Treesearch

Wild foods are critical to the food security of billions of people worldwide, yet the ecological mechanisms that promote wild food system stability remain poorly understood. Within complex food webs, ecological theory predicts that nonhuman consumers can maintain more stable consumption rates by foraging on multiple resources that vary asynchronously in their availability across space and time. These so-called portfolio effects may also sustain more stable harvest rates by humans in wild food systems. We analyzed wild food harvest patterns for 46 isolated rural communities in southern...

The marbled murrelet (Brachyramphus marmoratus) is a seabird of conservation concern that nests in late-successional, old-growth forests in Oregon, Washington, and California, USA. Traditional audio-visual surveys have been the standard method for detecting murrelets in forests. Given that murrelets can be extremely cryptic in forest environments, audio-visual surveys are difficult, time consuming, and expensive to conduct. Passive acoustic monitoring (PAM) may be a useful and cost-effective alternative. Using a paired murrelet survey design, we compared detection probabilities across 88...

Many ectothermic vertebrates have predictable seasonal activity and habitat use patterns, but variable patterns at fine temporal scales (e.g., minutes to days) that are likely influenced by thermoregulatory demands on behavior. Wood turtles (Glyptemys insculpta) are freshwater turtles known to use terrestrial environments during their active period. However, little research has been conducted to quantify the influence of environmental factors on diel habitat use patterns. We used fine-resolution global positioning system (GPS) tracking and temperature data to quantify wood turtle aquatic-te...

Invasive predators can reshape native predator assemblages, triggering cascading changes in broader wildlife communities. In western North America, the barred owl (Strix varia) is an invasive apex predator with well-documented negative impacts on congeneric northern spotted owls (Strix occidentalis caurina), but impacts on other native forest owls are poorly understood. We coupled a large-scale removal experiment with a passive acoustic monitoring network to quantify species-specific and community-level responses of a five-species assemblage of native forest owls to the lethal removal of...

The body size of aquatic vertebrates is declining across populations and ecosystems worldwide owing to warmer water temperature and changing streamflow. In freshwaters, the effects of stream network position and density-dependent factors on body size are less understood. We used an extensive dataset spanning 41 stream sites over 7 years to evaluate how density-dependent and density-independent factors influence the size of two top predators in small watersheds, Coastal Cutthroat Trout Oncorhynchus clarkii clarkii and Coastal Giant Salamanders Dicamptodon tenebrosus. We tested three...

Aquatic invasive species can devastate native biodiversity and human water infrastructure. Effective eradication relies on early detection. However, commonly used visual surveys are ineffective for detection of small populations of submerged invasive species in large water bodies. Here, we explored detection of invasive aquatic plants, animals (vertebrate and invertebrate), and pathogens using 10 environmental DNA (eDNA) water sampling events every two weeks between June and October, 2018, informing ideal sampling times for long-term early-detection monitoring. The highest number of...

Background: Drought, human disturbance, and invasive species are reshaping disturbance regimes and increasing the scale, severity, and frequency of wildfire in many ecosystems around the globe, including the sagebrush steppe of western North America. Recent studies suggested greater sage-grouse (Centrocercus urophasianus) adhere to strong site fidelity in the aftermath of wildfire, remaining inside fire perimeters for nesting and brood rearing despite negative consequences for survival and reproduction. Sage-grouse in Idaho exhibited context-dependent changes to space use after a large,...

Large-scale hydrologic models are increasingly being developed for operational use in the forecasting and planning of water resources. However, the predictive strength of such models depends on how well they resolve various functions of catchment hydrology, which are influenced by gradients in climate, topography, soils, and land use. Most assessments of hydrologic model uncertainty have been limited to traditional statistical methods. Here, we present a proof-of-concept approach that uses interpretable machine learning techniques to provide post hoc assessment of model sensitivity and...

Many territorial species use vocalizations as a primary form of territory defense, and the areas actively defended do not necessarily correspond with an individual's home range. As passive acoustic monitoring becomes a primary population assessment method for soniferous species, often in combination with occupancy modeling, effective conservation will require more detailed information on species-specific space use to refine interpretation. Northern spotted owls (Strix occidentalis caurina) actively vocalize during the breeding season, but interpreting acoustic data is complicated by...

The Spotted Turtle (Clemmys guttata) is a small freshwater turtle that is currently under review for federal listing under the U.S. Endangered Species Act. Recent distributional models suggest that Spotted Turtles potentially occur in the eastern panhandle, northcentral, and northern panhandle regions of West Virginia, with previous survey efforts documenting the species at three wetlands in the eastern panhandle. We sampled 62 sites across 41 unique wetlands in West Virginia to assess the contemporary region-scale distribution and identify occupied wetlands. We used the results of these...