The health of Colorado's bighorn sheep population remains as precarious as the steep alpine terrain the animals inhabit, but a new study led by researchers at the University of Colorado Boulder has found that inbreeding--a common hypothesis for a recent decline--likely isn't to blame.
Bighorn herds tend to be small and isolated in their mountain ecosystems, putting the animals at high risk for a genetic "bottleneck," said Catherine Driscoll, a graduate student in the Department of Ecology and Evolutionary Biology at CU-Boulder and lead author of the study. Previous research has shown that inbreeding can weaken a population's immunity to disease across subsequent generations.
However, after using mitochondrial DNA data to analyze a diverse set of hereditary markers, researchers found that all five native herds in Rocky Mountain National Park (RMNP) are maintaining healthy levels of genetic variation compared to other bighorn populations across the western United States.
"There's been enough gene flow between the herds, primarily due to high ram migration, that the population has been genetically rescued," Driscoll said.
The findings, which were recently published in the Journal of Wildlife Management, suggest that other factors such as nutritional deficiencies, habitat fragmentation and competition from encroaching mountain goats may play a more significant role in depressing bighorn population growth.
The researchers used DNA testing to examine genetic diversity across five separate RMNP herds. In particular, the study zeroed in on the Mummy herd, which experienced a severe population crash in the mid-1990s and has been especially slow to recover.
Although the Mummy herd is maintaining healthy levels of genetic variation, it may still carry higher exposure to stress factors due to its proximity to roads and trails on the eastern side of RMNP.
Colorado's bighorn population has trended downward since the 1800s, including a sharp 10.2 percent drop between 2001 and 2009. Wildlife managers have occasionally transplanted bighorns from other states in an attempt to restore herd numbers.
In addition to RMNP, bighorns can frequently be spotted at popular viewing destinations such as Mt. Evans, the Colorado National Monument and near Georgetown along Interstate 70.
Jeffry Mitton, a professor in the Department of Ecology and Evolutionary Biology at the University of Colorado Boulder; James G. Driscoll, a researcher at the Blue Basin Wildlife Sanctuary; Corey Hazekamp, a research assistant at the University of Massachusetts; and John D. Wehausen, a research associate at the University of California San Diego, co-authored the study.
The National Park Service, Rocky Mountain National Park, the National Science Foundation, the Rocky Mountain Nature Association, the Indian Peaks Wilderness Alliance and the University of Colorado Boulder provided funding for the research.
Trent Knoss, CU-Boulder media relations, 303-735-0528
Catherine Driscoll | EurekAlert!
Bioinvasion on the rise
15.02.2017 | Universität Konstanz
Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
17.02.2017 | Medical Engineering
17.02.2017 | Medical Engineering
17.02.2017 | Health and Medicine