Steve Windels

• PhD
• Researcher at National Park Service

Tail-mounted transmitters have been used successfully in temperate regions of North America and Europe but have not been tested in more northern parts of American beaver Castor canadensis range. We deployed 63 tail-mounted transmitters on adult beavers in Voyageurs National Park, Minnesota (USA; 48°30′N, 92°50′W), at the southern edge of the boreal...

One key assumption often inferred with using radio-equipped individuals is that the transmitter has no effect on the metric of interest. To evaluate this assumption, we used a known fate model to assess the effect of transmitter type (i.e. tail-mounted or peritoneal implant) on short-term (one year) survival and a joint live--dead recovery model an...

Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group‐level processes such as subgroup formation and fission–fusion dynamics. Although critical t...

Moose (Alces alces; mooz [singular], moozoog [plural] in Anishinaabemowin, Ojibwe language) are an important species to many Indigenous rights-holders and stakeholders throughout their circumpolar range. Management of moose can often lead to conflict when various perspectives of Indigenous nations are not recognized or appreciated. During the 55th

The moose (Alces alces; mooz in Anishinaabemowin, Ojibwe language) population has recently declined in Minnesota, USA, and gray wolf (Canis lupus; ma'iingan) predation is likely a contributing factor. We analyzed diet composition of gray wolves in northeastern Minnesota during 2011-2013 to evaluate the importance of moose as prey and seasonal and r...

Cooperative hunting can confer fitness benefits by increasing foraging efficiency. We documented a breeding pair of wolves in the Greater Voyageurs Ecosystem of Minnesota, USA that appeared to periodically use cooperative ambushing to hunt beavers. The breeding pair primarily chose to wait-in-ambush close to one another (< 65 m) but on different be...

Humans are increasingly recognized as important players in predator–prey dynamics by modifying landscapes. This trend has been well‐documented for large mammal communities in North American boreal forests: logging creates early seral forests that benefit ungulates such as white‐tailed deer (Odocoileus virginianus), while the combination of infrastr...

New insights into the changing human attitudes towards wild nature through the depiction of wolves in human culture and heritage.

Recovering species are not returning to the same environments or communities from which they disappeared. Conservation researchers and practitioners are thus faced with additional challenges in ensuring species resilience in these rapidly changing ecosystems. Assessing the resilience of species in these novel systems can still be guided by species’...

Through global positioning system (GPS) collar locations, remote cameras, field observations and the first wild wolf to be GPS-collared with a camera collar, we describe when, where and how wolves fish in a freshwater ecosystem. From 2017 to 2021, we recorded more than 10 wolves (Canis lupus) hunting fish during the spring spawning season in northe...

Transboundary movement of wildlife results in some of the most complicated and unresolved wildlife management issues across the globe. Depending on the location and managing agency, gray wolf (Canis lupus) management in the US ranges from preservation to limited hunting to population reduction. Most wildlife studies focus on population size and gro...

One of the most common and ubiquitous methods to age mammals is by counting the cementum annuli in molars, premolars, incisors, or canines. Despite the ubiquity and perceived simplicity of the method, cementum annuli analysis can be time-consuming, expensive, inaccurate, and imprecise, and require specialized equipment. Using beavers (Castor canade...

Given recent and abrupt declines in the abundance of moose (Alces alces) throughout parts of Minnesota and elsewhere in North America, accurately estimating statewide population trends and demographic parameters is a high priority for their continued management and conservation. Statistical population reconstruction using integrated population mode...

Given recent and abrupt declines in the abundance of moose (Alces alces) throughout parts of Minnesota, accurately estimating statewide population trends and demographic parameters is a high priority for their continued management and conservation. Statistical population reconstruction using integrated population models provides a flexible framewor...

Like many ecological processes, natural disturbances exhibit scale‐dependent dynamics that are largely a function of the magnitude, frequency and scale at which they are assessed. Ecosystem engineers create patch‐scale disturbances that affect ecological processes, yet we know little about how these effects scale across space or vary through time....

Muskrat (Ondatra zibethicus) populations show long-term and widespread declines across North America, necessitating research into potential mechanistic explanations, including population health. Previous research established reference hematology values, a proxy of individual health, of muskrats occurring in highly modified ecosystems. However, our...

Comprehensive knowledge of ambush behavior requires an understanding of where a predator expects prey to be, which is generally un-knowable because ambush predators often hunt mobile prey that exhibit complex, irregular, or inconspicuous movements. Wolves (Canis lupus) are primarily cursorial predators, but they use ambush strategies to hunt beaver...

Intraspecific competition plays an important role for territory acquisition and occupancy, in turn affecting individual fitness. Thus, understanding the drivers of intraspecific aggression can increase our understanding of population dynamics. Here, we investigated intraspecific aggression in Eurasian (Castor fiber) and North American (Castor canad...

Gray wolves are a premier example of how predators can transform ecosystems through trophic cascades. However , whether wolves change ecosystems as drastically as previously suggested has been increasingly questioned. We demonstrate how wolves alter wetland creation and recolonization by killing dispersing beavers. Beavers are ecosystem engineers t...

ContextInterspecific competition can limit species distributions unless competitors partition niche space to enable coexistence. Landscape heterogeneity can facilitate niche partitioning and enable coexistence, but land-use change is restructuring terrestrial ecosystems globally with unknown consequences for species interactions.Objectives We teste...

Over the past two decades, there have been numerous calls to make ecology a more predictive science through direct empirical assessments of ecological models and predictions. While the widespread use of model selection using information criteria has pushed ecology toward placing a higher emphasis on prediction, few attempts have been made to valida...

Waterborne transmission of Toxoplasma gondii is assumed to be enhanced in areas with human-altered landscapes (e.g., urbanization, agriculture) and increased populations of non-native domestic and feral cats (Felis catus). However, little is known concerning T. gondii exposure risks in more natural watersheds (e.g., reduced human footprint, no dome...

Wolves (Canis lupus) primarily provision pups by catching mammalian prey and bringing remains of the carcass to the pups at a den or rendezvous site via their mouths or stomach. In August 2017, we observed an adult wolf regurgitating wild blueberries (Vaccinium spp.) to pups at a rendezvous site in the Greater Voyageurs Ecosystem, Minnesota, USA, w...

Landscape configuration and composition can influence the spatial distribution of species. Cross-scale interactions may exist when multiscale effects interplay to shape species’ distribution patterns. Objectives We investigated how the spatial distribution of a semiaquatic mammal, muskrat (Ondatra zibethicus), is influenced by local-scale resource...

In 2018, we documented 2 grey wolves (Canis lupus) from the Greater Voyageurs Ecosystem, Minnesota that dispersed >300 km north individually but exhibited strikingly similar dispersal patterns. These individuals eventually interacted with one another several months after dispersing. Though the probability of this occurring randomly appears incredib...

Pekania pennanti (Fisher) is a generalist mesocarnivore that has been documented to prey on a diversity of mammals, but there have been no previous documented incidents of a Fisher hunting and killing a semi-aquatic mammal. Here, we report a first-hand observation and DNA evidence of a Fisher hunting and killing an Ondatra zibethicus (Muskrat) from...

The recovery of piscivorous birds around the world is touted as one of the great conservation successes of the 21st century, but for some species, this success was short‐lived. Bald eagles, ospreys and great blue herons began repatriating Voyageurs National Park, USA, in the mid‐20th century. However, after 1990, only eagles continued their recover...

Locating wolf (Canis lupus) homesites is valuable for understanding the foraging behavior, population dynamics, and reproductive ecology of wolves during summer. During this period wolf pack members (adults and pups) readily respond to simulated wolf howls (i.e., howl surveys), which allows researchers to estimate the location of the homesite via t...

R code for statistical analysis

Statistical analysis for howl survey and homesite data

Howl survey data Howl survey data from Voyageurs National Park from 2015–2017.

Within the western Great Lakes (WGL) U.S. region (Michigan, Minnesota, Wisconsin), the ecological impacts that North American Beavers Castor canadensis (hereafter referred to as Beaver) have on cold‐water streams are generally considered to negatively affect salmonid populations where the two taxa interact. Beavers are common and widespread within...

Predators directly impact prey populations through lethal encounters, but understanding nonlethal, indirect effects is also critical because foraging animals often face trade‐offs between predator avoidance and energy intake. Quantifying these indirect effects can be difficult even when it is possible to monitor individuals that regularly interact....

We present a novel approach for modelling and mapping habitat suitability from species presence-only data that is useful for ecosystem and species monitoring. The approach models the relationship between species habitat suitability and environment conditions using probability distributions of species presence over environmental factors. Resource av...

Over the past decade, there has been much debating about whether wolves possess high-order cognitive abilities that facilitate deliberate or cooperative hunting strategies such as ambush to capture prey. Beavers can be important alternate or primary prey for wolves in North America and Europe, but no observations of wolves hunting and killing beave...

In April–May 2017 we documented GPS-collared wolves (V034 and V046) from the same pack in northern Minnesota responding to a spring fish (northern pike and presumably white suckers) run, which to our knowledge is the first description of wolves outside of a coastal marine environment using fish as a seasonal food source. During this period, we oppo...

Few accounts exist of Gray Wolves (Canis lupus) killing small sympatric mammalian predators. In January 2017, we observed a River Otter (Lontra canadensis) that had been killed by wolves on the ice in Voyageurs National Park, Minnesota. This is one of only a few documented instances of wolves killing otters.

Predator–prey relationships can have wide‐ranging ecological and landscape‐level effects. Knowledge of these relationships is therefore crucial to understanding how these systems function and how changes in predator–prey communities affect these systems. Grey wolves Canis lupus can be significant predators of beavers Castor spp., and conversely, be...

Wolves (Canis lupus) can be primary predators of beavers (Castor canadensis), but little is known about wolf-beaver dynamics. We identified kills from 1 wolf (V009) of the Ash River Pack in Voyageurs National Park from 1 April to 5 November 2015 to provide direct estimates of wolf pack kill and predation rates of beavers. We documented 12 beaver ki...

Threatened species are managed using diverse conservation tactics implemented at multiple scales ranging from protecting individuals, to populations, to entire species. Individual protection strives to promote recovery at the population‐ or species‐level, although this is seldom evaluated. After decades of widespread declines, bald eagles, Haliaeet...

Wolves (Canis lupus) are opportunistic predators and will capitalize on available abundant food sources. However, wolf diet has primarily been examined at monthly, seasonal, or annual scales, which can obscure short-term responses to available food. We examined weekly wolf diet from late June to early October by collecting scats from a single wolf...

Rule curves dictating target water levels for management have been implemented in several water bodies in North America over the last 70 years or more. Anthropogenic alterations of water levels are known to affect several components of wetland ecosystems. Evaluating the influence of rule curves on biological components with simple performance indic...

[This corrects the article DOI: 10.1093/cz/zox047.][This corrects the article DOI: 10.1093/cz/zox047.].

Beavers are ecological engineers but also keystone species, whose presence in the boreal forest is critical for creating and modifying habitat for a myriad of other species. Beaver impoundments are used extensively by moose and white-tailed deer for feeding, cooling, predator avoidance, and relief from biting insects. Gray wolves focus use on beave...

Populations inhabiting the bioclimatic edges of a species’ geographic range face an increasing amount of stress from alterations to their environment associated with climate change. Moose are large-bodied ungulates that are sensitive to heat stress and have exhibited population declines and range contractions along their southern geographic extent....

Wolf (Canis lupus L., 1758) diet is commonly estimated via scat analysis. Several researchers have concluded that scat collection method can bias diet estimates, but none of these studies properly accounted for interpack, age class, and temporal variability, all of which could bias diet estimates. We tested whether different scat collection methods...

How organisms respond to and are influenced by temperature is one of the most fundamental aspects of ecology. Temperature affects animal physiology, behavior, survival, and reproduction. At broader spatial and temporal scales, temperature affects animal distributions, speciation, and evolution. Although entire textbooks have been devoted to how tem...

Moose are at the southern edge of their range in Minnesota, where populations have experienced dramatic declines over the last 10 to 20 years. Concern for the status of moose in Voyageurs National Park resulted in the establishment of a monitoring program in 2009 that includes an annual estimate of the moose population in winter. The 2017 survey wa...

Oral papillomatosis was diagnosed in a gray wolf ( Canis lupus ) with sarcoptic mange from Minnesota, USA found dead in February 2015. Intranuclear inclusion bodies were evident histologically, and papillomaviral antigens were confirmed using immunohistochemistry. Sequencing of the L1 papillomavirus gene showed closest similarity to Lambdapapilloma...

White-tailed deer (Odocoileus virginianus) are an important component of southern boreal ecosystems, including those within and adjacent to Voyageurs National Park (VOYA), Minnesota. Voyageurs National Park staff has employed aerial and pellet-based methods of deer population monitoring for several periods from 1989 to present. Our objective for th...

We tested serum samples from 387 free-ranging wolves ( Canis lupus ) from 2007 to 2013 for exposure to eight canid pathogens to establish baseline data on disease prevalence and spatial distribution in Minnesota's wolf population. We found high exposure to canine adenoviruses 1 and 2 (88% adults, 45% pups), canine parvovirus (82% adults, 24% pups),...

Gray wolves (Canis lupus) consume berries and other wild fruits seasonally when available or abundant. However, a method to convert percent frequency of occurrence or percent volume of berries in wolf scats to percent biomass has not yet been developed. We used estimates of the average number of blueberry (Vaccinium spp.) seeds in 10 individual wol...

Beavers (Castor canadensis) can be a significant prey item for wolves (Canis lupus) in boreal ecosystems due to their abundance and vulnerability on land. How wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. We inferred how wolves hunt beavers by identifying kill sites using clusters of l...

Individual Descriptions of Kill Sites. (PDF)

Locations of Individual Kill Sites. (KMZ)

Context. Animals selectively use landscapes to meet their energetic needs, and trade-offs in habitat use may depend on availability and environmental conditions. For example, habitat selection at high temperatures may favor thermal cover at the cost of reduced foraging efficiency under consistently warm conditions. Objective. Our objective was to...

Ungulates that are adapted to cold climates may use bed sites as thermal refuges during summer. At the southern edge of their distribution moose Alces alces often encounter ambient summer temperatures above their upper critical temperature. Summer is also when moose increase food consumption and metabolism, which increases heat generation that must...

Most investigations of the environmental effects of mercury (Hg) have focused on aquatic food webs that include piscivorous fish or wildlife. However, recent investigations have shown that other species, including passerine songbirds, may also be at risk from exposure to methylmercury (MeHg). We quantified Hg concentrations in eggs of two species o...

Moose (Alces alces) employ physiological and behavioral mechanisms to enable them to dissipate excess heat when ambient temperature is above the upper critical temperature of their thermoneutral zone. In this note, we describe 2 cases where GPS radio-collared female moose modified summer bed sites as a potential thermoregulatory response to high te...

Beaver ponds and beaver-impounded vegetation are indicators of past or present beaver activity that can be detected from aerial photography. A method to quantitatively relate these beaver works with the density of active beaver colonies could benefit beaver management, particularly in areas lacking beaver population data. We compared historical map...

SUMMARY Parasites that primarily infect white-tailed deer (Odocoileus virginianus), such as liver flukes (Fascioloides magna) and meningeal worm (Parelaphostrongylus tenuis), can cause morbidity and mortality when incidentally infecting moose (Alces alces). Ecological factors are expected to influence spatial variation in infection risk by affectin...

External marking of American beavers (Castor canadensis) is essential to studies of population dynamics and behavior of individuals. Application of metal ear tags is a common method used to mark beavers but rates and causes of ear-tag loss have been insufficiently documented. I live-trapped and tagged 627 beavers in Voyageurs National Park, Minneso...

Voyageurs National Park (VNP) has a stable population of about 40–50 moose (Alces alces). Recent declines in moose abundance in adjacent areas in northern Minnesota raise concerns about the long-term viability of moose in VNP. The parasitic nematode Parelaphostrongylus tenuis has been documented in moose in VNP and has been implicated in moose decl...

Moose (Alces alces) respond to warm temperatures through both physiological and behavioral mechanisms. Moose can reduce heat load via habitat selection when spatial and temporal variation exists within the thermal environment. We recorded operative temperatures (T o) throughout the Kabetogama Peninsula of Voyageurs National Park, Minnesota for 1 ye...

生境适宜度制图能提供动物适宜生境的空间分布信息,对野生动物种群管理、保护地规划等非常重要。 生境适宜度制图的关键是构建生境适宜度模型(habitat suitability model, HSM),只基于动物出现位置数据构建 HSM 的方法在实践中得到了非常广泛的应用。 然而现有的只基于动物出现位置数据构建 HSM 的方法还不能很好地直接表达动物生境适宜度和环境因子之间具有生态学意义的数量关系,因此也就不能很好地体现环境因子对动物生境利用的生态学作用。 提出了一种基于核密度估计构建 HSM 的方法,在地理信息系统技术支持下,通过运用核密度估计从代表性的动物出现位置数据中估计出动物出现对各个环境因子的概率密度函数来直接表达生境适宜度与各个环境因子之间的数量关系,以体现环境因子对动物生境利用的生...

Mounting evidence sug-gests that a European invader is hybridizing with native cattails in three national parks in the Great Lakes region. This is posing a threat to native biodiversity and causing a "hybrid swarm" into areas where cattails (Typha spp.) have never been seen. The invasive narrowleaf cattail (T. angustifolia), which has been spreadin...

Water-level management is widespread and illustrates how contemporary climate can interact directly and indirectly with numerous biological and abiotic factors to influence reproductive success of wildlife species. We studied common loons, an iconic waterbird sensitive to timing and magnitude of water-level changes during the breeding season, using...

Background/Question/Methods Recent scientific and anecdotal evidence suggests that warming temperatures may play a role in the decline of moose (Alces alces) populations in Minnesota. Moose may respond to warm temperatures by physiological and behavioral mechanisms (e.g., panting or selection of cool habitats). The ability of habitat selection to...

Forage availability can affect body condition and reproduction in wildlife. We used terrestrial and aquatic vegetation sampling, stable isotope analysis, and livetrapping to investigate the influence of estimated forage biomass on diet, body condition, and reproduction in American beavers (Castor canadensis) in the Namakan Reservoir, Voyageurs Nati...

We evaluated the influence of sex and reproductive condition on seasonal distribution and movement patterns of Lake Sturgeon (Acipenser fulvescens) in Namakan Reservoir, Minnesota–Ontario. Blood samples were collected from 133 Lake Sturgeon prior to spawning and plasma concentrations of testosterone and estradiol-17ß were analyzed using radioimmuno...

Canada yew (Taxus canadensis) is a clonal shrub that forms discrete patches and was formerly an important component of forest understories in much of northeastern North America. Following Euro-American settlement, Canada yew has been extirpated or reduced in abundance throughout much of its former range, particularly in the USA; winter browsing by...

American beavers (Castor canadensis) forage on various aquatic and terrestrial plant species. We used stable isotope analysis of carbon (C) and nitrogen (N) to estimate source contributions of seasonal assimilated beaver diets in Voyageurs National Park, Minnesota, from Apr. 2007 to Nov. 2008. Mean (±95% confidence interval) annual beaver diets wer...

Voyageurs National Park (VNP) is within the historical distribution of Canada lynx (Lynx canadensis), a federally threatened species. Sightings of lynx in and near VNP have existed since the 1970s, and three recent sightings have been confirmed with DNA analysis. However, population status and habitat suitability for lynx in VNP are unknown. We use...

The Namakan River and Reservoir system lies on the boundary of Canada and the United States. This system is an important area for lake sturgeon, a species listed as special concern in both countries. A total of 60 adult lake sturgeon were caught and implanted with acoustic transmitters in May of 2007 by the Ontario Ministry of Natural Resources (Ca...

Double-crested cormorant populations have rebounded dramatically throughout the Great Lakes region over the last 40 years since DDT and other contaminants were banned. In many areas, cormorants are actively managed to reduce conflicts with human uses. Bald eagles have also experienced a meteoric return throughout much of their range in the Great La...

Quantified were the age, growth, mortality and reproductive structure of lake sturgeon (Acipenser fulvescens) collected in the US and Canadian waters of the Namakan Reservoir. The hypotheses were tested that (i) age and growth of lake sturgeon in the Namakan Reservoir would differ by sex and reproductive stage of maturity, and (ii) that the relativ...

Herbivores must balance energy needs with avoiding risks, using various cues to assess predation risk. The American beaver (Castor canadensis) is a semi-aquatic herbivore vulnerable to predation on land by wolves (Canis lupis). We tested the use of wolf urine as a potential tool to reduce human–beaver confl icts. We used infrared cameras to monitor...

Carrying capacity estimates based on digestible protein (DP) and energy (DE) are useful in comparing effects of land management practices or the ability of different vegetation communities to support herbivores. Plant secondary compounds that negatively affect forage quality would be expected to change nutritionally based estimates of carrying capa...