Grizzlies, glaciers and bumble bees: a year at a USGS Rocky Mountain lab

The U.S. Geological Survey's Northern Rocky Mountain Science Center studies the wildlife and landscapes of the West — grizzlies and trout, glaciers and bumble bees, deer disease and wind turbines. Its report on fiscal year 2023 is a tour of what federal field science looks like when it is built to answer managers' questions.

Bears

Grizzlies. The centre leads the Interagency Grizzly Bear Study Team, which has monitored grizzlies in the Greater Yellowstone Ecosystem for 50 years as of 2023 — and reached that milestone at a turning point. Wyoming petitioned in 2022 to delist the Yellowstone grizzly population; the Fish and Wildlife Service is updating its species status assessment; and federal, state and Tribal partners are revising the 2016 Conservation Strategy. The team responded by combining its count, survival and reproduction data into better estimates of population size and vital rates, and finished a study on what drives the bears' body condition, which weighs heavily in policy.

Grizzlies in the Greater Yellowstone Ecosystem. USGS photograph

Louisiana black bears. Listed as threatened in 1992 and delisted in 2016, this southeastern subspecies has been monitored by the centre ever since. Its final post-delisting report, delivered in 2023, drew on 14 years of capture–recapture data to estimate abundance, growth, female survival and recruitment.

Fish, bees and frogs

Native trout. Westslope, Yellowstone and Lahontan cutthroat trout and bull trout are threatened by climate change, invasive species and habitat change. The centre is assessing how vulnerable westslope cutthroat and federally threatened bull trout are across the Rockies; tracing invading lake trout, a threat to bull trout, with geochemical signatures in water and in fish ear bones (otoliths); and combining field surveys, GIS and remote sensing to assess threatened Lahontan cutthroat in the Great Basin.

A federally threatened bull trout. U.S. Fish and Wildlife Service photograph

Trout and drought. With money from NOAA's National Integrated Drought Information System, the centre began building a drought early-warning system for Montana's trout: forecasts of trout abundance from drought risk, 3–6 months and 1–2 years ahead, and a way to test how different managed streamflows affect the fish.

Western bumble bees. Once common, now a candidate for Endangered Species Act listing, the western bumble bee is the subject of a Fish and Wildlife Service status assessment that the centre supports by studying how climate and pesticides affect it — and by developing ways to survey whole pollinator communities without putting this one at risk.

Amphibians. With other USGS centres, scientists studied invasive American bullfrogs and their diseases in the Southwest, and validated a nonlethal test for methylmercury in amphibians across 11 states and 14 species, some threatened or endangered.

Tricolored bats. Once common across the East and Midwest, now proposed as endangered after white-nose syndrome, the tricolored bat got a combined analysis of acoustic, capture and winter-roost data that could produce its range map.

Deer, elk and disease

Chronic wasting disease kills deer, elk and moose, has spread across North America for at least 20 years, and has no vaccine or treatment. Two projects:

• For the Forest Service, a structured decision analysis of whether to let Wyoming keep feeding elk in winter on the Bridger-Teton National Forest — modelling four options' effects on wildlife and the regional economy.
• On the Wind River Reservation in Wyoming, with the Northern Prairie Wildlife Research Center, finding transmission hotspots among mule and white-tailed deer from movement, density and disease data — and whether migrating or resident mule deer drive the high infection rate.

Mule deer. Bureau of Land Management photograph

Climate, snow and ice

• Snow for Tribal water planning. With the Wyoming-Montana Water Science Center, the centre built a high-resolution snow model for the Crown of the Continent and held workshops with water managers from the Blackfeet Nation and the Confederated Salish and Kootenai Tribes and faculty from Blackfeet Community College and Salish Kootenai College. A student in Salish Kootenai College's first natural resource management master's programme is using the model; the Tribes plan to build water strategies on that research.
• Glaciers. The USGS Benchmark Glacier Project keeps North America's longest continuous field record of glacier mass balance. In 2023 the centre and two Alaska USGS centres built a data platform giving Park Service and Forest Service partners glacier thickness, elevation change and motion data.
• Adapting to change. A framework to build species' adaptive capacity — their ability to cope through genes, behaviour or moving — into vulnerability assessments, set within the Resist–Accept–Direct approach: hold an ecosystem as it is, let it change, or steer it.

Energy and invasions

• Wind and wildlife. New work with the Department of Energy, NOAA and industry on birds and bats at offshore wind sites in the Great Lakes and Gulf of Mexico, including a test of whether painting one turbine blade black cuts bird deaths. In September 2023 the team trialled an offshore biological radar from a NOAA ship.
• Pronghorn. A study of how wind farms and their construction change the migrations of female pronghorn in Wyoming — animals whose movements are larger and less predictable than any other North American hoofed mammal's.
• READI-Net. A national USGS project the centre leads, using environmental DNA to catch aquatic invaders early. In 2023 it developed an autosampler that can take more than 140 samples, field-tested another design, and worked on high-throughput methods.

A READI-Net autosampler on a Montana creek. USGS photograph

The NOAA ship used to test the offshore radar in the Gulf of Mexico. USGS photograph

Sources

Written from U.S. Geological Survey Northern Rocky Mountain Science Center Science Highlights for Fiscal Year 2023, USGS Fact Sheet 2024–3012, a work of the United States government in the public domain.