Type:Fact Sheet

Subject:Aquatic nuisance species
ANS
Boating
Inspections
Zebra mussels
Quagga mussels

Description:The State Aquatic Nuisance Species (ANS) Act was signed into law May 2008. The Act defines ANS as exotic or nonnative aquatic wildlife or any plant species that have been determined to pose a significant threat to the aquatic resources or water infrastructure of the state. The Parks Board passed regulations required by the Act on February 20, 2009 and updated them since that time. The regulations require mandatory watercraft inspection, and if necessary, decontamination of all boats coming from out of state, leaving waters with known ANS and boats entering high-risk waters where inspections are required by the managing entity. The focus of the program is to prevent zebra and quagga mussels and other ANS from infesting Colorado’s water resources and threatening our water storage and distribution systems for municipal, industrial and agricultural use. The Colorado ANS Program is highly effective and a model which other states across the nation are learning from. [show more]

Type:Text

Subject:Aquatic nuisance species
ANS
Boating

Description:Some wakeboard boats, ski boats and sailboats have ballast tanks which are filled with water to stabilize the boat and allow them to ride lower in the water. Many ballast tanks can’t be visually checked, and many cannot be fully drained.

Type:Article

Subject:Decision-making
Forest landowners
Behavior change model

Landowner behavior

Description:Approximately 1.2 million family forest landowners (FFOs) manage nearly 37 million acres of forestland in five New England states. This means that efforts to sustain and conserve forests in the region are contingent upon short- and long-term management decisions of these owners. We applied the transtheoretical model of behavior change to understand which activities and behaviors FFOs have pursued in relation to forest legacy planning. We conducted a regional mail survey of 2500 FFOs across Maine, Massachusetts, Vermont, and New York. Findings indicate that the majority of FFOs are preparing for or are currently engaging in beginning-level legacy planning decisions while few are thinking about nor planning for more advanced-level decisions. Findings from three stepwise multiple regression models also provide support for predicting a substantive amount of variance in FFOs’ decisions to engage in beginning-level and conservation-oriented planning decisions. [show more]

Type:Article

Subject:Black bear
Human-bear conflict
Bear-resistant containers
Public perception

Description:Human-black bear conflicts within urban environments have been increasing throughout North America, becoming a high priority management issue. The main factor influencing these conflicts is black bears foraging on anthropogenic foods within areas of human development, primarily on residential garbage. Wildlife professionals have advocated for increased bear-proofing measures to decrease the accessibility of garbage to bears, but little research has been conducted to empirically test the effectiveness of this approach for reducing conflicts. Between 2011 and 2016, we conducted a before-after-control-impact experiment in Durango, Colorado where we distributed 1,110 bear-resistant trash containers, enhanced education, and increased enforcement to residents in 2 treatment areas, and monitored 2 paired control areas. We examined the ecological and social outcomes of this experiment, assessing whether bear-resistant containers were effective at reducing conflicts; the level of public compliance (i.e., properly locking away garbage) needed to reduce conflicts; whether the effectiveness of bear-resistant containers increased over time; and if the distribution of bear-resistant containers changed residents’ attitudes about bear management, support for ordinances that require bear-proofing, or perceptions of their future risk of garbage-related conflicts. After the bear-resistant containers were deployed, trash-related conflicts (i.e., observations of strewn trash) were 60% lower in treatment areas than control areas, resident compliance with local wildlife ordinances (properly locking away trash) was 39% higher in treatment areas than control areas, and the effectiveness of the new containers was immediate. Conflicts declined as resident compliance with wildlife ordinances increased to approximately 60% (by using a bear-resistant container or locking trash in a secure location), with minor additional declines in conflicts at higher levels of compliance. In addition to these ecological benefits, public mail surveys demonstrated that the deployment of bear-resistant containers was associated with increases in the perceived quality of bear management and support for ordinances that require bear-proofing, and declines in the perceived risk of future trash-related conflicts. Our results validate efforts by wildlife professionals and municipalities to reduce black bear access to human foods, and should encourage other entities of the merits of bear-proofing efforts for reducing human-bear conflicts and improving public attitudes about bears and their management. © 2018 The Wildlife Society. [show more]

Type:Text

Subject:Greater sage-grouse
<em>Centrocercus urophasianus</em>
Parachute-Piceance-Roan (PPR) region
Wildlife habitat improvement
Northwestern Colorado

Description:Greater sage-grouse (Centrocercus urophasianus) in the Parachute-Piceance-Roan (PPR) region of western Colorado face at least two major potential stressors: projected habitat loss from energy development and a long-term decline in habitat suitability associated with pinyon-juniper (PJ) encroachment. PJ removal may be a useful mitigation tool to offset potential habitat losses associated with energy development. Although PJ removal is commonly used to improve habitat for greater sage-grouse, no studies to date have quantified the timing or magnitude of how birds respond to treatments. Since 2008, Colorado Parks and Wildlife (CPW) has cooperated with industry and landowner partners to investigate the effectiveness of PJ removal for restoring sage-grouse habitat in the PPR. In fall 2008, I established nine “survey” study plots, arranged in three groups of three, with each group consisting of a sagebrush control plot, an untreated PJ control plot, and a PJ treatment plot. Treatments were completed on the three treatment plots in 2010 and 2011. [show more]

Type:Text

Subject:Elk
Predation (Biology)
Wolves

Description:Predator-prey models have traditionally been built on the assumption that neither predators nor prey are capable of learning or adapting behavior based on past interactions. As such, these models typically account for predation by forcing prey to experience a fixed level of predation risk. In order to develop species specific and more realistic models, the enemy-victim interaction behaviors of both predators and prey need to be studied. We quantified selection patterns for 2 fine scale behaviors of a recovering wolf population in Yellowstone National Park, Wyoming. Wolf spatial data were collected between November and May from 1998-1999 until 2001 -2002. Over four winters; 244 aerial locations, 522 ground based telemetry locations, 1,287 km of movement data from snow-tracking and the locations of 279 wolf kill sites were recorded. There was evidence that elk (Cervus elaphus) and bison (Bison bison) densities had a weak effect on the sites where wolves traveled and made kills. Wolf movements showed a strong selection for geothermal areas, meadows and areas in close proximity to edge. Proximity to edge and habitat class also had a strong influence on the locations where elk were most vulnerable to predation. There was little evidence that wolf kill sites differed from the places where wolves traveled, indicating that wolves selected to travel in areas where they were most successful at killing elk. Our results indicate that prey are more vulnerable to predators under certain conditions, predators are capable of selecting for these conditions, and as such, the notion of a fixed predation risk is largely inadequate. [show more]

Type:Article

Subject:Mule deer
Spatial heterogeneity
Temporal heterogeneity
Western Colorado
Climate change

Description:Understanding how spatial and temporal heterogeneity influence ecological processes forms a central challenge in ecology. Individual responses to heterogeneity shape population dynamics, therefore understanding these responses is central to sustainable population management. Emerging evidence has shown that herbivores track heterogeneity in nutritional quality of vegetation by responding to phenological differences in plants. We quantified the benefits mule deer (Odocoileus hemionus) accrue from accessing habitats with asynchronous plant phenology in northwest Colorado over 3 years. Our analysis examined both the direct physiological and indirect environmental effects of weather and vegetation phenology on mule deer winter body condition. We identified several important effects of annual weather patterns and topographical variables on vegetation phenology in the home ranges of mule deer. Crucially, temporal patterns of vegetation phenology were linked with differences in body condition, with deer tending to show poorer body condition in areas with less asynchronous vegetation green-up and later vegetation onset. The direct physiological effect of previous winter precipitation on mule deer body condition was much less important than the indirect effect mediated by vegetation phenology. Additionally, the influence of vegetation phenology on body fat was much stronger than that of overall vegetation productivity. In summary, changing annual weather patterns, particularly in relation to seasonal precipitation, have the potential to alter body condition of this important ungulate species during the critical winter period. This finding highlights the importance of maintaining large contiguous areas of spatially and temporally variable resources to allow animals to compensate behaviourally for changing climate-driven resource patterns. [show more]

Type:Fact Sheet

Subject:Waterfowl -- Diseases
Avian botulism
Birds

Description:Fact sheet on species affected by avian botulism in Colorado.

Type:Text

Subject:Ecology
Zoology
Biostatistics

Description:Point count surveys of birds are commonly used to provide indices of abundance or, in some cases, estimates of true abundance. The most common use of point counts is to provide an index of population abundance or relative abundance. To make spatial or temporal comparisons valid using this type of count requires the very restrictive assumption of equal detection probability for the comparisons being made. We developed a multiple-independent observer approach to estimating abundance for point count surveys as a modification of the primary-secondary observer approach. This approach uses standard capture-recapture models, including models of inherent individual heterogeneity in detection probabilities and models using individual covariates to account for observable heterogeneity in detection probabilities. We also developed a time of detection approach for estimating avian abundance when birds are detected aurally, which is a modification of the time of removal approach. This approach requires collecting detection histories of individual birds in consecutive time intervals and modeling the detection process using a capture-recapture framework. This approach incorporates both the probability a bird is available for detection and the probability of detection given availability. We also present a multiple species modeling strategy since many point count surveys collect data on multiple species and present the approach for distance sampling, multiple observer, and time of detection approaches. The purpose of using a multiple species modeling approach is to obtain more parsimonious models by exploiting similarities in the detection process among species. We present a method for defining species groups which leads to an a priori set of species groups and associated candidate models. Finally, we present a method for estimating the availability probability of birds during a point count based on singing rate or detailed singing time data. This approach requires data collected in conjunction with point count surveys that describe the singing rates or singing time distribution of the bird population of interest. The singing rate approach requires the assumption that an individual bird sings following a random process but rates may vary between birds. Analyses presented throughout this thesis demonstrate the importance of accurately modeling the detection process to estimate abundance. The importance of accounting for individual heterogeneity in detection probabilities was evident in every chapter. Using a point count method that accounts for individual heterogeneity is crucial to estimating abundance effectively and making valid spatial, temporal and species comparisons. [show more]

Type:Article

Subject:Bark beetle
<em>Dendroctonus</em> spp.
Western North American conifer forests
Lodgepole pine forests
Spruce-fir forests
Colorado

Description:Bark beetle (Dendroctonus spp.) outbreaks have historically shaped the structure and function of western North American conifer forests by contributing to heterogeneous conditions needed to support various wildlife species. Previous studies of beetle impacts have primarily focused on pine-dominated systems within 1–6 years of outbreak, limiting our knowledge for informing wildlife habitat management to a relatively short timeframe and narrow range of forest types. Increases in extent and severity of outbreaks since 1900, caused in part by anthropogenic climate warming and forest management, elevates the value of understanding how bark beetle outbreaks impact wildlife populations. Our objectives were (1) to evaluate species and community relationships with outbreak severity (percent conifer mortality) and years since outbreak, (2) to evaluate potential environmental mechanisms underlying these relationships, and (3) to compare patterns across the two forest types for improved general knowledge. We studied avian species occupancy and richness in relation to outbreak conditions using two 18-year chronosequence datasets collected in 2013 and 2014 representing lodgepole forests (predominantly Pinus contorta) and spruce-fir forests (co-dominated by Picea engelmannii and Abies lasiocarpa) throughout Colorado. We employed hierarchical models to account for imperfect detection and spatial dependencies when analyzing population and community patterns apparent in data representing 73 bird species. We found various relationships and potential underlying mechanisms largely but not entirely consistent with a priori hypotheses based on species life histories and previous study. As expected, understory-associated birds related positively with outbreak conditions apparently following understory vegetative release. Consistent with our hypotheses, aerial insectivores and snag-associated species also related positively with outbreak conditions, although our data highlighted understory vegetation more so than canopy structure or snags as potential mechanistic factors. Contrary to our overall hypothesis for canopy-associated species, we did not observe many negative outbreak relationships for this group. Overall, bird species richness increased with years since outbreak, with clear increases in lodgepole forest. In contrast, the data from spruce-fir forest provided statistical support for fewer patterns (i.e., fewer with 90% credible intervals excluding zero), and they supported primarily negative relationships with outbreak severity. Our results suggest potential differences in ecological significance of bark beetle outbreaks in different forest types. At least in lodgepole forest, however, observed patterns were apparently consistent with the purported historical value of bark beetle outbreaks for promoting biodiversity (represented here by birds) despite recent increases in extent and severity. [show more]