Biology subjects

Lesmeister, D. B.

Publications and source records attributed to Lesmeister, D. B..

7 recordsLinked to original sources

bioRxiv2026

Using spatial prioritization to navigate current and future tradeoffs when controlling invaders

Controlling invasive species is a global conservation priority but is typically resource-limited, necessitating strategies to optimize control. Spatial prioritization methods can improve the efficiency of invader control by quantifying the benefits, costs, and risks of alternative intervention strategies. Yet prioritization designs are sensitive to the distinction between protecting native populations that are currently sympatric with invaders versus safeguarding presently allopatric native populations by preventing invader expansion. Gaining a better understanding of this distinction stands to improve our ability to prioritize the management of invaders whose distributions--and thus impacts on native species--are dynamic. We asked how prioritization designs addressing current versus future invader threats affected tradeoffs among focal species protection, biodiversity conservation, disturbance risk, and overlap with existing conservation infrastructure. As a case study, we spatially prioritized population control of invasive barred owls (Strix varia) in the northwestern US. We found that distinguishing between current versus future threats posed by barred owls to the native spotted owl (S. occidentalis) strongly mediated whether invader control stood to benefit native at-risk animal communities. Furthermore, this distinction also affected the degree to which population control would overlap with fire risk and federally protected forests, both of which plausibly affect the viability and success of conservation action. These results thus illustrate that deciding to prioritize the control of invaders based on their current versus future impacts on native species can dramatically affect the distribution and characteristics of high-priority areas for management. Our findings also directly inform control of barred owls in the northwestern US: we found that prioritizing future threats to spotted owls could protect at-risk amphibian communities from novel barred owl predation, but that high fire risk and minimal protected forest may complicate implementation. Thus, in both our system and more broadly, spatial prioritization methods are an important tool for quantitative, reproducible, and successful invader control.

ecology↗

bioRxiv2026

Passive Acoustic Monitoring within the Northwest Forest Plan Area: 2025 Annual Report

The Northwest Forest Plan (NWFP) Passive Acoustic Monitoring (PAM) program is a large-scale interagency biodiversity monitoring framework designed to assess the status and trends of northern spotted owls (Strix occidentalis caurina), barred owls (Strix varia), marbled murrelets (Brachyramphus marmoratus), and broader forest biodiversity across federally administered lands in the Pacific Northwest. In 2025, we deployed autonomous recording units at 2,095 sampling stations within 532 5-km2 hexagons randomly selected across approximately 24 million acres of federal forest lands in Washington, Oregon, and California. These deployments generated 1.37 million hours of acoustic recordings that we processed using the convolutional neural network PNW-Cnet v5 for automated species identification and subsequent human validation of focal species detections. Northern spotted owls were detected in 28% of sampled hexagons range-wide, including 16% in Washington, 25% in Oregon, and 60% in California. Occupancy patterns remained consistent compared to previous years, with higher occupancy concentrated in southern portions of the geographic range and continued low occupancy across much of the Washington Cascades and Oregon Coast Range. Barred owls were detected in 86% of sampled hexagons and remained broadly distributed throughout most of the NWFP area. Marbled murrelets were detected in 50% of reviewed hexagons within NWFP marbled murrelet management zones, with highest occupancy occurring in coastal forests of Oregon and Washington. The 2025 field season occurred under substantial operational constraints that reduced sampling effort by approximately half relative to 2023 and 2024 because of staffing limitations affecting participating federal agencies. Despite these reductions, the NWFP-PAM framework continued to provide broad-scale, spatially representative ecological information across the NWFP area. Results highlight the growing importance of passive acoustic monitoring and machine learning approaches for long-term biodiversity monitoring under changing environmental and operational conditions.

ecology↗

bioRxiv2025

Passive Acoustic Monitoring within the Northwest Forest Plan Area: 2024 Annual Report

Passive acoustic monitoring (PAM) has become the primary framework for assessing the status, distribution, and habitat associations of forest-dependent wildlife under the Northwest Forest Plan (NWFP). In 2024, the NWFP PAM program continued to operate as a fully integrated, range-wide monitoring network, building on deployments initiated in 2018 and now conducting surveys across approximately 24 million acres of federal land. Using a randomized 2+20% sampling design, more than 4,000 autonomous recording units generated over 2 million hours of acoustic data analyzed with convolutional neural networks, enabling statistically rigorous inference at regional and range-wide scales. This report summarizes 2024 field efforts and analytical advancements in the context of recent peer-reviewed and in-progress studies. Updated analyses confirm persistent, low occupancy of northern spotted owls (Strix occidentalis caurina), with detections concentrated in the Klamath Mountains and southern Cascades, consistent with long-term demographic declines. Range-wide models of barred owl (Strix varia) landscape use continue to show high occupancy across much of the NWFP area, reinforcing competitive displacement as the dominant driver of spotted owl range contraction. The PAM network also advanced monitoring of marbled murrelets (Brachyramphus marmoratus), with 2024 results supporting PAM as a cost-efficient alternative to traditional audio-visual surveys for assessing inland nesting habitat use in coastal forests. Beyond focal species, the program increasingly supports multi-taxa biodiversity monitoring through bioacoustic bycatch and soundscape analyses, linking species occurrence, habitat condition, and disturbance dynamics. Collectively, 2024 results demonstrate that PAM has reached operational maturity as the cornerstone of Phase II NWFP effectiveness monitoring. Sustaining adequate sampling effort and field capacity remains a challenge but essential, as reduced deployment intensity would increase uncertainty and weaken inference. Continued investment in PAM infrastructure and expertise is critical for informing adaptive management, supporting sustainable timber harvest, and evaluating ecosystem resilience under changing disturbance regimes.

ecology↗

bioRxiv2025

Passive Acoustic Monitoring within the Northwest Forest Plan Area: 2023 Annual Report

Here we document progress in implementing large-scale passive acoustic monitoring across the Northwest Forest Plan area to track population trends of northern spotted owls (Strix occidentalis caurina), barred owls (S. varia), marbled murrelets (Brachyramphus marmoratus), and a broad array of forest-adapted wildlife. In 2023, we deployed 4,012 autonomous recording units across 1,009 randomly selected 5-km{superscript 2} hexagons, generating nearly 2.2 million hours of recordings, representing approximately 1 petabyte of acoustic data. These data were processed with PNW-Cnet v5, the latest version of our convolutional neural network model, trained on 135 sound classes representing over 80 species and environmental sounds. Model performance demonstrated high precision for focal species and many additional taxa, substantially reducing manual review effort while enabling broad-scale biodiversity assessments. Results confirmed northern spotted owl detections in all 20% sample areas, with occupancy varying geographically and declining notably in the Tyee study area. Barred owls were widely detected, with the highest prevalence in Oregon and Washington and comparatively lower occupancy in California. Marbled murrelets were consistently detected in coastal areas, particularly the Olympic Peninsula and Oregon Coast Range. Beyond these focal species, PAM and PNW-Cnet generated robust datasets for a wide range of birds, mammals, and disturbance indicators, underscoring the value of random-site, multi-species monitoring. The 2023 field season marked the first full implementation of the 2% + 20% NWFP sampling design, expanding monitoring coverage while strengthening collaborations with federal and state partners. These efforts provide the foundation for long-term, cost-effective wildlife monitoring and inform conservation strategies in dynamic forest ecosystems.

ecology↗

bioRxiv2022

Western spotted skunks provide important food web linkages in forest of the Pacific Northwest

There are increasing concerns about the decreasing population trends of small mammalian carnivores around the world. With limited knowledge about their ecology and natural history, small mammal conservation and management remains difficult. To address one of these deficiencies for western spotted skunks (Spilogale gracilis), we investigated their diet in the Oregon Cascades of the Pacific Northwest during 2017 - 2019. We collected 130 spotted skunk scats opportunistically and with detection dog teams and identified prey items using DNA metabarcoding and mechanical sorting. Western spotted skunk diet consisted of invertebrates such as wasps, millipedes, and gastropods, vertebrates such as small mammals, amphibians, and birds, and plants such as Gaultheria, Rubus, and Vaccinium. Diet also consisted of items such as black-tailed deer that were likely scavenged. Comparison in diet by season revealed that spotted skunks consumed more insects during the dry season (June - August) and marginally more mammals during the wet season (September - May). We observed similar diet in areas with no record of human disturbance and areas with a history of logging. Western spotted skunks provide important food web linkages between aquatic, terrestrial, and arboreal systems by facilitating energy and nutrient transfer, and serve important functional roles of seed dispersal and scavenging. Through prey-switching, western spotted skunks may dampen the effects of irruptions of prey, such as wasps during dry springs and summers, which could then provide ecosystem resilience to environmental change.

ecology↗

bioRxiv2021

Emigration Effects on Estimates of Age- and Sex-specific Survival of Small Mammals

O_LIAge- and sex-specific survival estimates are crucial to understanding important life-history characteristics and variation in these estimates can be a key driver of population dynamics. When estimating survival using Cormack-Jolly-Seber (CJS) models and capture-recapture data, emigration is typically assumed to have a negligible effect on estimates such that apparent survival is indistinguishable from true survival. Consequently, especially for populations or age classes with high dispersal rates, apparent survival estimates are often biased low and temporal patterns in survival might be masked when site fidelity varies temporally. C_LIO_LIWe used 9 years of annual mark-recapture data to estimate age-, sex-, and time-specific apparent survival of Humboldts flying squirrels (Glaucomys oregonensis) and Townsends chipmunks (Neotamias townsendii). For Humboldts flying squirrels, these estimates support a small body of research investigating potential variation of survival among age and sex classes, but age- and sex-specific survival has not been evaluated for Townsends chipmunks. We also quantified the effects of age- and sex-specific emigration on confounded estimates of apparent survival. C_LIO_LIOur estimates of juvenile flying squirrel survival were high relative to other small mammal species and estimates for both species were variable among years. We found survival differed moderately among age and sex classes for Humboldts flying squirrels, but little among age and sex classes for Townsends chipmunks, and that the degree to which emigration confounded apparent survival estimates varied substantially among years. Without correcting for emigration, apparent survival estimates were lower and temporal variation was obscured, particularly for male Humboldts flying squirrels and female Townsends chipmunks. C_LIO_LIOur results demonstrate that emigration can influence commonly used estimates of apparent survival. Unadjusted estimates confounded the interpretation of differences in survival between age and sex classes and masked potential temporal patterns in survival because the magnitude of adjustment varied among years. We conclude that apparent survival estimators are robust during some time periods; however, when emigration rates vary in time the effects of emigration should be carefully considered and accounted for, especially in comparative studies and those with policy and conservation implications. C_LI

ecology↗

bioRxiv2020

A Convolutional Neural Network and R-Shiny App for Automated Identification and Classification of Animal Sounds

The use of passive acoustic monitoring in wildlife ecology has increased dramatically in recent years as researchers take advantage of improvements in automated recording units and associated technologies. These technologies have allowed researchers to collect large quantities of acoustic data which must then be processed to extract meaningful information, e.g. target species detections. A persistent issue in acoustic monitoring is the challenge of processing these data most efficiently to automate the detection of species of interest, and deep learning has emerged as a powerful approach to achieve these objectives. Here we report on the development and use of a deep convolutional neural network for the automated detection of 14 forest-adapted species by classifying spectrogram images generated from short audio clips. The neural network has improved performance compared to models previously developed for some of the target classes. Our neural network performed well for most species and at least satisfactory for others. To improve portability and usability by field biologists, we developed a graphical interface for the neural network that can be run through RStudio using the Shiny package, creating a highly portable solution to efficiently process audio data closer to the point of collection and with minimal delays using consumer-grade computers.

bioinformatics↗