Population Dynamics

CWD is a degenerative neurological disease caused by infectious proteins called prions. Although documented cases are invariably fatal, infected elk commonly survive for several months or longer, passing prions directly to other individuals and into the environment, where they bind to surfaces or soils and can persist for years. CWD reached Wind Cave National Park about 1997 and rapidly became the...

Badlands National Park contains the largest contiguous bison range in the core of the species’ historic range on the northern Great Plains. The park nevertheless is too small to accommodate natural movements of free-ranging bison. As a result, continual grazing by resident bison has supplanted intense-but-ephemeral grazing by nomadic bison. The herd also is currently too small to prevent gradual...

Wolves on Ellesmere Island, just south of the North Pole, survive in extreme cold during 24 hours of darkness per day from November through January, and survive in much higher temperatures during 24 hours of light per day from April through September. Partnering with other agencies, we use GPS radio collars applied to wolves during summer to examine wolf-pack movements on Ellesmere Island...

The National Park Service and U.S. Fish and Wildlife Service reintroduced wolves into Yellowstone National Park in 1995 and 1996. This study helps assess that population’s recovery and determine factors that affect the population, including diseases, intraspecific strife, and interactions with prey. The restoration has been very successful, and the population has persisted for more than 20 years...

When the wolf was listed as endangered, the last remaining mainland wolf population in the lower 48 states was in the Superior National Forest (SNF) of northeastern Minnesota. Since then, using radiocollaring and aerial tracking, we have studied the wolf population trend, factors influencing it, and prey species, white-tailed deer, moose, and beavers, affected by wolves. During winter 2018-2019...

The only self-sustaining population of endangered whooping cranes nests within and near Wood Buffalo National Park, Canada, migrates through the Great Plains, and winters primarily along the Texas Gulf Coast. Our objectives of this collaborative project are to address the entire annual life cycle of this species by advancing knowledge of breeding, wintering, and migration ecology, including...

Least terns and piping plovers are the subject of numerous population monitoring efforts. Population monitoring requires periodic visits to nesting areas to count and assess breeding status of the birds. At higher visit frequencies, detection of nests and chicks improves as does ability to determine outcomes of nesting attempts, resulting in more complete and accurate productivity information. But...

The Platte River Recovery Implementation Program (PRRIP) partnered with Northern Prairie Wildlife Research Center (NPWRC) to study demographics of least terns and piping plovers at the Central Platte River in Nebraska. Due to water management and other alterations, riverine habitat for least terns and piping plovers has become degraded. Least terns and piping plovers, however, have begun breeding...

Northern Prairie Wildlife Research Center (NPWRC) is helping to improve the monitoring of federally listed least terns and piping plovers by the U.S. Army Corps of Engineers at John Martin Reservoir in Southeastern Colorado. NPWRC is providing information to the USACE aimed to improve their habitat management and productivity monitoring. NPWRC is also providing the capability to mark adults and...

NPWRC is leading a multi-agency study to understand metapopulation dynamics of piping plovers in the Northern Great Plains. Piping plovers are a federally listed species that nests on riverine sandbars and shorelines of wetlands and reservoirs. These habitats are dynamic in response to climate and water-management regimes of the Missouri River. The US Army Corps of Engineers manages the Missouri...

The largest recorded flood event on the Missouri River occurred during 2011. Northern Prairie Wildlife Research Center recently concluded a study that evaluated effects of that flood on least tern and piping plover breeding populations. These federally-listed species nest on riverine sandbars and reservoir shorelines. Since construction of the dams on the Missouri River there have been few floods...

The North American Breeding Bird Survey (BBS) provides much essential information for assessing bird populations, but it is unknown how inherent assumptions of the BBS apply to grassland birds in the Northern Plains. Understanding the effects of these assumptions on our understanding of grassland bird populations is essential given widespread declines of grassland birds as well as recent and...