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The CRU program remains very productive and maintains a bright future. One of the things contributing to that bright future is a $5.6 million increase in our most recent Congressional appropriations. This amount will help us meet longstanding programmatic needs, such as filling all the vacancies in our scientific workforce and providing much-needed upgrades to our research equipment.

CRU Science
Filter Total Items: 27
Date published: September 16, 2019
Status: Active

App Allows Citizen Scientists to Contribute to Monarch Butterfly Research

Researchers with the U.S. Geological Survey Maine Cooperative Fish and Wildlife Research Unit (Maine CRU) have developed a model that predicts areas that have a high suitability for monarch butterflies for roosting during their fall migration to Mexico. 

Date published: August 12, 2019
Status: Active

Scientists Without Borders - Range-Wide Conservation for a Freshwater Mussel at Risk

Despite repeatedly being referenced as uncharismatic, few organisms can bring together 21 different agencies, drawing on collaborations from 14 states – but that is just what is happening with a freshwater mussel in the Northeast.

Date published: July 31, 2019
Status: Active

USGS Alaska Science Center Wildlife Tracking Data Collection

Understanding the short- and long-distance movements of wildlife is critical for a wide variety of ecological research questions and management decisions. Since the mid-1980s, the USGS Alaska Science Center has used information from telemetry devices on wildlife species to determine locations of animals throughout their annual cycles, understand patterns of habitat use, quantify time spent on...

The Cooperative Research Units Program conducts research on a wide range of disciplines related to fish, wildlife, and natural resource management. Our 40 Units collectively conduct research on virtually every type of North American ecological community. 

Data and Tools Technical Publications
Filter Total Items: 104
Date published: November 9, 2020

Migration Routes of Mule Deer in the Ryegrass Population in Wyoming

The Ryegrass mule deer population is part of the larger Sublette herd that winters in the northwest portion of the Green River Basin, west of the Green River and north of Cottonwood Creek (fig. 34). In severe winters, these deer may travel southeast to The Mesa, Ross Ridge, or Reardon Draw areas. The Ryegrass region supports approximately 1,500 to 2,000 deer that migrate northwest

Date published: November 9, 2020

Migration corridors of mule deer in the Pequop Mountains, Nevada

The Area 7 mule deer population is one of the state’s largest deer herds with an estimated population of about 11,000 in 2019. This deer herd is highly important to Nevada from an economic and ecological perspective. It’s one of the longest distance deer migrations in the state of Nevada with some animals known to migrate over 120 miles during a single migration. A subset of th

Date published: November 9, 2020

Migration Routes of Mule Deer in the Upper Shoshone Herd in Wyoming

Mule deer within the Upper Shoshone herd make a number of significant, long-distance migrations west into the core of the Greater Yellowstone Ecosystem. The longest is a 133-mile (214-km) migration that originates at the mouth of the South Fork of the Shoshone River near Buffalo Bill Reservoir and ends at Jenny Lake in Grand Teton National Park. Deer in the Upper Shoshone herd winter in the...

Date published: November 9, 2020

Winter Range of Elk in the Interstate 17 Herd in Arizona

The Interstate 17 (I-17) elk herd primarily resides in Arizona’s GMU 6A and 11M south of Flagstaff. The population estimate for elk in GMU 6A was 6,500 in 2019. Their summer range consists of gentle topography with ponderosa pine forest and interspersed riparian-meadow habitat. Annually, the I-17 elk herd migrates an average of 24 miles to lower-elevation winter range dominated by

Date published: November 9, 2020

Migration Corridors of Mule Deer in the San Francisco Peaks Herd in Arizona

In 2008, 13 mule deer were GPS collared near the South Rim of the Grand Canyon to understand the impact of Arizona’s State Route 64 on mule deer movement. Unexpectedly, 4 individuals migrated over 50 miles to summer range near the San Francisco Peaks, north of Flagstaff, containing alpine, subalpine, and ponderosa pine habitats. The GPS collars dropped in 2009, but questions

Date published: November 9, 2020

Migration Routes of Mule Deer in Clarks Fork Herd in Wyoming

Mule deer within the Clarks Fork herd make a number of significant westward long-distance migrations. These migrations originate north of Cody, near Heart Mountain and along the foothills of Absaroka Front. There, deer winter in the lower elevation sagebrush valleys, and in spring an estimated 2,700 deer head west into the high elevation mountain valleys of the Absaroka Range and Yellowst

Date published: November 9, 2020

Migration routes of mule deer in the Izzenhood herd, Nevada

Mule deer in the Izzenhood herd are part of a larger population known in Nevada as the “Area 6” mule deer population. They primarily reside on winter ranges in the Izzenhood Basin and upper Rock Creek drainages in western Elko County and northern Lander County. From their winter range, mule deer in this sub population migrate approximately 70 miles to summer ranges in the north

Date published: November 9, 2020

Migration Routes of Elk in Cody Herd in Wyoming

The Cody elk herd migrates across rugged country on the eastern side of the Absaroka Mountains near Cody, WY. This large herd of 6,000-7,000 animals winters in foothill habitat to the south and west of Cody. There are three core winter areas, namely the valleys formed by the North and South Fork of the Shoshone River and the headwaters of the Greybull River north to Meeteetse creek. In sp

Date published: November 9, 2020

Stopovers of mule deer in the Sublette Herd, Wyoming

The Platte Valley Herd Corridor was designated by the Wyoming Game and Fish Department in 2018 (fig. 30). The Platte Valley herd contains approximately 11,000 mule deer. The corridor is based on two wintering populations, including a south segment from Saratoga, Wyoming, to the Colorado State line, and a north segment from Saratoga to the Dana Ridge area north of I-80. Winter ranges

Date published: November 9, 2020

Migration Routes of Mule Deer in the Dubois Herd in Wyoming

Mule deer within the Dubois herd make several long-distance migrations into the heart of the Greater Yellowstone Ecosystem (fig. 26). These migrations originate from winter range in the warm, protected sagebrush valley surrounding Dubois, Wyoming, and extend to the southeast on the Wind River Reservation. Each spring, an estimated 6,000–7,000 deer leave this valley and the

Date published: November 9, 2020

Migration Routes of Elk in Fossil Buttes Population in Wyoming

The Fossil Butte (hereafter referred to as the Monument in this section of the report) elk population winters in the southern Wyoming Range between Fossil Butte National Monument and Cokeville (fig. 45). During spring, they migrate north short (11 mi [18 km]) to medium (74 mi [119 km]) distances. The segment of the elk population that winters near the Monument migrates i

Date published: November 9, 2020

Migration Routes of Mule Deer in Atlantic Rim North Population in Wyoming

Mule deer in the Atlantic Rim North population are part of the Baggs herd unit that is managed for approximately 19,000 animals. These mule deer winter in the pinyon-juniper and sagebrush badlands near Dad, Wyoming and migrate north and east 10–35 mi (16–56 km) to various summer ranges (fig. 22). Many of these deer must navigate coal-bed methane development that is sit

Filter Total Items: 2,921
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Year Published: 2021

Making Recursive Bayesian inference accessible

Bayesian models provide recursive inference naturally because they can formally reconcile new data and existing scientific information. However, popular use of Bayesian methods often avoids priors that are based on exact posterior distributions resulting from former studies. Two existing Recursive Bayesian methods are: Prior- and Proposal-...

Hooten, Mevin; Johnson, Devin S.; Brost, Brian M.

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Year Published: 2021

Selenium, mercury, and their molar ratios in sportfishes from drinking water reservoirs

Mercury (Hg) bioaccumulates in aquatic ecosystems and may pose a risk to humans who consume fish. Selenium (Se) has the ability to reduce Hg toxicity, but the current guidance for human consumption of fish is based on Hg concentration alone. The purpose of the present study was to examine the relationship between Se and Hg in freshwater sportfish...

Johnson, Tara K. B.; LePrevost, C. E.; Kwak, Thomas J.; Cope, W. G.

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Year Published: 2020

Estimating the invasion extent of Asian swamp eel (Monopterus: Synbranchidae) in an altered river of the south-eastern United States

The first reported invasion of Asian swamp eels (Monopterus albus, ASE) in the continental United States was in the state of Georgia in 1994. This population was first discovered within several ponds on a private nature centre, but the ponds drained via an outflow pipe into marsh habitats along the Chattahoochee River. Our objective was to...

Johnson, J.R.; Taylor, A.T.; Long, James M.

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Year Published: 2020

Comparing native bee communities on reconstructed and remnant prairie in Missouri

The tallgrass prairie of North America is an imperiled ecosystem that has been the subject of considerable restoration effort and research in the past two decades. While native prairie plant species are purposely introduced during restoration, prairie invertebrates, including native bees (Anthophila), are not, and must colonize from surrounding...

LaRose, J. P.; Webb, Elisabeth B.; Finke, D. L.

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Year Published: 2020

Deep-sea coral and sponge taxa increase demersal fish diversity and the probability of fish presence

Fishes are known to use deep-sea coral and sponge (DSCS) species as habitat, but it is uncertain whether this relationship is facultative (circumstantial and not restricted to a particular function) or obligate (necessary to sustain fish populations). To explore whether DSCS provide essential habitats for demersal fishes, we analyzed 10 years of...

Henderson, Mark J.; Huff, D.D.; Yoklavich, M.M

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Year Published: 2020

Why let the dogs out? Exploring variables associated with dog confinement and general characteristics of the free-ranging owned-dog population in a peri-urban area

Free-ranging dogs (FRDs), are a problem in several countries, with impacts on humans, domestic animals, and wildlife, although increasing evidence suggests that most FRDs are owned. Therefore, understanding dog ownership on a fine scale is critical. The main objectives of this study were to explore dog management in rural localities from central...

Astorga, Francisca; Poo-Muñoz, Daniela Alejandra; Organ, John F.; Medina-Vogel, Gonzalo

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Year Published: 2020

Temporal and spatial changes in Myotis lucifugus acoustic activity before and after white-nose syndrome on Fort Drum Army Installation, New York, USA

Changes to bat distribution and habitat associations at the local to sub-landscape scale in the post white-nose syndrome (WNS) environment have received little attention to date despite being critical information for managers. To better understand the spatial nature of bat population declines, we modelled both activity patterns and occupancy from...

Ford, W. Mark; Nocera, Tomás; Silvis, Alexander; Dobony, Christopher A.

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Year Published: 2020

Estimating response distances of lesser prairie-chickens to anthropogenic features during long-distance movements

Spatially distributed populations often rely on large-scale processes for long-term population stability. These processes are driven by individuals moving across the landscape through long-distance dispersal movements. However, as landscapes are continually altered by anthropogenic development, increased fragmentation and avoidance behavior can...

Peterson, Jacob M.; Earl, Julia E.; Fuhlendorf, Samuel D.; Elmore, Dwayne; Haukos, David A.; Tanner, Ashley M.; Carleton, Scott A.

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Year Published: 2020

Longer-lived tropical songbirds reduce breeding activity as they buffer impacts of drought

Droughts are expected to increase in frequency and severity with climate change. Population impacts of such harsh environmental events are theorized to vary with life history strategies among species. However, existing demographic models generally do not consider behavioural plasticity that may modify the impact of harsh events. Here we show that...

Martin, Thomas E.; Mouton, James C.

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Year Published: 2020

Nest predation and adult mortality relationships with post-natal metabolic rates and growth among songbird species

Metabolism is thought to mediate the connection between environmental selection pressures and a broad array of life history tradeoffs, but tests are needed. High juvenile predation correlates with fast growth, which may be achieved via fast juvenile metabolism. Fast offspring metabolism and growth can create physiological costs later in life that...

Ton, Riccardo; Mitchell, Michael S.

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Year Published: 2020

Bidirectional connectivity via fish ladders in a large Neotropical river: Response to a comment

In a recent article, we described fitting electronic tags to the fish Prochilodus lineatus to document how a fishway connected aquatic habitats downstream and upstream of a major dam. Moreover, given that tagged fish remained upstream or downstream for periods extending months and years before returning to the fishway, and that observed...

Celestino, L.F.; Sanz-Ronda, F.J.; Miranda, Leandro E.; Makrakis, M.C.; Pinheiro Dias, J.H.; Makrakis, S.

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Year Published: 2020

Adaptive management in wildlife conservation

No abstract available.

Organ, John F.; Decker, Daniel J.; Riley, Shawn J.; Mcdonald, John E.; Mahoney, Shane P.

Under the guidelines of the Cooperative Research Agreement, CRU is required to communicate with funders, cooperators, stakeholders, and the public. CRU maintains outreach pathways and participation among state, federal, university, and private researchers.

Filter Total Items: 53
Andrena spp. seemingly getting a piggyback ride from a bumblebee (Bombus spp.)
May 29, 2019

Bee landing zone

Andrena spp. seemingly getting a piggyback ride from a bumblebee (Bombus spp.). Researcher was holding the flower on private land in Macon County.

Halictus ligatus female on an oxeye daisy (Chrysanthemum leucanthemum).
May 29, 2019

Halictus ligatus female on an oxeye daisy (Chrysanthemum leucanthemum)

The center of the composite flower looks like a "landing zone" and has evolved to guide pollinators to its nectar/pollen.

Trail camera field work in Arizona
April 12, 2019

Trail camera field work in Arizona

Ongoing camera monitoring efforts in Southern Arizona to monitor wildlife for the goal of detecting endangered jaguars and ocelots have covered 20 mountain ranges, off and on, from 2012 to 2019.  Currently monitoring 12 Southern Arizona mountain ranges, this project is being conducted exclusively in the field by citizen science volunteers at the University of Arizona under

...
Trail camera field work in Arizona
April 12, 2019

Trail camera field work in Arizona

Ongoing camera monitoring efforts in Southern Arizona to monitor wildlife for the goal of detecting endangered jaguars and ocelots have covered 20 mountain ranges, off and on, from 2012 to 2019.  Currently monitoring 12 Southern Arizona mountain ranges, this project is being conducted exclusively in the field by citizen science volunteers at the University of Arizona under

...
Trail camera field work in Arizona
April 12, 2019

Trail camera field work in Arizona

Ongoing camera monitoring efforts in Southern Arizona to monitor wildlife for the goal of detecting endangered jaguars and ocelots have covered 20 mountain ranges, off and on, from 2012 to 2019.  Currently monitoring 12 Southern Arizona mountain ranges, this project is being conducted exclusively in the field by citizen science volunteers at the University of Arizona under

...
 Assessing fish habitat and population dynamics of fisheries resources at Kaloko Fishpond
July 29, 2018

Assessing fish habitat and population dynamics of fisheries resources

Throughout Hawaii, fishponds are considered by their local communities as important cultural touchstones, a source of local, sustainably produced food, and an important component to the development of community-based management for nearshore fisheries. Within Kaloko Honokōhau National Historic Park, the restoration of Kaloko Fishpond for traditional aquaculture management

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Assessing the Functional Equivalency of Hawaiian fishponds
July 29, 2018

Assessing the Functional Equivalency of Hawaiian fishponds

Hawaiian fishponds are important cultural and economic resources for native Hawaiians as they are an important component of a sophisticated, integrated food production system. However, changing demographics and systems of land ownership result in declines in the use and upkeep of Hawaiian fishponds throughout the 19th century. The cultural value of Hawaiian fishponds has

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Assessing the Functional Equivalency of Hawaiian fishponds
July 29, 2018

Assessing the Functional Equivalency of Hawaiian fishponds

Hawaiian fishponds were important cultural and economic resources for native Hawaiians as they were an important component of a sophisticated, integrated food production system. However, changing demographics and systems of land ownership resulted in a decline in the use and upkeep of Hawaiian fishponds throughout the 19th century. The cultural value of Hawaiian fishponds

...
Canada lynx
June 21, 2018

Canada Lynx

– Scientists at the USGS Massachusetts Cooperative Fish and
Wildlife Research Unit at the University of Massachusetts Amherst, in
collaboration with The Rockefeller University’s Vertebrate Genome Laboratory,
New York, are releasing to a public repository at the vertebrate lab, for use by
geneticists, conservationists and other researchers around the

...
 A Zone-tailed Hawk in flight.
May 4, 2018

Zone-tailed hawk in flight

Raptors in the Trans Pecos, Texas Cooperative Fish and Wildlife Research Unit: State-Threatened, Riparian-Obligate Raptors in the Trans Pecos:  Desert riparian systems are distinct narrow drainages that provide environmental conditions for vegetation dependent on permanent or ephemeral surface and subsurface water. This results in desert riparian zones provide important

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 Assessing the distribution and habitat needs of the least darter
April 27, 2018

Assessing the distribution and habitat needs of the least darter

Isolated populations may benefit from different conservation and management activities. The least darter is a species of conservation concern that has two isolated populations occupying parts of the Arbuckle Mountain and Ozark Highlands ecoregions. The goal of this research is to assess different environmental factors at multiple spatial scales to determine the relations

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Alligator Hatchlings
December 31, 2017

Alligator Hatchlings

Crocodilians are one of the few reptile taxa that exhibit parental care. In alligators, following nest construction, females stay nearby in a guard hole, and are known to defend their nests against predators or other intruders. At the end of the 60-day incubation period, alligator hatchlings will vocalize from within the egg, to signal to the mother that they are ready to

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Filter Total Items: 28
Date published: January 23, 2015

Culprit Identified in Decline of Endangered Missouri River Pallid Sturgeon

BOZEMAN – Pallid sturgeon come from a genetic line that has lived on this planet for tens of millions of years; yet it has been decades since anyone has documented any of the enormous fish successfully producing young that survive to adulthood in the upper Missouri River basin.

Date published: December 8, 2014

USGS and University of Wyoming Researchers to Share Deer Capture Field Work Via Social Media

Wyoming's struggling mule deer populations are receiving significant attention from University of Wyoming researchers, the Wyoming Game and Fish Department, the U.S. Geological Survey and others, with at least five studies underway that could assist efforts to enhance deer numbers and their habitats.

Date published: September 29, 2014

Wind Turbine or Tree? Certain Bats Might Not Know

Certain bats may be approaching wind turbines after mistaking them for trees, according to a study published in the Proceedings of the National Academy of Sciences.

Date published: February 12, 2014

Identifying Bats By Sound

Recording bats' echolocation "calls" is the most efficient and least intrusive way of identifying different species of bats in a given area, providing insight into some populations that have been decimated by white-nose syndrome.