Weather, habitat composition, and female behavior interact to modify offspring survival in Greater Sage‐Grouse

Abstract

Weather is a source of environmental variation that can affect population vital rates. However, the influence of weather on individual fitness is spatially heterogeneous and can be driven by other environmental factors, such as habitat composition. Therefore, individuals can experience reduced fitness (e.g., decreased reproductive success) during poor environmental conditions through poor decisions regarding habitat selection. This requires, however, that habitat selection is adaptive and that the organism can correctly interpret the environmental cues to modify habitat use. Greater Sage-Grouse (Centrocercus urophasianus) are an obligate of the sagebrush ecosystems of western North America, relying on sagebrush for food and cover. Greater Sage-Grouse chicks, however, require foods with high nutrient content (i.e., forbs and insects), the abundance of which is both temporally and spatially dynamic and related primarily to water availability. Our goal was to assess whether nest site selection and movements of broods by females reduced the negative effect of drought on offspring survival. As predicted, chick survival was negatively influenced by drought severity. We found that sage-grouse females generally preferred to nest and raise their young in locations where their chicks would experience higher survival. We also found that use of habitats positively associated with chick survival were also positively associated with drought severity, which suggests that females reduced drought impacts on their dependent young by selecting more favorable environments during drought years. Although our findings suggest that female nest site selection and brood movement rates can reduce the negative effects of drought on early offspring survival, the influence of severe drought conditions was not completely mitigated by female behavior, and that drought conditions should be considered a threat to Greater Sage-Grouse population persistence.

Nest and brood site selection of eastern wild turkeys

“…Contemporary research has noted declining productivity of turkeys throughout the southeastern United States (Byrne et al ), and fire affects vegetation and landscape composition in ways that could affect nest and brood survival. Predation is the primary cause of nest (Byrne and Chamberlain , Kilburg et al , Little et al , Yeldell et al ) and brood loss (Speake et al , Palmer et al ), and predation risk likely operates across multiple spatial scales (Fleming and Porter , Gibson et al ). Because fire affects vegetation composition across landscapes, it could influence predation rates and nest survival (Yeldell et al ).…”

Influences of potential oil and gas development and future climate on Sage‐grouse declines and redistribution

“…, Gibson et al. ). As our future climate analyses focused only on precipitation change, future research at broader spatial extents would benefit from the development of vegetation forecasts that incorporate both temperature and precipitation to refine expected habitat outcomes.…”

Seasonal drought in North America’s sagebrush biome structures dynamic mesic resources for sage‐grouse

“…For example, in the Great Basin, distances between mesic sites were double in comparison to other regions (Figure ) due to nonlinear patterns of intensifying drought that concentrated available mesic resources in wet meadow valley bottoms and high elevation rangelands (Figure ), effectively extending the distance that young have to move between productive mesic sites to forage. Increased movements compound drought effects and are a factor known to lower brood survival (Gibson et al, ).…”

“…The new dataset introduces geographic scale and perspective to ecological drought and its relationship to sage‐grouse that to this point remain unexplored. Results provide a framework that for the first time links local evidence‐based studies to rangewide drought effects influencing demographic constraints in sage‐grouse populations (Blomberg, Sedinger, Atamian, & Nonne, ; Blomberg, Sedinger, Gibson, Coates, & Casazza, ; Gibson et al, ; Guttery et al, ). Study outcomes deliver new insight to support development of regionally specific conservation strategies necessary to offset drought‐induced bottlenecks impacting sage‐grouse and other drought sensitive wildlife in sagebrush ecosystems.…”

“…Sage‐grouse are representative of spatial patterns in drought‐induced ecological minimums, as productive mesic sites in late summer provide an important, but limiting food resource that structure sage‐grouse abundance and distribution within broader landscapes (Donnelly, Naugle, Hagen, & Maestas, ). Significant temperature increases across western North America in recent decades (Melillo, Richmond, & Yohe, ) now threaten availability of mesic resources that have foreshadowed growing concerns of deepening drought and its effect on sage‐grouse populations (Gibson, Blomberg, Atamian, & Sedinger, ; Guttery et al, ).…”