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At least 487 records · Page 27Linked to original sources
USGS2010

Proportion of calves and adult muskoxen, Ovibos moschatus killed by gray wolves, Canis lupus, in July on Ellesmere Island

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 make it clear that adult muskoxen form an important part of the wolves' diet in July and thus possibly at other times during summer.

Canadian Field-Naturalist↗
USGS2011

Wolves, Canis lupus, carry and cache the collars of radio-collared White-tailed Deer, Odocoileus virginianus, they killed

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.

Minnesota↗
USGS2012

Gray Wolf (Canis lupus) movements and behavior around a kill site and implications for GPS collar studies

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 behavior around a kill. Combined with the literature, this observation supports placing a radio-collar on the breeding male to maximize finding kills via GPS collars and qualifying results depending on whatever other information is available about the collared wolf’s pack.

Ellesmere Island, Nunavut↗
USGS2013

Severe maxillary osteomyelitis in a Gray Wolf (Canis lupus)

Whereas dental injuries and abnormalities have been documented in Gray Wolves ( Canis lupus ), severe maxillary necrosis has not previously been implicated in a Gray Wolf fatality. Here I report maxillary osteomyelitis in a wild Gray Wolf from northeastern Minnesota of such severity that I hypothesize it ultimately led to death by starvation.

Canadian Field-Naturalist↗
USGS2013

Age structure of moose (Alces alces) killed by gray wolves (Canis lupus) in northeastern Minnesota, 1967-2011

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.

Minnesota↗
USGS2013

Indirect cannibalism by crèche-aged American White Pelican ( Pelecanus erythrorhynchos ) chicks

At nesting colonies of American White Pelicans (Pelecanus erythrorhynchos), many chicks die from siblicide, severe weather, and disease; this results in carcasses available for scavenging by conspecifics (i.e., indirect cannibalism). Indirect cannibalism has not been reported previously for this species. We describe five cases of crèche-aged American White Pelican chicks consuming or attempting to consume dead younger chicks at two nesting colonies in the northern plains of North America. Cannibalism in the American White Pelican appears to be rare and likely plays no role in the species’ population ecology or dynamics; however, it might be an important survival strategy of individual chicks when food resources are limited.

North Dakota;South Dakota↗
USGS2015

Experimental evidence of spatial memory and home range affinity in White-tailed Deer ( Odocoileus virginianus )

The role of spatial memory in the movement of animals through landscapes remains elusive. To examine spatial memory and home range affinity of White-tailed Deer ( Odocoileus virginianus ) in northeastern Minnesota during 1995–2007, I translocated 17 adult does with known home ranges to unfamiliar sites and radio-tracked them after their release. Twelve does wearing transmitting radio-collars returned to their home ranges. Death and collar expiration precluded determination of whether the remaining five does would have returned to home ranges. Three of five does wearing global positioning system collars traveled throughout hundreds of square kilometres, circling, backtracking, and returning to release sites, while two others exhibited directional movement for tens of kilometres. Four does that survived to parturition stopped traveling and moved at hourly rates similar to those of control does during the first three weeks of the typical fawn-rearing period, but continued traveling later. Their aberrant extensive travel before and after interruption by parturition suggests that they recognized they were in unfamiliar areas, demonstrating both their capacity and propensity to search for and occupy the familiar space of their individual home ranges. Their successful return to home ranges provided experimental evidence of spatial memory and further elucidated its pervasive role in White-tailed Deer spatial ecology.

Canadian Field-Naturalist↗
USGS2015

Record long-distance movement of a Deer Mouse, Peromyscus maniculatus , in a New England montane boreal forest

We report a single-season, non-homing movement of 4287 ± 10 m by an adult male Deer Mouse, Peromyscus maniculatus , in western Maine, United States, in summer 2014. The movement was achieved in two stages: 927 ± 3 m in four days and an additional 3360 ± 10 m in 44 days. This is approximately 40% greater than the previously documented maximum linear movement for an individual of this species.

Maine↗
USGS2015

Do ducks and songbirds initiate more nests when the probability of survival is greater?

Nesting chronology in grassland birds can vary by species, locality, and year. The date a nest is initiated can influence the subsequent probability of its survival in some grassland bird species. Because predation is the most significant cause of nest loss in grassland birds, we examined the relation between timing of nesting and nest survival. Periods of high nest survival that correspond with the peak of nesting activity might reflect long-term adaptations to specific predation pressures commonly recurring during certain periods of the nesting cycle. We evaluated this theory by comparing timing of nesting with date-specific nest survival rates for several duck and passerine species breeding in north-central North Dakota during 1998–2003. Nest survival decreased seasonally with date for five of the seven species we studied. We found little evidence to support consistent relations between timing of nesting, the number of nest initiations, and nest survival for any species we studied, suggesting that factors other than nest predation may better explain nesting chronology for these species. The apparent mismatch between date-specific patterns of nest survival and nest initiation underscores uncertainty about the process of avian nest site selection driven mainly by predation. Although timing of nesting differed among species, the general nesting period was fairly predictable across all years of study, suggesting the potential for research activities or management actions to be timed to take advantage of known periods when nests are active (or inactive). However, our results do not support the notion that biologists can take advantage of periods when many nests are active and survival is also high.

North Dakota↗
USGS2016

White-tailed Deer ( Odocoileus virginianus ) fawn risk from Gray Wolf ( Canis lupus ) predation during summer

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.

Minnesota↗
USGS2017

White-tailed deer (Odocoileus virginianus) subsidize gray wolves (Canis lupus) during a moose (Alces americanus) decline: A case of apparent competition?

Moose ( Alces americanus ) in northeastern Minnesota have declined by 55% since 2006. Although the cause is unresolved, some studies have suggested that Gray Wolves ( Canis lupus ) contributed to the decline. After the Moose decline, wolves could either decline or switch prey. To determine which occurred in our study area, we compared winter wolf counts and summer diet before and after the Moose decline. While wolf numbers in our study area nearly doubled from 23 in winter 2002 to an average of 41 during winters 2011–2013, calf:cow ratios (the number of calves per cow observed during winter surveys) in the wider Moose range more than halved from 0.93 in 2002 to an average of 0.31 during 2011–2013. Compared to summer 2002, wolves in summers 2011–2013 consumed fewer Moose and more White-tailed Deer ( Odocoileus virginianus ). While deer densities were similar during each period, average vulnerability, as reflected by winter severity, was greater during 2011–2013 than 2002, probably explaining the wolf increase. During the wolf increase Moose calves remained a summer food item. These findings suggest that in part of the Moose range, deer subsidized wolf numbers while wolves also preyed on Moose calves. This contributed to a Moose decline and is a possible case of apparent competition and inverse-density-dependent predation.

Canadian Field-Naturalist↗
USGS2017

Extinguishing a learned response in a free-ranging gray wolf (Canis lupus)

A free-ranging Gray Wolf (Canis lupus), habituated to human presence (the author) on Ellesmere Island, Canada, learned to anticipate experimental feeding by a human, became impatient, persistent, and bold and exhibited stalking behaviour toward the food source. Only after the author offered the wolf about 90 clumps of dry soil over a period of 45 minutes in three bouts, did the wolf give up this behaviour. To my knowledge, this is the first example of extinguishing a learned response in a free-ranging wolf and provides new insight into the learning behaviour of such animals.

Ellesmere Island↗
USGS2019

Gray Wolf (Canis lupus) recolonization failure: A Minnesota case study

During the past few decades, Gray Wolves ( Canis lupus ) have recolonized many areas in the United States and Europe. In many other cases, however, although dispersing wolves reached areas with adequate prey, a population failed to recolonize. Herein, we provide a case study detailing how a wolf pack attempted for three years to recolonize an area 55 km from a long-established population and within 25 km of Minneapolis and St. Paul, Minnesota, but failed. The pack produced three litters of pups and at one time included 11–19 members, but it preyed on livestock and dogs and, consequently, was lethally removed. The history of this pack’s attempt to recolonize an area long devoid of wolves exemplifies the issues that have prevented earlier recolonizations in non-wild lands in Minnesota and elsewhere and that promise to do so well into the future.

Minnesota↗
USGS2020

Sixty years of White-tailed Deer (Odocoileus virginianus) yarding in a Gray Wolf (Canis lupus)–deer system

This article synthesizes information from over a six-decade period of studies of White-tailed Deer ( Odocoileus virginianus ) use of a winter yard and subject to Gray Wolf ( Canis lupus ) predation in northeastern Minnesota. It also adds spring migration data from 35 adult female deer and fawns studied there during 1998, 1999, 2001, 2014, and 2017. Twenty-nine of these deer migrated in spring a mean distance of 29 km (SE = 4), a maximum distance of 78 km, and at a mean bearing of 83° (SE = 12; range 21–348). These findings are similar to those from 49 deer (both sexes) from the same yard studied during 1974–1984, that migrated a mean distance of 25 km (SE = 1.8) and a mean bearing of 77° ± 4 SE. Between the two periods, the wolf population fluctuated considerably, the winter range of deer in the area where these deer spent summer greatly diminished, and both derechos and fires disturbed the habitat. This study attests to the selective advantage of the migratory tradition of deer in this yard.

Minnesota↗
USGS2022

Key observations of flexed-leg urination in the free-ranging Gray Wolf (Canis lupus)

Flexed-leg urination (FLU) in female Gray Wolves ( Canis lupus ) has been little studied in the wild. Captive females in packs do not exhibit FLU unless they are both mature and dominant to an associate female, but these characteristics have not been confirmed in free-ranging wolves. We present observations of wolves in Yellowstone National Park that accord with those of wolves in captivity, extend our knowledge of FLU in Gray Wolf, pose additional questions about it, and suggest new areas of study to better understand it.

Wyoming↗
USGS1943

Age determination in juvenal bobwhite quail

Following methods described by Louis Bureau (1911, 1913) in France, tabulations were made (1) of the ages at which captivity-reared bob-white quail ( Colinus virginianus ) dropped their juvenal remiges, and (2) the rates at which post-juvenal replacement primaries grew. These were arranged so as to permit the determination of age in healthy birds from one to five months of age. The degree of individual variation was much greater than that found by Bureau, however, and limits accuracy in age determination after the 10th week. The post-juvenal wing molt began on the birds' 28th day and ended when the quail were 146 to 154 days old. The post-juvenal body molt was found to take place largely between the 70th and 100th days. The juvenal rectrices were renewed from the 62nd to the 122nd days, the new feathers being as long as their longest coverts when the birds were 116 days old. The color of the tarsi varied from pink, at 32 days of age, to straw color at 60 days, and yellow-gray from 83 to 180 days. At six months, the color of the beak was identical with that of adults. Unlike several other game bird species, the flexibility of the lower jaw was not an accurate index to age in bob-whites older than 11 weeks. Rigor mortis and freezing were found to hinder the testing of this criterion.

American Midland Naturalist↗