Behavior and Ethology Commons^™

Patuxent’S Long-Term Research On Wolves, L. David Mech

USGS Northern Prairie Wildlife Research Center

The gray wolf (Canis lupus) was one of the first species placed on the Endangered Species List in 1967. The Endangered Species Act of 1973 legally protected the wolf along with other listed species.

Patuxent Wildlife Research Center (Patuxent) in Laurel, MD, began its Endangered Wildlife Program in 1966, and U.S. Fish and Wildlife Service (USFWS) biologist Ray Erickson was assigned to lead it. In 1973, I was transferred to the program from Region 3 of the USFWS, having been employed there since 1969 to study wolves in Minnesota.

Endangered Species Act protection of the wolf fostered its quick …

Wolf (Canis Lupus) Generation Time And Proportion Of Current Breeding Females By Age, L. David Mech, Shannon M. Barber-Meyer, John Erb

USGS Northern Prairie Wildlife Research Center

Information is sparse about aspects of female wolf (Canis lupus) breeding in the wild, including age of first reproduction, mean age of primiparity, generation time, and proportion of each age that breeds in any given year. We studied these subjects in 86 wolves (113 captures) in the Superior National Forest (SNF), Minnesota (MN), during 1972–2013 where wolves were legally protected for most of the period, and in 159 harvested wolves from throughout MN wolf range during 2012–2014. Breeding status of SNF wolves were assessed via nipple measurements, and wolves from throughout MN wolf range, by placental scars. In …

Territoriality And Inter-Pack Aggression In Gray Wolves: Shaping A Social Carnivore's Life History Rudyard Kipling's Law Of The Jungle Meets Yellowstone's Law Of The Mountains, Kira A. Cassidy, Douglas W. Smith, L. David Mech, Daniel R. Macnulty, Daniel R. Stahler, Matthew C. Metz

USGS Northern Prairie Wildlife Research Center

When Rudyard Kipling wrote The Jungle Book in 1894 and included the famous line "For the strength of the Wolf is the Pack, and the strength of the Pack is the Wolf," he would have had no idea that over a century later, scientific research would back up his poetic phrase. Recent studies in Yellowstone have found that both the individual wolf and the collective pack rely on each other and play important roles in territoriality. At a time when most fairy tales and fables were portraying wolves as demonic killers or, at best, slapstick gluttons, Kipling seemed to have …

Yellowstone Wolf (Canis Lupus) Density Predicted By Elk (Cervus Elaphus) Biomass, L. David Mech, Shannon M. Barber-Meyer

USGS Northern Prairie Wildlife Research Center

The Northern Range (NR) of Yellowstone National Park (YNP) hosts a higher prey biomass density in the form of elk (Cervus elaphus L., 1758) than any other system of gray wolves (Canis lupus L., 1758) and prey reported. Therefore, it is important to determine whether that wolf–prey system fits a long-standing model relating wolf density to prey biomass. Using data from 2005 to 2012 after elk population fluctuations dampened 10 years subsequent to wolf reintroduction, we found that NR prey biomass predicted wolf density. This finding and the trajectory of the regression extend the validity of the model …

Evaluation Of A Formula That Categorizes Female Gray Wolf Breeding Status By Nipple Size, Shannon M. Barber-Meyer, L. David Mech

USGS Northern Prairie Wildlife Research Center

The proportion by age class of wild Canis lupus (Gray Wolf) females that reproduce in any given year remains unclear; thus, we evaluated the applicability to our long-term (1972–2013) data set of the Mech et al. (1993) formula that categorizes female Gray Wolf breeding status by nipple size and time of year. We used the formula to classify Gray Wolves from 68 capture events into 4 categories (yearling, adult non-breeder, former breeder, current breeder). To address issues with small sample size and variance, we created an ambiguity index to allow some Gray Wolves to be classed into 2 categories. We …

Gray Wolf (Canis Lupus) Dyad Monthly Association Rates By Demographic Group, Shannon M. Barber-Meyer, L. David Mech

USGS Northern Prairie Wildlife Research Center

Preliminary data from GPS-collared wolves (Canis lupus) in the Superior National Forest of northeastern Minnesota indicated wolves had low association rates with packmates during summer. However, aerial-telemetry locations of very high frequency (VHF)-radioed wolves in this same area showed high associations among packmates during winter. We analyzed aerial-telemetry-location data from VHF-collared wolves in several packs (n=18 dyads) in this same area from 1994-2012 by month, and found lowest association rates occurred during June. While other studies have found low association among wolf packmates during summer, information on differences in association patterns depending on the wolf associates’ demographics is …

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.

Successes And Challenges From Formation To Implementation Of Eleven Broad-Extent Conservation Programs, Erik A. Beever, Brady J. Mattsson, Matthew J. Germino, Max Post Van Der Burg, John B. Bradford, Mark W. Brunson

USGS Northern Prairie Wildlife Research Center

Integration of conservation partnerships across geographic, biological, and administrative boundaries is increasingly relevant because drivers of change, such as climate shifts, transcend these boundaries. We explored successes and challenges of established conservation programs that span multiple watersheds and consider both social and ecological concerns. We asked representatives from a diverse set of 11 broadextent conservation partnerships in 29 countries 17 questions that pertained to launching and maintaining partnerships for broad-extent conservation, specifying ultimate management objectives, and implementation and learning. Partnerships invested more funds in implementing conservation actions than any other aspect of conservation, and a program’s context (geographic extent, United …

A Gray Wolf (Canis Lupus) Delivers Live Prey To A Pup, L. David Mech

USGS Northern Prairie Wildlife Research Center

A two-year-old sibling Gray Wolf (Canis lupus) carefully captured an Arctic Hare (Lepus arcticus) leveret alive on Ellesmere Island, Nunavut, Canada, and delivered it alive to a pup 28–33 days old. This appears to be the first observation of a Gray Wolf delivering live prey to a pup.

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

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 …

Use Of Real-Time Pcr To Detect Canine Parvovirus In Feces Of Free-Ranging Wolves, L. David Mech, Emily S. Almberg, Douglas Smith, Sagar Goyal, Randall S. Singer

USGS Northern Prairie Wildlife Research Center

Using real-time PCR, we tested 15 wolf (Canis lupus) feces from the Superior National Forest (SNF), Minnesota, USA, and 191 from Yellowstone National Park (YNP), USA, collected during summer and 13 during winter for canine parvovirus (CPV)-2 DNA. We also tested 20 dog feces for CPV-2 DNA. The PCR assay was 100%sensitive and specific with a minimum detection threshold of 104 50% tissue culture infective dose. Virus was detected in two winter specimens but none of the summer specimens. We suggest applying the technique more broadly especially with winter feces.

Wolves, Canis Lupus, Carry And Cache The Collars Of Radio-Collared White-Tailed Deer, Odocoileus Virginianus, They Killed, Michael E. Nelson, L. David Mech

USGS Northern Prairie Wildlife Research Center

Wolves (Canis lupus) in northeastern Minnesota cached six radio-collars (four in winter, two in spring-summer) of 202 radio-collared White-tailed Deer (Odocoileus virginianus) they killed or consumed from 1975 to 2010. A Wolf bedded on top of one collar cached in snow. We found one collar each at a Wolf den and Wolf rendezvous site, 2.5 km and 0.5 km respectively, from each deer’s previous locations.

Use Of Cranial Characters In Taxonomy Of The Minnesota Wolf (Canis Sp.), L. David Mech, Ronald M. Nowak, Sanford Weisberg

USGS Northern Prairie Wildlife Research Center

Minnesota wolves (Canis sp.) sometimes are reported to have affinity to a small, narrow-skulled eastern form (Canis lupus lycaon Schreber, 1775) and sometimes to a larger, broader western form (Canis lupus nubilus Say, 1823). We found that pre-1950 Minnesota wolf skulls were similar in size to those of wolves from southeastern Ontario and smaller than those of western wolves. However, Minnesota wolf skulls during 1970–1976 showed a shift to the larger, western form. Although Minnesota skull measurements after 1976 were unavailable, rostral ratios from 1969 through 1999 were consistent with hybridization between the smaller eastern wolf and …

Kin Encounter Rate And Inbreeding Avoidance In Canids, Eli Geffen, Michael Kam, Reuven Hefner, Pall Hersteinsson, Anders Angerbjorn, Love Dalen, Eva Fuglei, Karin Noren, Jennifer R. Adams, John Vucetich, Thomas J. Meier, L. David Mech, Bridgett M. Vonholdt, Daniel R. Stahler, Robert K. Wayne

USGS Northern Prairie Wildlife Research Center

Mating with close kin can lead to inbreeding depression through the expression of recessive deleterious alleles and loss of heterozygosity. Mate selection may be affected by kin encounter rate, and inbreeding avoidance may not be uniform but associated with age and social system. Specifically, selection for kin recognition and inbreeding avoidance may be more developed in species that live in family groups or breed cooperatively. To test this hypothesis, we compared kin encounter rate and the proportion of related breeding pairs in noninbred and highly inbred canid populations. The chance of randomly encountering a full sib ranged between 1–8% and …

Parsing Demographic Effects Of Canine Parvovirus On A Minnesota Wolf Population, L. David Mech, Sagar M. Goyal

USGS Northern Prairie Wildlife Research Center

We examined 35 years of relationships among wolf (Canis lupus) pup survival, population change and canine parvovirus (CPV) seroprevalence in northeastern Minnesota to determine when CPV exerted its strongest effects. Using correlation analysis of data from five periods of 7-years each from 1973 through 2007, we learned that the strongest effect of CPV on pup survival (r = -0.73) and on wolf population change (r = -0.92) was during 1987 to 1993. After that, little effect was documented despite a mean CPV seroprevalence from 1994 of 2007 of 70.8% compared with 52.6% during 1987 to 1993. We …

Movements Of Wolves At The Northern Extreme Of The Species’ Range, Including During Four Months Of Darkness, L. David Mech, H. Dean Cluff

USGS Northern Prairie Wildlife Research Center

Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species’ range in the High Arctic (.75uN latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching 253 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is .2,250 km south. We studied a pack of $20 wolves on Ellesmere Island, Nunavut, Canada (80°N latitude) from July 2009 …

The Scientific Classification Of Wolves: Canis Lupus Soupus, L. David Mech

USGS Northern Prairie Wildlife Research Center

Gray wolf, timber wolf, red wolf, eastern wolf, brush wolf, arctic wolf, Mexican wolf, maned wolf, Ethiopian wolf, etc., etc. How many kinds of wolves are there? And what are the differences? This is a really good question, and the answer is getting more complicated all the time. Let us start by going back a few years to the way science looked at wolves more traditionally— before the days of the new field of molecular genetics. Molecular genetics examines the actual DNA of animals and tries to classify them according to genetic similarities. ...

What does all this mean in …

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 …

Infectious Diseases In Yellowstone’S Canid Community, Emily S. Almberg, Paul C. Cross, L. David Mech, Doug W. Smith, Jennifer W. Sheldon, Robert L. Crabtree

USGS Northern Prairie Wildlife Research Center

Each summer Yellowstone Wolf Project staff visit den sites to monitor the success of wolf reproduction and pup rearing behavior. For the purposes of wolf monitoring, Yellowstone National Park (YNP) is divided into two study areas, the northern range and the interior, each distinguished by their ecological and physiographical differences. The 1,000 square kilometer northern range, characterized by lower elevations (1,500–2,200 m), serves as prime winter habitat for ungulates and supports a higher density of wolves than the interior (20–99 wolves/1,000 km² versus 2–11 wolves/1,000 km²). The interior of the park encompasses 7,991 square kilometers, is higher …

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 …

Prolonged Intensive Dominance Behavior Between Gray Wolves, Canis Lupus, L. David Mech, H. Dean Cluff

USGS Northern Prairie Wildlife Research Center

Dominance is one of the most pervasive and important behaviors among wolves in a pack, yet its significance in free-ranging packs has been little studied. Insights into a behavior can often be gained by examining unusual examples of it. In the High Arctic near Eureka, Nunavut, Canada, we videotaped and described an unusually prolonged and intensive behavioral bout between an adult male Gray Wolf (Canis lupus) and a male member of his pack, thought to be a maturing son.With tail raised, the adult approached a male pack mate about 50 m from us and pinned and straddled this …

What Is The Taxonomic Identity Of Minnesota Wolves?, L. David Mech

USGS Northern Prairie Wildlife Research Center

The taxonomic identity of the historical and current wolf (Canis lupus L., 1758 or Canis lycaon Schreber, 1775 or their hybrids) population in Minnesota (MN) and the Great Lakes region has been, and continues to be, controversial. So too does its legal status under the U.S. Endangered Species Act. This review summarizes the morphological and genetic information about that population and concludes that historically the MN population consisted of a gray wolf (C. lupus) in the west and an eastern type (Canis lupus lycaon or C. lycaon) in the east with intergrades or hybrids between …

Migration Of Northern Yellowstone Elk: Implications Of Spatial Structuring, P. J. White, Kelly M. Proffitt, L. David Mech, Shaney B. Evans, Julie A. Cunningham, Kenneth L. Hamlin

USGS Northern Prairie Wildlife Research Center

Migration can enhance survival and recruitment of mammals by increasing access to higher-quality forage or reducing predation risk, or both. We used telemetry locations collected from 140 adult female elk during 2000– 2003 and 2007–2008 to identify factors influencing the migration of northern Yellowstone elk. Elk wintered in 2 semidistinct herd segments and migrated 10–140 km to at least 12 summer areas in Yellowstone National Park (YNP) and nearby areas of Montana. Spring migrations were delayed after winters with increased snow pack, with earlier migration in years with earlier vegetation green-up. Elk wintering at lower elevations outside YNP migrated an …

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 …

Predatory Senescence In Ageing Wolves, Daniel R. Macnulty, Douglas W. Smith, John A. Vucetich, L. David Mech, Craig Packer

USGS Northern Prairie Wildlife Research Center

It is well established that ageing handicaps the ability of prey to escape predators, yet surprisingly little is known about how ageing affects the ability of predators to catch prey. Research into long-lived predators has assumed that adults have uniform impacts on prey regardless of age. Here we use longitudinal data from repeated observations of individually-known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park to demonstrate that adult predatory performance declines with age and that an increasing ratio of senescent individuals in the wolf population depresses the rate of prey offtake. Because this ratio fluctuates independently of …

Long Daily Movements Of Wolves, Canis Lupus, During Pup Rearing, L. David Mech, H. Dean Cluff

USGS Northern Prairie Wildlife Research Center

Wolves, Canis lupus, on Ellesmere Island traveled a daily round-trip distance of 40.2 km from their den to a landfill during July 2008, plus an undetermined distance hunting after leaving the landfill. Although long travels by Wolves are well known, this appears to be the first documentation of long daily movements by Wolves rearing pups.

Problems With The Claim Of Ecotype And Taxon Status Of The Wolf In The Great Lakes Region, Matthew A. Cronin, L. David Mech

USGS Northern Prairie Wildlife Research Center

Koblmuller et al. (2009) analyzed molecular genetic data of the wolf in the Great Lakes (GL) region of the USA and concluded that the animal was a unique ecotype of grey wolf and that genetic data supported the population as a discrete wolf taxon. However, some of the literature that the researchers used to support their position actually did not, and additional confusion arises from indefinite use of terminology. Herein, we discuss the problems with designation of a wolf population as a taxon or ecotype without proper definition and assessment of criteria.

Koblmuller et al. (2009) wrote ‘The GL …

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, …

A Serological Survey Of Infectious Disease In Yellowstone National Park’S Canid Community, Emily S. Almberg, L. David Mech, Douglas W. Smith, Jennifer W. Sheldon, Robert L. Crabtree

USGS Northern Prairie Wildlife Research Center

Background: Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park (YNP) after a .70 year absence, and as part of recovery efforts, the population has been closely monitored. In 1999 and 2005, pup survival was significantly reduced, suggestive of disease outbreaks.

Methodology/Principal Findings: We analyzed sympatric wolf, coyote (Canis latrans), and red fox (Vulpes vulpes) serologic data from YNP, spanning 1991–2007, to identify long-term patterns of pathogen exposure, identify associated risk factors, and examine evidence for disease-induced mortality among wolves for which there were survival data. We found high, constant exposure to canine …