Type:Text

Subject:Aquatic nuisance species
ANS
Zebra mussels
Quagga mussels

Description:The Colorado Zebra/Quagga Mussel Management Plan (ZQM Plan) outlines a statewide collaborative effort to detect, contain, and substantially reduce the risk of the spread and further infestation by zebra/quagga mussels in Colorado. The Plan is coordinated by the Colorado Division of Wildlife (CDOW) as part of the State Aquatic Nuisance Species (ANS) Program. The Plan’s primary components are early detection and rapid response, containment, prevention and education/outreach. [show more]

Type:Text

Subject:Camera trap
Idaho
Montana
Occupancy
Sampling rare species
Washington
Wolverine
Wyoming

Description:In the western United States, wolverines (Gulo gulo) typically occupy high-elevation habitats. Because wolverine populations occur in vast, remote areas across multiple states, biologists have an imperfect understanding of this species' current distribution and population status. The historical extirpation of the wolverine, a subsequent period of recovery, and the lack of a coordinated monitoring program in the western United States to determine their current distribution further complicate understanding of their population status. We sought to define the limits to the current distribution, identify potential gaps in distribution, and provide a baseline dataset for future monitoring and analysis of factors contributing to changes in distribution of wolverines across 4 western states. We used remotely triggered camera stations and hair snares to detect wolverines across randomly selected 15-km × 15-km cells in Idaho, Montana, Washington, and Wyoming, USA, during winters 2016 and 2017. We used spatial occupancy models to examine patterns in wolverine distribution. We also examined the influence of proportion of the cell containing predicted wolverine habitat, human-modified land, and green vegetation, and area of the cluster of contiguous sampling cells. We sampled 183 (28.9%) of 633 cells that comprised a suspected wolverine range in these 4 states and we detected wolverines in 59 (32.2%) of these 183 sampled cells. We estimated that 268 cells (42.3%; 95% CI = 182–347) of the 633 cells were used by wolverines. Proportion of the cell containing modeled wolverine habitat was weakly positively correlated with wolverine occupancy, but no other covariates examined were correlated with wolverine occupancy. Occupancy rates (ψ) were highest in the Northern Continental Divide Ecosystem (ψ range = 0.8–1), intermediate in the Cascades and Central Mountains of Idaho (ψ range = 0.4–0.6), and lower in the Greater Yellowstone Ecosystem (ψ range = 0.1–0.3). We provide baseline data for future surveys of wolverine along with a design and protocol to conduct those surveys.  [show more]

Type:Text

Subject:Prey selection
Wolf
Elk
Bison

Description:What a predator eats when given choices, and the subsequent effects of this behavior on ecosystem stability, has long been a topic of interest for ecologists.  href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/prey-selection" title="Learn more about Prey Selection from ScienceDirect's AI-generated Topic Pages" class="topic-link" target="_blank" rel="noreferrer noopener">Prey selection is influenced by the absolute and relative abundances of prey types, the life history characteristics of predators and prey, and the attributes of the environment in which these interactions occur. Strong preference by a predator for a particular prey type can lead to ecosystem instability, while prey switching can lessen predation effects on the less abundant prey and enhance system stability. Evaluating prey selection in large mammal systems is difficult due to the broad spatial and temporal scales at which these predatory interactions occur, and investigations, particularly with wolf-ungulate systems, typically involve only the primary prey. Multiple prey species characterize most large mammal predator-prey systems, therefore research into predator-multiple prey dynamics has the potential to yield important ecological insights. We studied winter prey selection during 1996–1997 through 2006–2007 in a newly established wolf-elk-bison system where prey differed substantially in their vulnerability to wolf (Canis lupus) predation and wolves preyed primarily on elk (Cervus elaphus) but also used bison (Bison bison) to varying degrees within and among winters and packs. We analyzed the relative influences of prey abundance, predator abundance, and environmental variables on the selection of prey species and age classes and evaluated whether wolves exhibited prey switching from elk to bison. [show more]

Type:Text

Subject:Predator–prey interactions
Prey selection
Wolf
Elk
Bison

Description:The ability of predators to successfully capture and kill prey is affected by the abundance and diversity of the prey assemblage, and such variation is a fundamental driver of ecosystem dynamics because per capita consumption rate strongly influences the stability and strength of community interactions. Descriptions of predatory behavior in this context typically include the functional response, specifically the kill rate of a predator as a function of prey density. Thus, a major objective in studying predator–prey interactions is to evaluate the strength of the numerous factors related to the kill rate of a predator, and to subsequently determine the forms of its functional response in natural systems because different forms have different consequences for ecosystem dynamics. Recent controversies over the nature of predation focus on the respective roles of prey and predator abundance in affecting the functional response. However, resolution requires more direct measures of kill rates in natural systems. We estimated wolf (Canis lupus) kill rates in a tractable and newly established wolf–elk (Cervus elaphus)–bison (Bison bison) system in the Madison headwaters area of Yellowstone National Park during winters 1998–1999 to 2006–2007 to document the transition from over seven decades without wolves to a well-established top predator population. Wolf abundance, distribution, and prey selection varied during the study, concurrent with variations in the demography, distribution, and behavior of elk and bison. These dynamics enabled us to evaluate factors influencing variations in wolf kill rates and the forms of their functional response. [show more]

Type:Text

Subject:Backcountry skiing
Colorado
Dispersed recreation
Functional response
Habitat selection
Heliskiing
<em>Lynx canadensis</em>
Outdoor recreation
Resource-selection functions
Snowmobiling
Winter recreation

Description:Outdoor recreationists are important advocates for wildlife on public lands. However, balancing potential impacts associated with increased human disturbance with the conservation of sensitive species is a central issue facing ecologists and land managers alike, especially for dispersed winter recreation due to its disproportionate impact to wildlife. We studied how dispersed winter recreation (outside developed ski areas) impacted a reintroduced meso-carnivore, Canada lynx (Lynx canadensis), at the southern periphery of the species’ range in the southern Rocky Mountains. On a voluntary basis, we distributed global positioning system (GPS) units to winter recreationists and documented 2143 spatial movement tracks of recreationists engaged in motorized and nonmotorized winter sports for a total cumulative distance of 56,000 km from 2010 to 2013. We also deployed GPS radio collars on adult Canada lynx that were resident in the mountainous topography that attracted high levels of dispersed winter recreation. We documented that resource-selection models (RSFs) for Canada lynx were significantly improved when selection patterns of winter recreationists were included in best-performing models. Canada lynx and winter recreationists partitioned environmental gradients in ways that reduced the potential for recreation-related disturbance. Although the inclusion of recreation improved the RSF model for Canada lynx, environmental covariates explained most variation in resource use. The environmental gradients that most separated areas selected by Canada lynx from those used by recreationists were forest canopy closure, road density, and slope. Canada lynx also exhibited a functional response of increased avoidance of areas selected by motorized winter recreationists (snowmobiling off-trail, hybrid snowmobile) compared with either no functional response (hybrid ski) or selection for (backcountry skiing) areas suitable for nonmotorized winter recreation. We conclude with a discussion of implications associated with providing winter recreation balanced with the conservation of Canada lynx. [show more]

Type:Text

Subject:Canada lynx
Colorado
Diet
Hunting success
<em>Lepus americanus</em>
<em>Lynx canadensis</em>
Red squirrel
Refugia
Snowshoe hare
Stem density
<em>Tamiasciurus hudsonicus</em>

Description:Information regarding the diet of Canada lynx (Lynx canadensis) at the southernmost extent of its range is critical for managing the species under current and predicted climate conditions. Therefore, from 1999–2009, we investigated winter diet and hunting strategies of Canada lynx in Colorado, USA by tracking individuals in the snow to identify sites where lynx encountered and killed prey. Similar to other parts of lynx range, snowshoe hares (Lepus americanus) were the primary winter food in Colorado, especially when considering total biomass consumed. Red squirrels (Tamiasciurus hudsonicus) comprised the bulk of the remaining food items and were a substantial occurrence during several years, which is consistent with previous hypotheses regarding the diet of lynx in southerly populations. Lynx successfully captured snowshoe hares on 31% of attempts and red squirrels on 47% of attempts, similar to lynx in other regions. In contrast to other populations, the majority of chases of both prey species were initiated while actively hunting rather than by ambush and this behavior did not change through time. We found evidence for snowshoe hare refugia during winter; hunting success for hares peaked at sites with approximately 3,000 stems/ha, but was lower in more dense vegetation where hare densities were greater. Given this finding and the apparent importance of red squirrels as alternate prey, we suggest that management for lynx in the southern Rocky Mountains, USA, focus on maintenance of mature, uneven-aged Engelmann spruce (Picea engelmannii)-subalpine fir (Abies lasiocarpa) stands. Such stands naturally provide patches of dense and open habitats juxtaposed closely together that should simultaneously facilitate high hare densities (and refuge from predation) and accessibility to hares by lynx. Mature trees in such stands also provide abundant cone crops to sustain populations of red squirrels for use as alternate prey.  [show more]

Type:Text

Subject:Plague
<em>Yersinia pestis</em>
Colorado
<em>Puma concolor</em>
<em>Lynx rufus</em>
Zoonoses
Disease ecology

Description:Plague seroprevalence was estimated in populations of pumas and bobcats in the western United States. High levels of exposure in plague-endemic regions indicate the need to consider the ecology and pathobiology of plague in nondomestic felid hosts to better understand the role of these species in disease persistence and transmission. [show more]

Type:Text

Subject:Whitewater parks

Description:With over 30 whitewater parks (WWPs) either completed or in the planning phases, Colorado is the epicenter for WWP development in the United States. Although WWPs provide economic and recreational benefits for local communities (Hagenstad et al. 2000; Loomis and McTernan 2011), they may have unintended impacts on instream biota and stream functions, particularly when the hydraulic conditions formed by the WWP are different from those naturally found in the surrounding river. The impact of WWPs on habitat connectivity and instream habitat quality have been the focus of several recent studies. Although these studies have primarily focused on fish passage and habitat, impacts to aquatic insects and sediment transport may also occur at WWPs. [show more]

Type:Text

Subject:Whitewater parks

Description:Colorado Parks and Wildlife’s (CPW) statutory mission is to perpetuate the wildlife resources of the State, to provide a quality State Parks system, and to provide enjoyable and sustainable outdoor recreation opportunities that educate and inspire current and future generations to serve as strategic stewards of Colorado’s natural resources (C.R.S. § 33-9-101 (12) (b)). As CPW is responsible for the management and conservation of aquatic resources within the State, we are asked to review projects that may affect aquatic habitats or populations. Specifically, CPW staff is often engaged by the Army Corps of Engineers (USACE) to review permit applications related to the design, construction, and monitoring of whitewater parks (WWPs) regulated under Section 404 of the Clean Water Act. WWP projects typically fall under the following permits:

• NWP 27 - Aquatic Habitat Restoration, Establishment, and Enhancement Activities
• IP - An individual, or standard permit, is issued when projects have more than minimal individual or cumulative impacts, are evaluated using additional environmental criteria, and involve a more comprehensive public interest review.

[show more]

Subject:Whitewater park projects

Description:A guidance document for reviewing whitewater park projects