970) concluded the summer distribution of chukar inNevada depended a great deal upon the distribution and availability of water. However, despitethe tendency of birds to be near water during most of day in hot weather, occasional broods andaccompanying adults were found during the early morning hours on hillsides >1 mile from theclosest known surface water (Christensen 1970). In Washington, Galbreath and Moreland(1953) reported that during May and early Jun, broods were often found in small side canyons(i.e., tributaries to the main canyon).Rock cover may be important for nesting, but it does not appear to be important for broodrearing. Galbreath and Moreland (1953) observed that young chukars (5% yellow-star thistle, butpotential effects of yellow-star thistle on productivity needs further investigation (Lindbloom1998).
Hells Canyon Chukar and Gray Partridge Report, Ratti and Giudice 214.5.3.2. Gray Partridge. Data are lacking on brood ecology of gray partridge inHells Canyon or other canyon grasslands. However, habitat use by broods is thought to bemainly influenced by food availability (especially arthropods) and vertical habitat structure(Green 1984, Enck 1986). In North Dakota, Carroll et al. (1990) reported that young broods (
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Assessment of Chukar and Gray Partridge Populations - Idaho Power

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