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Geology topics

L. David Mech

Publications and source records attributed to L. David Mech.

At least 19 recordsLinked to original sources
USGS2023

The challenges of success: Future wolf conservation and management in the United States

Gray wolf ( Canis lupus ) recovery and conservation has been a remarkable success over the last 30 years in the United States. Remarkable success yields remarkable challenges, however. As populations expand, wolves will colonize more human-dominated landscapes and face numerous challenges, such as fragmented habitats, barriers to dispersal, and increased encounters with humans, pets, and livestock. In such areas, conflicts between humans and wolves will increase. We summarize several major scientific and social challenges that wolf conservation, recovery, and management will face in the coming years. In addition, we suggest actions to help address each challenge. Future wolf conservation in the United States will be affected by the ability of managers to predict colonization and dispersal dynamics, to reduce hybridization and disease transmission, to mitigate and deter wolf–livestock conflicts, to harvest wolves sustainably while satisfying diverse stakeholders, to avert a reduction in tolerance for wolves due to a disinterest in nature, and to engage diverse stakeholders in wolf conservation to avoid management by ballot initiative or legislative and judicial decrees.

contiguous United States↗
USGS2023

Geographic isolation reduces genetic diversity of a wide-ranging terrestrial vertebrate, Canis lupus

Genetic diversity is theorized to decrease in populations closer to a species' range edge, where habitat may be suboptimal. Generalist species capable of long-range dispersal may maintain sufficient gene flow to counteract this, though the presence of significant barriers to dispersal (e.g., large water bodies, human-dominated landscapes) may still lead to, and exacerbate, the edge effect. We used microsatellite data for 2421 gray wolves ( Canis lupus ) from 24 subpopulations (groups) to model how allelic richness and expected heterozygosity varied with mainland–island position and two measures of range edge (latitude and distance from range center) across >7.3 million km 2 of northern North America. We expected low genetic diversity both at high latitudes, due to harsh environmental conditions, and on islands, but no change in diversity with distance to the range center due to the species' exceptional dispersal ability and favorable conditions in far eastern and western habitats. We found that allelic richness and expected heterozygosity of island groups were measurably less than that of mainland groups, and that these differences increased with the island's distance to the species' range center in the study area. Our results demonstrate how multiple axes of geographic isolation (distance from range center and island habitation) can act synergistically to erode the genetic diversity of wide-ranging terrestrial vertebrate populations despite the counteracting influence of long-range dispersal ability. These findings emphasize how geographic isolation is a potential threat to the genetic diversity and viability of terrestrial vertebrate populations even among species capable of long-range dispersal.

Alaska↗
USGS2023

A field test of R package GPSeqClus: For establishing animal location clusters

The ability to track animals with Global Positioning System (GPS) collars opened an enormous potential for studying animal movements and behaviour in their natural environment. One such endeavour is to identify clusters of GPS locations as a way to estimate predator kill rate. Clapp et al. (2021) developed an R package ( GPSeqClus ) to assess a location dataset based on user-defined parameters to identify clusters and their characteristics. These characteristics can then help to distinguish resting-site clusters from kill sites of their large (>50 kg) prey. We identified location clusters of an adult male wolf Canis lupus on Ellesmere Island, Nunavut, Canada in July 2009 and tracked him until he died in April 2010. Identifying location clusters was challenging because the collar only obtained two GPS locations per day (12 h apart). In July 2010, we searched 30 of 52 location-clusters we identified as kill/scavenge sites and found 17 of them as such, given they had muskox Ovibos moschatus or caribou Rangifer tarandus pearyi remains nearby. We also documented five wolf rendezvous sites, two den sites, and the wolf's death site to total 60 location-clusters in all. We used a two-step process in testing the R Package GPSeqClus (hereafter GPSeqClus ): (1) compare the number of clusters our method discerned with the number identified by the new algorithm, and (2) compare the number of biologically significant clusters (e.g. den sites, kill/feeding sites) we found with the number the new algorithm located. We made these tests with GPSeqClus by varying the search radius, number of days at a site, and minimum number of locations required for a cluster. GPSeqClus compared well to our technique, with the best sub-algorithm among the 25 we tested only missing three of our identified clusters and yielding six additional clusters. GPSeqClus identified 16 of the 17 confirmed sites of remains, all wolf home sites, and the wolf's carcass site. Identifying clusters using a 500-m search radius, a 1.5-day window, and a minimum of two GPS locations per cluster was suitable for a coarse GPS acquisition rate of two locations per day when prey are large, such as muskox or caribou. Given that GPSeqClus performed well with our coarse location dataset, we expect it will also perform even better with a collar acquiring more than two locations per day. Having a field-tested utility such as GPSeqClus will enhance carnivore predation studies elsewhere.

Ecological Solutions and Evidence↗
USGS2023

A plea for Red Wolf conservation throughout Its recent distribution

Canis rufus (Red Wolf) is one of the most endangered mammals in North America. However, genes of the Red Wolf persist across much of the species' original range, carried predominantly within C. latrans (Coyote) populations. It is now known that such genes are distributed from extreme north-central Texas through most of eastern Texas to southern Louisiana. Publicizing of the most recent findings of Red Wolf genes in Coyotes of southern Louisiana emphasized that area for intensive conservation efforts. Such efforts could be applied throughout the entire known distribution of those rare genes, not just in the small area of southern Louisiana recently publicized. Because conservation efforts might be hindered by local conditions and circumstances, expanding geographic options for their application could make the difference in their success.

Southesatern Naturalist↗
USGS2022

Automatic recorders monitor wolves at rendezvous sites: do wolves adjust howling to live near humans?

We used automatic sound recorders to study spontaneous vocalizations of wild wolves during the pup-rearing season around rendezvous sites from 24 wolf packs in six study areas across North America, Asia, and Europe. Between 2018 and 2021, for a total of 1225 pack-days, we recorded 605 spontaneous wolf chorus howls and 224 solo-howl series. Howling occurrence varied across areas, from 12.50 to 94.12% days with howling. Daily howling ranged from 0.00 to 3.47 solo howls/day and 0.13 to 5.29 chorus howls/day. Generally, spontaneous chorus howls peaked between sunset and sunrise. Howling rate depended on area, pack size, and density of people living nearby, being greater where fewer people lived. High rates in Yellowstone National Park, (800,000+ visitors during the study) could reflect accommodation to human activities such as wolf watching. One to six automatic recorders per site within 1000 m of rendezvous sites needed 4–15 days to detect the pack (average 9.5) and 5–21 days (average 11.3) to detect pups, both with a probability of 95%. Our results may guide wolf-monitoring programs using automatic sound recorders, a promising method offering advantages over howling surveys, especially in human-dominated landscapes.

Biodiversity and Conservation↗
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↗
USGS2022

Newly documented behavior of free-ranging Arctic wolf pups

Whereas much is known about the behavior and development of captive young wolf ( Canis lupus ) pups, less detail has been published about some aspects of free-ranging wolf pup behavior. This article synthesizes 42 observations of free-ranging Arctic wolf pups from ages 13 through 52 days made during 10 summers from 1987 through 2006 on Ellesmere Island, Nunavut, Canada. Besides listing key behaviors such as howling and caching, I record unique observations of ages of pup urination without adult stimulation (22, 33, 42, 52 days), knowledge of which is important to studies of wolf domestication, and of a 48-day-old pup that traveled 39 km during a 12 h and 19 min round trip between the den and a prey carcass, including a 26.5 km trek in 5 h. These observations should lead to a deeper and more complete understanding of this critical period of pup growth and development.

Nunavut↗
USGS2021

An assessment of current wolf Canis lupus domestication hypotheses based on wolf ecology and behaviour

The dog was the first domesticated animal. Its derivation from grey wolves Canis lupus is important to the study of mammalian domestication, and wolf domestication is an active area of investigation. Recent popular books have promoted a hypothesis that wolves domesticated themselves as opposed to the earliest hypothesis that featured pup collection, adoption, and artificial selection. Continuing research has produced a greater understanding of wolf ecology and behaviour, including new insights into the wolf’s interaction with humans. Several characteristics make the wolf conducive to domestication: its sociality, catholic diet, excellent individual and cultural memory, inbreeding tolerance, varied personalities, and adaptable lifestyle. The wolf’s fear of humans is the main impediment and that alone is a factor strongly disfavouring the self-selection hypothesis. However, collecting young pups from dens and raising them would foster their socialising with humans as pack members. Neither hypothesis explains how wolves undergoing domestication were separated reproductively from their wild relatives, an important condition for domestication. We combine information from the literature with information from our own research on wild wolves, archaeology, and canid morphology. We explain how pup collection and deliberate or incidental selection and encouragement to breed with similarly raised wolves could keep incipient dogs separated reproductively from wild relatives. The key is humans regularly feeding the wolves and keeping only those able to live harmoniously with humans. Well-fed, human-dependent wolves would remain near their food supply and in the company of humans, thus increasing their bonds to humans and vice versa . Outbreeding with wild wolves would thus be avoided. Generation after generation of these human-fed, raised, and selected wolves would become increasingly dependent on humans and shaped by them. The pup-adoption hypothesis presented here is more in keeping with basic wolf ecology and behaviour than the self-domestication hypothesis.

Current Biology↗
USGS2021

Behaviorally-mediated trophic cascade attenuated by prey use of risky places at safe times

The mere threat of predation may incite behavioral changes in prey that lead to community-wide impacts on productivity, biodiversity, and nutrient cycling. The paucity of experimental manipulations, however, has contributed to controversy over the strength of this pathway in wide-ranging vertebrate systems. We investigated whether simulated gray wolf ( Canis lupus ) presence can induce behaviorally-mediated trophic cascades, specifically, whether the ‘fear’ of wolf olfactory cues alone can change deer foraging behavior in ways that affect plants and soils. Wolves were recently removed from the Cedar Creek Ecosystem Science Reserve (Minnesota, USA), such that consumptively mediated predator effects were negligible. At 32 experimental plots, we crossed two nested treatments: wolf urine application and herbivore exclosures. We deployed camera traps to quantify how white-tailed deer ( Odocoileus virginianus ) adjusted their spatiotemporal habitat use, foraging, and vigilance in response to wolf cues and how these behavioral changes affected plant productivity, plant communities, and soil nutrients. Weekly applications of wolf urine significantly altered deer behavior, but deer responses did not cascade to affect plant or soil properties. Deer substantially reduced crepuscular activity at wolf-simulated sites compared to control locations. As wolves in this area predominantly hunted during mornings and evenings, this response potentially allows deer to maximize landscape use by accessing dangerous areas when temporal threat is low. Our experiment suggests that prey may be sensitive to ‘dynamic’ predation risk that is structured across both space and time and, consequentially, prey use of risky areas during safe times may attenuate behaviorally-mediated trophic cascades at the predator–prey interface.

Minnesota↗
USGS2021

The importance of wilderness to wolf (Canis lupus) survival and cause-specific mortality over 50 years

We assessed the relative importance of wilderness to gray wolf (Canis lupus) population dynamics over 50 years in a population that 1) was long extant (i.e., not reintroduced or recolonized), 2) was not subject to harvest in our study area until recently, and 3) used both wilderness and adjacent, mainly public, non-wilderness. We analyzed the survival of radiocollared wolves (n = 756 collared-wolf tenures) during 1968–2018 in the Superior National Forest, Minnesota, USA, including the Boundary Waters Canoe Area Wilderness. Over 50 years, adult annual survival was 78%. Wolves captured in wilderness tended to exhibit higher survival than those captured in nonwilderness, but the difference was more pronounced during harvest years and post-harvest years when wilderness wolf survival remained relatively high and non-wilderness wolf survival dropped (relative to pre-harvest). During Nov–Apr of pre-harvest years for adults, the natural mortality rate was similar for non-wilderness wolves and wilderness wolves (both 6%), but the anthropogenic mortality rate was higher for non-wilderness wolves than wilderness wolves (7% versus 1%), as was the illegal mortality rate (5% versus 1%). During Nov–Apr of preharvest years, wilderness wolves were less likely to die than non-wilderness wolves (p = 0.042; hazard ratio = 0.59), pups were more likely to die than adults (p = 0.002; hazard ratio = 1.84), and males were less likely to die than females (p = 0.053; hazard ratio = 0.73). Our long-term wolf survival, cause-specific mortality, and hazard results will inform management agencies whenever wolves are delisted, and jurisdiction for them passes to states.

Minnesota↗
USGS2021

The enigma of the Předmostí protodogs. A comment on Prassack et al. 2020

Prassack et al. (2020) analyzed dental microwear in a sample of canids from the Gravettian site of Předmostí that had been identified as either Paleolithic dogs or Pleistocene wolves ( n = 10 in each group), accepting that the morphological differences between the groups validly distinguished the (self-domesticating) protodogs from wolves. The authors then concluded that differences in one m2 microwear pattern separated those groups and indicated enhanced anthropogenic based durophagy in the putative protodogs. The study also inferred protodog diets from another isotope study.

Journal of Archaeological Science↗
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↗
USGS2020

Unexplained patterns of grey wolf Canis lupus natal dispersal

Natal dispersal (movement from the site of birth to the site of reproduction) is a pervasive but highly varied characteristic of life forms. Thus, understanding it in any species informs many aspects of biology, but studying it in most species is difficult. In the grey wolf Canis lupus , natal dispersal has been well studied. Maturing members of both sexes generally leave their natal packs, pair with opposite‐sex dispersers from other packs, near or far, select a territory, and produce their own offspring. However, three movement patterns of some natal‐dispersing wolves remain unexplained: 1) long‐distance dispersal when potential mates seem nearby, 2) round‐trip travels from their natal packs for varying periods and distances, also called extraterritorial movements, and often not resulting in pairing, and 3) coincidental dispersal by individual wolves from a given area in the same basic directions and over the same long distances. This perspective article documents and discusses these unexplained dispersal patterns, suggests possible explanations, and calls for additional research to understand them more clearly.

Mammal Review↗
USGS2020

Seasonal cycles in hematology and body mass in free-ranging gray wolves (Canis lupus) from northeastern Minnesota, USA

Studies of captive gray wolves ( Canis lupus ) showed seasonal cycles in hematologic values and female body mass. We used a remotely controlled recapture collar to determine whether nine female and five male free-ranging wolves handled four to 17 times in NE Minnesota, US showed similar cycles. Hematocrit, hemoglobin, red blood cell count, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and body mass increased from summer toward a winter peak and then decreased again toward summer. Several hematologic values differed considerably from those of captive wolves, and the ranges in free-ranging wolves were much greater than those of captives.

Minnesota↗
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↗
USGS2019

Do Indigenous American Peoples’ stories inform the study of dog domestication?

I discuss the article “Relationships Between Indigenous American Peoples and Wolves 1: Wolves as Teachers and Guides” (Fogg et al. 2015) and the book “The First Domestication: How Wolves and Humans Coevolved” (Pierotti and Fogg 2017). The article proposed that published stories about interactions between indigenous American peoples and wolves ( Canis lupus ) provide insight into wolf-human relationships as humans began domesticating wolves. In the book, the authors offer a theory of how wolves and humans coevolved by building on the information in the article and the authors’ long experience with captive and pet wolves, wolf-dog hybrids, and dogs. I (1) present arguments and evidence that question the value of indigenous American stories for drawing conclusions about the relationship between early humans and wolves 14,000 yrs BP; (2) demonstrate how indigenous American stories contradict documented information about wolf biology, behavior, and known interactions with humans; and (3) point out important information not considered by the authors about wolf attacks on humans and the importance of rabies in the wolf-human relationship.

Ethnobiological Letters↗
USGS2019

Foreword

No abstract available.

Idaho, Montana, Wyoming↗