Software

This code release fits a Bayesian logistic regression model to predict the probability that stream segments flowing through National Park lands in Alaska are considered navigable, based on slope (drop in elevation / segment length) and Strahler stream order, an ordinal metric with values ranging from 1-6. The model uses existing navigability determinations for a subset of stream segments...

This project compared methods for estimating large scale patterns of animal resource selection and species distribution to demonstrate the benefits of marginalized space-time point process models.

This script simulates data under an example scenario and applies a model to the simulated dataset to estimate trend, thus evaluating the power to detect the trend. The study was designed to evaluate various scenarios (sampling designs, as well as biological parameters that differ between the two study lagoons).

This is nimble model code for a hierarchical Bayesian analysis to estimate walrus herd density at multiple sites, where some surveys entailed counting walruses in a sample of grid cells overlain on the surveyed herd on shore; whereas, other surveys were censuses (complete counts.) The model code also predicts herd densities for new surveys taken at existing sites and a new site.

Code for R Shiny application to facilitate visualizing and subsetting the North Pacific Pelagic Seabird Database (NPPSD) using an interactive leaflet map. Database records can be filtered by higher taxonomy (bird vs. mammal observations), family, species, primary investigator, survey type date, and location. Users have the option to automatically zoom to the selected subset, or to zoom...

This pyQGIS script and adjoining QGIS layout templates and style specification generate maps from satellite imagery and any derived geospatial outline data that are inventoried and cross-referenced in a tabular inventory file. The maps are intended for mangers, decision makers, and researchers to support real-time decision making and to provide a graphical record that may be publicly...

These Python scripts enable download of Sentinel 1 & 2 imagery for multiple study sites by accessing the Copernicus Data Base Ecosystem.

Polar bears (Ursus maritimus) of the Southern Beaufort Sea (SBS) historically spent nearly the entire year on the sea ice but are increasingly using land habitat as sea ice becomes less available seasonally due to climate warming. The U.S. Geological Survey, Alaska Science Center maintains a research program on the SBS polar bear subpopulation and one important research question is...

This code release contains R and JAGS code for estimating average eelgrass biomass at two lagoons (Izembek and Kinzarof) within the Izembek National Wildlife Refuge, Alaska, using data from point count surveys conducted by National Wildlife Refuge and U.S. Geological Survey (USGS) personnel. Biomass is estimated using a gamma hurdle model which models the probability of occurrence and...

This project aimed to develop methods to estimate spatially explicit survival of wildlife from telemetry data.

This code repo contains three scripts used in the associated manuscript to run the analyses (01_model_prob_flight.r; 02_model_altitude_selection.r) and the simulation used to make predictions (03_simulate_prob_fly_per_altitude.r). The analysis serves to evaluate conditions that affect 1) whether geese are in flight vs. resting on the water, 2) what altitude is selected by flying geese...

This project aimed to find connections between step-selection functions (SSFs) and partial differential equation models of animal movement and, in doing so, improve the flexibility of SSFs. Please see the associated manuscript cited above for further details.