Iconic sagebrush ecosystems of the American West are threatened by larger and more frequent wildfires that can kill facilitate invasion annual grasses, creating a cycle alters ecosystem recovery post disturbance. Thwarting this accelerated grass-fire is at forefront current national conservation efforts, yet its impacts on wildlife populations inhabiting these have not been quantified rigorously. Within Bayesian framework, we modeled 30 y wildfire climatic effects population rates change...

In sagebrush (Artemisia spp.) ecosystems, encroachment of pinyon (Pinus and juniper (Juniperus spp.; hereafter, “pinyon-juniper”) trees has increased dramatically since European settlement. Understanding the impacts this on behavioral decisions, distributions, population dynamics greater sage-grouse (Centrocercus urophasianus) other obligate species could help benefit ecosystem management actions. We employed a novel two-stage Bayesian model that linked avoidance across different levels...

Globally accelerating frequency and extent of wildfire threatens the persistence specialist wildlife species through direct loss habitat indirect facilitation exotic invasive species. Habitat specialists may be especially prone to rapidly changing environmental conditions because their ability adapt lags behind rate alteration. As a result, these populations become increasingly susceptible ecological traps by returning suboptimal breeding habitats that were dramatically altered disturbance....

First posted March 30, 2021 For additional information, contact: Director,Western Ecological Research CenterU.S. Geological Survey3020 State University Drive EastSacramento, California 95819 Incorporating spatial and temporal scales into greater sage-grouse (Centrocercus urophasianus) population monitoring strategies is challenging rarely implemented. Sage-grouse populations experience fluctuations in abundance that lead to oscillations, making trend estimation difficult. Accounting for...

Because sea otters (Enhydra lutris) exert a wide array of direct and indirect effects on coastal marine ecosystems throughout their geographic range, we investigated the potential influence ecology Bald Eagles (Haliaeetus leucocephalus) in Aleutian Islands, Alaska, USA. We studied diets, productivity, density breeding four islands during 1993–1994 2000–2002, when were abundant scarce, respectively. depend nearshore communities for most prey this ecosystem, so predicted that recent decline...

Summary Predictive species distributional models are a cornerstone of wildlife conservation planning. Constructing such requires robust underpinning science that integrates formerly disparate data types to achieve effective management. Greater sage‐grouse Centrocercus urophasianus , hereafter ‘sage‐grouse’ populations declining throughout sagebrush‐steppe ecosystems in North America, particularly within the Great Basin, which heightens need for novel management tools maximize use available...

Fine-scale spatiotemporal studies can better identify relationships between individual survival and habitat fragmentation so that mechanistic interpretations be made at the population level. Recent advances in Global Positioning System (GPS) technology statistical models capable of deconstructing high-frequency location data have facilitated interpretation animal movement within a behaviorally framework. Habitat due to singleleaf pinyon (Pinus monophylla; hereafter pinyon) Utah juniper...

Managers require quantitative yet tractable tools that identify areas for restoration yielding effective benefits targeted wildlife species and the ecosystems they inhabit. As a contemporary example of high national significance conservation, persistence Greater Sage-grouse (Centrocercus urophasianus) in Great Basin is compromised by strongly interacting stressors conifer expansion, annual grass invasion, more frequent wildfires occurring sagebrush ecosystems. Associated treatments to...

We tested whether extracting lipids reduced confounding variation in δ 13 C and 15 N values by analyzing paired lipid-extracted (LE) non-lipid-extracted (NLE) samples of bald eagle ( Haliaeetus leucocephalus (L., 1766)) whole eggs, muscle tissue from nine seabird one terrestrial bird species, four marine fish blue mussels Mytilus edulis L., 1758) collected the Aleutian archipelago, Alaska. Lipid extraction significantly increased an average 2.0‰ 0.8‰ avian muscle, 0.2‰ 0.6‰ mussels. Lower...

Consideration of ecological scale is fundamental to understanding and managing avian population growth decline. Empirically driven models for dynamics demographic processes across multiple spatial scales can be powerful tools help guide conservation actions. Integrated (IPMs) provide a framework better parameter estimation by unifying sources data (e.g., count data). Hierarchical structure within such that include random effects allow varying degrees sharing different spatiotemporal scales....

Abstract Reliable demographic estimates hinge on the assumption that marking animals does not alter their behavior, reproduction, or survival. Violations can bias inference and are especially egregious for species of high conservation concern. Global positioning system (GPS) devices represent a recent technological advancement has contributed greatly to avian ecological studies compared with traditionally used very frequency (VHF) radio transmitters, but may affect rates differently than VHF...

Wildfires change plant community structure and impact wildlife habitat population dynamics. Recent wildfire‐induced losses of big sagebrush ( Artemisia tridentata ) in North American shrublands are outpacing natural recovery leading to substantial for sagebrush‐obligate species such as greater sage‐grouse. Managers considering restoration strategies that include planting container‐grown improve establishment within areas using more conventional seeding methods. Although it is thought...

Imperiled sagebrush (Artemisia spp.) ecosystems of western North America are experiencing unprecedented conservation planning efforts. Advances in decision-support tools operationalize concepts ecosystem resilience by quantitatively linking spatially explicit variation soil and plant processes to outcomes biotic abiotic disturbances. However, failure consider higher trophic-level fauna concern these can hinder efforts owing spatiotemporal lags between slower reorganization following...

A fundamental goal of population ecologists is to identify drivers responsible for temporal variation in abundance. Understanding whether associated with environmental stochasticity or anthropogenic disturbances, which are more amenable management action, crucial yet difficult achieve. Here, we present a hierarchical monitoring framework that models rates change abundance from spatially structured populations and identifies when local declines fall out synchrony trends at larger spatial...

Few studies of sexual segregation in ruminants have tested widely invoked mechanisms mixed-sex groups. In a sexually segregated population Roosevelt elk (Cervus elaphus roosevelti), we examined if adult males had reduced intake forage when groups and intersexual differences aggression caused females to avoid males. Based on mechanistic model intake, animals with lower instantaneous feed should higher cropping rates. Focal animal sampling indicated that summer winter similar rates groups,...

Abstract Defining boundaries of species' habitat across broad spatial scales is often necessary for management decisions, and yet challenging species that demonstrate differential variation in seasonal use. Spatially explicit indices incorporate temporal shifts selection can help overcome such challenges, especially high conservation concern. Greater sage‐grouse Centrocercus urophasianus (hereafter, sage‐grouse), a sagebrush obligate inhabiting the American West, represents an important case...

Abstract Interactions between large herbivores and their food supply are central to the study of population dynamics. We assessed temporal spatial patterns in meadow plant biomass over a 23‐year period for complexes that were spatially linked three distinct populations Roosevelt elk ( Cervus elaphus roosevelti ) northwestern California. Our objectives determine whether community exhibited tolerant or resistant response when growth became irruptive. Plant inhabited by was measured using...

We collected 136 fresh and unhatched eggs from bald eagle (Haliaeetus leucocephalus) nests assessed productivity on eight islands in the Aleutian archipelago, 2000 to 2002. Egg contents were analyzed for a broad spectrum of organochlorine (OC) contaminants, mercury (Hg), stable isotopes carbon (delta13C) nitrogen (delta15N). Concentrations polychlorinated biphenyls (SigmaPCBs), p,p'-dichlorodiphenyldichloroethylene (DDE), Hg elevated throughout but patterns distribution differed among...

First posted September 10, 2015 For additional information, contact: Director, Western Ecological Research CenterU.S. Geological Survey3020 State University Drive EastSacramento, California 95819http://werc.usgs.gov/ Greater sage-grouse (Centrocercus urophasianus; hereinafter, sage-grouse) are a sagebrush obligate species that has declined concomitantly with the loss and fragmentation of ecosystems across most its geographical range. The currently is listed as candidate for federal...

Abstract Seaducks may be affected by harmful levels of polycyclic aromatic hydrocarbons (PAHs) at seaports near the Arctic. As an indicator exposure to PAHs, we measured hepatic enzyme 7‐ethoxyresorufin‐ O ‐deethylase activity (EROD) determine cytochrome P4501A induction in Steller's eiders ( Polysticta stelleri ) and Harlequin ducks Histronicus histronicus from Unalaska, Popof, Unga Islands (AK, USA) 2002 2003. We PAHs organic contaminants seaduck prey samples polychlorinated biphenyl...

Unprecedented conservation efforts for sagebrush (Artemisia spp.) ecosystems across the western United States have been catalyzed by risks from escalated wildfire activity that reduces habitat sagebrush-obligate species such as Greater Sage-Grouse (Centrocercus urophasianus). However, post-fire restoration is challenged spatial variation in ecosystem processes influencing resilience to disturbance and resistance non-native invasive species, temporal lags between slower recovery faster...