Surface mining activities can have cascading effects within sagebrush ecosystems, fundamentally altering multiple components such as soil composition, topography, vegetation communities, and ultimately wildlife populations. Despite the potential for significant disruption of ecosystem function and species composition, surface mining impacts within sagebrush ecosystems are relatively understudied. We quantified the disturbance footprint and duration of operation for all surface mines within Nevada. We then assessed changes in vegetation communities and sage-grouse populations at varying distances from mine sites during active mining operations, post-mining operations, and post-mine reclamation at each site. We found that vegetation communities were substantially altered at mining locations, with the presence of woody shrubs declining following mining operations, even after reclamation was completed. Further, we found that sage-grouse population annual rates of change (λ) declined near mining sites, with substantive declines in λ detected up to 8 km from mining sites, even after active mining operations had ended. Ultimately, we demonstrate evidence that surface mining alters sagebrush vegetation communities and affects sage-grouse populations during and following active mining operations and extending even beyond reclamation. Results can inform conservation efforts to mitigate impacts of future mining operations. Information is preliminary and provided for best timely science.

Climate change is a primary threat to greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), however the mechanisms by which climate affects sage-grouse may be numerous. We reviewed and synthesized the literature describing effects of climate on sage-grouse demography and population performance. Variation in precipitation, drought, and soil moisture underlie patterns of herbaceous growth, protective cover, and food availability across sage-grouse life stages. Nest site selection and nest survival increase with vegetative cover, but most strongly in more-xeric regions, and nest survival may also be sensitive to residual grass cover driven by lagged effects of precipitation. Sage-grouse brood survival and recruitment are sensitive to the availability of mesic habitat resources that are recharged by winter snowpack. Anthropogenic stressors interacting with climate change are altering these ecosystem dynamics. Invasion by annual grasses limits soil moisture for native perennial vegetation, dampens the association between precipitation and sage-grouse population growth, and initiates positive feedbacks with wildfires that impose acute negative effects on sage-grouse demography and cumulative losses of carrying capacity. Given that increasing temperatures and intensified drought cycles are predicted, management to maintain and restore hydrological function would likely benefit sage-grouse persistence in moisture-limited sagebrush ecosystems. Information is preliminary and provided for best timely science.

During brood-rearing, greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) utilize heterogeneous upland meadows that hold moisture and support important food resources. Brood-rearing habitat may become fragmented with widespread habitat loss across the range due to invasion of annual grasses, conifer expansion, and anthropogenic development. We sought to understand impacts of these stressors on sage-grouse brood habitat as these disturbances threaten long-term productivity and population viability. An 11-year study of brood-rearing habitat at 12 sites across the Great Basin demonstrated that increasing annual grass negated positive effects of burned areas on brood survival when annual grass was dominant, highlighting the importance of heterogeneous vegetation communities for sage-grouse broods. Brood-rearing sage-grouse from 10 sites within the Bi-State Distinct Population Segment likely face trade-offs, wherein the need for forage-rich mesic resources at higher elevations may necessitate weakened avoidance of conifers, with consequences for survival. The importance of mesic resources, especially during dry years, was also evident within the Long Valley subpopulation of the Bi-State, where brood survival was positively influenced by the availability and condition of managed mesic resources. Taken together, these findings shed light on the influences of altered landscapes on sage-grouse brood-rearing habitat. Information is preliminary and provided for best timely science.

Greater sage-grouse (Centrocercus urophasianus) are experiencing elevated nest predation from common ravens (Corvus corax) across their range. Previous research indicates that manipulating raven breeding success by oiling raven eggs (preventing raven chicks from hatching) results in increased sage-grouse nest survival probabilities, but the effect of oiling raven eggs on sage-grouse population growth rates remains unclear. We addressed four questions regarding the effect of egg-oiling on overlapping sage-grouse populations. First, we experimentally showed that oil applied to eggs caused embryonic failure rather than the nest disturbances associated with flushing and spraying eggs with water. Second, we found that causing raven nests to fail by oiling eggs was associated with a decline of raven densities at treatment sites relative to control sites. Third, we confirmed previously published findings that oiling eggs was followed by an increase in sage-grouse nest survival probabilities. Finally, we tested whether oiling raven eggs led to population growth of overlapping sage-grouse populations at treatment sites using a Before-After-Control-Impact design. While questions regarding long term effects remain, wildlife managers can use egg-oiling to help manage overlapping populations of ravens and sage-grouse, and potentially other sensitive prey. This information is preliminary, subject to change, and provided for best timely science.

Release from interspecific competition can lead to niche shifts and have positive fitness consequences. I studied two closely-related and ecologically similar Empidonax species that breed across an elevational gradient in the southern Sierra Nevada: the Dusky Flycatcher (Emidonax oberholserii) and the Hammond’s Flycatcher (E. hammondii). Both species coexist at low and moderate elevations but only Dusky Flycatchers occur in high elevation forests where they are abundant. My objective was to examine niche shifts and possible fitness consequences in Dusky Flycatchers breeding where their potential competitors are absent. Hammond’s Flycatchers nested exclusively in trees while Dusky Flycatchers generally nested in shrubs at low and moderate elevations, but at high elevations they switched their nest location to that of Hammond’s Flycatchers. This suggests ecological release, where Dusky Flycatchers shift to the nesting niche of Hammond’s Flycatchers where they are absent. Nest survival for both Hammond’s and Dusky flycatchers increased with nest height, suggesting that nesting in trees is beneficial for both species. The advantages to nesting at higher elevations are likely complex and not solely related to changes in nest location and elevation. Studying species that segregate along environmental gradients may help us understand and better predict species’ responses to climate change.

The California Department of Fish and Wildlife (CDFW) mourning dove (Zenaida macroura) banding program monitors and manages populations of mourning dove across the state to ensure population stability of the species. This mark-recapture program also serves as an important Citizen Science opportunity, where approximately 100 staff and volunteers participate each year. From 2008 to 2023 a total of 54,884 mourning dove have been banded, with 10% (n=5,500) having been recaptured and 4.85% (n=2,664) having been reported. A majority (n=2,457) of banded mourning dove reported have been from hunters, including birds harvested in Mexico. These reports account for 4.7% of all banded dove. Banders classify birds to age, which provides information on annual recruitment. Across all years, hatch year to after hatch year ratio was 0.89:1. A subset are classified as unknown age based on stage of molt. The 2023 banding season concluded with 1,684 mourning dove banded across 52 sites. We will present an overview of distance between capture, recapture, and/or harvest location. This program provides critical data for CDFW and the Pacific Flyway to manage the mourning dove population as both a popular yard bird and a sustainable upland game bird for future generations.