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Terrestrial and Aquatic Ecology

Predation

USGS Northern Prairie Wildlife Research Center

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Full-Text Articles in Life Sciences

An Historical Overview And Update Of Wolf-Moose Interactions In Northeastern Minnesota, L. David Mech, John Fieberg, Shannon M. Barber-Meyer Jan 2018

An Historical Overview And Update Of Wolf-Moose Interactions In Northeastern Minnesota, L. David Mech, John Fieberg, Shannon M. Barber-Meyer

USGS Northern Prairie Wildlife Research Center

Wolf (Canis lupus) and moose (Alces americanus) populations in northeastern Minnesota, USA, have fluctuated for decades and, based on helicopter counts, moose numbers declined to a new low from 2006 to about 2012. Other steep declines were found in 1991 and 1998 during periods when moose counts were done with fixed-wing aircraft; these declines also appeared to be real. Winter wolf numbers, monitored in part of the moose range, had been increasing since about 2002 to the highest population in decades in 2009. However, from 2009 to 2016, wolves decreased precipitously, and the moose- population decline leveled …


White-Tailed Deer (Odocoileus Virginianus) Fawn Risk From Gray Wolf (Canis Lupus) Predation During Summer, L. David Mech, Aaron Morris, Shannon M. Barber-Meyer Jan 2015

White-Tailed Deer (Odocoileus Virginianus) Fawn Risk From Gray Wolf (Canis Lupus) Predation During Summer, L. David Mech, Aaron Morris, Shannon M. Barber-Meyer

USGS Northern Prairie Wildlife Research Center

Little is known about how often various prey animals are at risk of predation by Gray Wolves (Canis lupus). We used a system to monitor the presence during the day of two radio-collared Gray Wolves within 2 km of a radio-collared White-tailed Deer (Odocoileus virginianus) with a fawn or fawns in August 2013 in the Superior National Forest of northeastern Minnesota. We concluded that the fawn or fawns were at risk of predation by at least one wolf at least daily.


Age Structure Of Moose (Alces Alces) Killed By Gray Wolves (Canis Lupus) In Northeastern Minnesota, 1967–2011, L. David Mech, Michael E. Nelson Jan 2013

Age Structure Of Moose (Alces Alces) Killed By Gray Wolves (Canis Lupus) In Northeastern Minnesota, 1967–2011, L. David Mech, Michael E. Nelson

USGS Northern Prairie Wildlife Research Center

The ages of 77 adult Moose (Alces alces) killed by gray Wolves (Canis lupus) during the period 1967–2011 in northeastern Minnesota were significantly older than those of a sample of 17 585 Moose killed by hunters in nearby Ontario. Our findings support those of earlier studies of protected Moose populations in national parks that found that gray Wolves tend to kill disproportionately more older Moose.


Nonlinear Effects Of Group Size On The Success Of Wolves Hunting Elk, Daniel R. Macnulty, Douglas W. Smith, L. David Mech, John A. Vucetich, Craig Packer Jan 2012

Nonlinear Effects Of Group Size On The Success Of Wolves Hunting Elk, Daniel R. Macnulty, Douglas W. Smith, L. David Mech, John A. Vucetich, Craig Packer

USGS Northern Prairie Wildlife Research Center

Despite the popular view that social predators live in groups because group hunting facilitates prey capture, the apparent tendency for hunting success to peak at small group sizes suggests that the formation of large groups is unrelated to prey capture. Few empirical studies, however, have tested for nonlinear relationships between hunting success and group size, and none have demonstrated why success trails off after peaking. Here, we use a unique dataset of observations of individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to show that the relationship between success and group …


Gray Wolf (Canis Lupus) Movements And Behavior Around A Kill Site And Implications For Gps Collar Studies, L. David Mech Jan 2011

Gray Wolf (Canis Lupus) Movements And Behavior Around A Kill Site And Implications For Gps Collar Studies, L. David Mech

USGS Northern Prairie Wildlife Research Center

Global Positioning System (GPS) radio-collars are increasingly used to estimate Gray Wolf (Canis lupus) kill rates. In interpreting results from this technology, researchers make various assumptions about wolf behavior around kills, yet no detailed description of this behavior has been published. This article describes the behavior of six wolves in an area of constant daylight during 30 hours, from when the pack killed a Muskox (Ovibos moschatus) calf and yearling on Ellesmere Island, Nunavut, Canada, to when they abandoned the kill remains. Although this is only a single incident, it demonstrates one possible scenario of pack …


Problems With Studying Wolf Predation On Small Prey In Summer Via Global Positioning System Collars, Vicente Palacios, L. David Mech Jan 2011

Problems With Studying Wolf Predation On Small Prey In Summer Via Global Positioning System Collars, Vicente Palacios, L. David Mech

USGS Northern Prairie Wildlife Research Center

We attempted to study predation on various-sized prey by a male and female wolf (Canis lupus) with global positioning system (GPS) collars programmed to acquire locations every 10 min in the Superior National Forest of Minnesota. During May to August 2007, we investigated 147 clusters of locations (31% of the total) and found evidence of predation on a white-tailed deer (Odocoileus virginianus) fawn and yearling, a beaver (Castor canadensis), ruffed grouse (Bonasa umbellus), and fisher (Martes pennanti) and scavenging on a road-killed deer and other carrion. However, we missed finding …


Proportion Of Calves And Adult Muskoxen, Ovibos Moschatus Killed By Gray Wolves, Canis Lupus, In July On Ellesmere Island, L. David Mech Jan 2010

Proportion Of Calves And Adult Muskoxen, Ovibos Moschatus Killed By Gray Wolves, Canis Lupus, In July On Ellesmere Island, L. David Mech

USGS Northern Prairie Wildlife Research Center

Generally Gray Wolves (Canis lupus L., 1758) tend to focus predation on young-of-the-year ungulates during summer, and I hypothesized that wolves preying on Muskoxen (Ovibos moschatus Zimmerman, 1780) in summer would follow that trend. Over 23 July periods observing wolves on Ellesmere Island, Nunavut, Canada, I found that packs of 2-12 adult wolves killed seven calves, one yearling, and five adult muskoxen at distances of 2.9 to 32 km from their current dens and pups. Given a possible bias against finding calves because of their fewer remains, these results do not necessarily refute the hypothesis, but they do …


Wolf, Canis Lupus, Visits To White-Tailed Deer, Odocoileus Virginianus, Summer Ranges: Optimal Foraging?, Dominic J. Demma, L. David Mech Jan 2009

Wolf, Canis Lupus, Visits To White-Tailed Deer, Odocoileus Virginianus, Summer Ranges: Optimal Foraging?, Dominic J. Demma, L. David Mech

USGS Northern Prairie Wildlife Research Center

We tested whether Wolf (Canis lupus) visits to individual female White-tailed Deer (Odocoileus virginianus) summer ranges during 2003 and 2004 in northeastern Minnesota were in accord with optimal-foraging theory. Using GPS collars with 10- to 30-minute location attempts on four Wolves and five female deer, plus eleven VHF-collared female deer in the Wolves’ territory, provided new insights into the frequency of Wolf visits to summer ranges of female deer. Wolves made a mean 0.055 visits/day to summer ranges of deer three years and older, significantly more than their 0.032 mean visits/day to ranges of two-year-old deer, …


Factors Influencing Predation On Juvenile Ungulates And Natural Selection Implications, S. M. Barber-Meyer, L. D. Mech Jan 2008

Factors Influencing Predation On Juvenile Ungulates And Natural Selection Implications, S. M. Barber-Meyer, L. D. Mech

USGS Northern Prairie Wildlife Research Center

Juvenile ungulates are generally more vulnerable to predation than are adult ungulates other than senescent individuals, not only because of their relative youth, fragility, and inexperience, but also because of congenital factors. Linnell et al.’s (Wildl. Biol. 1: 209-223) extensive review of predation on juvenile ungulates concluded that research was needed to determine the predisposition of these juveniles to predation. Since then, various characteristics that potentially predispose juvenile ungulates have emerged including blood characteristics, morphometric and other condition factors, and other factors such as birth period, the mother’s experience, and spatial and habitat aspects. To the extent that any of …


Elk Calf Survival And Mortality Following Wolf Restoration To Yellowstone National Park La Supervivencia Y La Mortalidad De Las Crı´As De Wapiti Tras La Restauracio´ N Del Lobo Al Parque Nacional De Yellowstone La Survie Et La Mortalite´ Des Faons De Wapitis Qui A Suivi La Re´Introduction Du Loup Au Parc De Yellowstone, S. M. Barber-Meyer, L. David Mech, P. J. White Jan 2008

Elk Calf Survival And Mortality Following Wolf Restoration To Yellowstone National Park La Supervivencia Y La Mortalidad De Las Crı´As De Wapiti Tras La Restauracio´ N Del Lobo Al Parque Nacional De Yellowstone La Survie Et La Mortalite´ Des Faons De Wapitis Qui A Suivi La Re´Introduction Du Loup Au Parc De Yellowstone, S. M. Barber-Meyer, L. David Mech, P. J. White

USGS Northern Prairie Wildlife Research Center

We conducted a 3-year study (May 2003–Apr 2006) of mortality of northern Yellowstone elk (Cervus elaphus) calves to determine the cause for the recruitment decline (i.e., 33 calves to 13 calves/100 adult F) following the restoration of wolves (Canis lupus). We captured, fit with radiotransmitters, and evaluated blood characteristics and disease antibody seroprevalence in 151 calves ≤ 6 days old (68M:83F). Concentrations (x, SE) of potential condition indicators were as follows: thyroxine (T4; 13.8 µg/dL, 0.43), serum urea nitrogen (SUN; 17.4 mg/dL, 0.57), c-glutamyltransferase (GGT; 66.4 IU/L, 4.36), gamma globulins (GG; 1.5 g/dL, 0.07), and insulin-like …


Winter Severity And Wolf Predation On A Formerly Wolf-Free Elk Herd, L. David Mech, Douglas W. Smith, Kerry M. Murphy, Daniel R. Macnulty Oct 2001

Winter Severity And Wolf Predation On A Formerly Wolf-Free Elk Herd, L. David Mech, Douglas W. Smith, Kerry M. Murphy, Daniel R. Macnulty

USGS Northern Prairie Wildlife Research Center

We studied wolf (Canis lupus) predation on elk (Cervus elaphus) in Yellowstone National Park from 17 March to 15 April 1997 (severe winter conditions) and from 2 to 31 March 1998 (mild winter conditions) 2-3 years after wolves were reintroduced to the park. Elk composed 91% of 117 kills. Data comparisons for 1997 versus 1998 were: hunting success rate, 26% versus 15%; kill rate, 17.1 kg/wolf/day versus 6.1; percent of kill consumed in first day, 7 versus 86; percent femur marrow fat of adult kills, 27 versus 70; calf:adult ratios of kills, 2:33 versus 17:23; sex …


Proximity Of White-Tailed Deer, Odocoileus Virginianus, Ranges To Wolf, Canis Lupus, Pack Homesites, Michael E. Nelson, L. David Mech Jan 2000

Proximity Of White-Tailed Deer, Odocoileus Virginianus, Ranges To Wolf, Canis Lupus, Pack Homesites, Michael E. Nelson, L. David Mech

USGS Northern Prairie Wildlife Research Center

Seven adult female White-tailed Deer (Odocoileus virginianus) in northeastern Minnesota lived within 1.8 km of Wolf pack (Canis lupus) homesites without vacating their home ranges. Six of these deer and at least three of their fawns survived through the Wolf homesite period.


Assessing Factors That May Predispose Minnesota Farms To Wolf Depredations On Cattle, L. David Mech, Elizabeth K. Harper, Thomas J. Meier, William J. Paul Jan 2000

Assessing Factors That May Predispose Minnesota Farms To Wolf Depredations On Cattle, L. David Mech, Elizabeth K. Harper, Thomas J. Meier, William J. Paul

USGS Northern Prairie Wildlife Research Center

Wolf (Canis lupus) depredations on livestock cause considerable conflict and expense in Minnesota. Furthermore, claims are made that such depredations are fostered by the type of animal husbandry practiced. Thus, we tried to detect factors that might predispose farms in Minnesota to wolf depredations. We compared results of interviews with 41 cattle farmers experiencing chronic cattle losses to wolves (chronic farms) with results from 41 nearby "matched" farms with no wolf losses to determine farm characteristics or husbandry practices that differed and that therefore might have affected wolf depredations. We also used a Geographic Information System (GIS) to …