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Cherry Hills Village, CO, United States

Ramsdell C.P.,Virginia Polytechnic Institute and State University | Sorice M.G.,Virginia Polytechnic Institute and State University | Dwyer A.M.,Rocky Mountain Bird Observatory
Environmental Conservation | Year: 2016

Financial incentives have become a core component of private lands conservation programmes because of their ability to motivate stewardship behaviour. Concern exists about the durability of stewardship behaviours after payments end. Payments for performance may impact farmers' current and future engagement with an incentive programme to protect an at-risk ground-nesting grassland bird. Farmer motivations for participating in the programme, as well as their intention to continue the programme if the financial incentive no longer existed, were quantified. Although farmers did not report a high level of current involvement in the programme, most reported they would continue at a similar or higher level of engagement if the payments ended. These outcomes were related to their perception that their participation was driven by their internal motivation to help rather than the desire to obtain the financial reward. The perception that their behaviour was self-directed was positively influenced by the flexibility surrounding landowners' engagement with the programme, a feeling of competence and achievement, and a feeling of connectedness to the organization implementing the programme. The success of conservation incentive programmes over the long term can be enhanced by explicitly accounting for the needs of landowners in programme design and administration. © 2015 Foundation for Environmental Conservation. Source

Macias-Duarte A.,University of Sonora | Panjabi A.O.,Rocky Mountain Bird Observatory
Auk | Year: 2013

Grassland bird populations have shown persistent declines over the past four decades in North America. Possible explanations for the declines include decreased winter survival because of habitat deterioration. To address this hypothesis, we evaluated the relationship between habitat structure and winter survival of Vesper Sparrows (Pooecetes gramineus) in Chihuahuan Desert grasslands of northern Mexico. We radiotagged and monitored the survival of 102 individuals during the winters of 2009 and 2010. We obtained visual estimates of vegetation structure and composition at every individual's radiotelemetry location. We used an exponential regression model to estimate daily survival rates and determine the association between habitat structure and survival. We estimated a daily winter survival probability of 99.1% (95% confidence interval: 97.4-99.7%) for Vesper Sparrows in both years. Our survival analysis suggests that habitat structure is an important predictor of winter survival. Average grass height and shrub height were positively related to Vesper Sparrow survival. Our results suggest that grassland bird populations may be negatively affected by poor grassland conditions during the winter and that low winter survival may be an important factor in population declines. Winter habitat conditions in the Chihuahuan Desert grasslands are shaped primarily by grazing and climate, highlighting the need to improve range management, especially in Mexico, as a means to reverse persistent population declines of grassland birds. Copyright © 2013 by The American Ornithologists' Union. Source

Bartuszevige A.M.,Playa Lakes Joint Venture | Pavlacky Jr. D.C.,Rocky Mountain Bird Observatory | Burris L.,Colorado State University | Herbener K.,Colorado State University
Wetlands | Year: 2012

Playa wetlands in the western Great Plains of the United States are an essential component of the ecological and hydrological systems in the region. However, these wetlands are threatened through culturally-accelerated sedimentation from the surrounding row-crop dominated landscape. As a consequence, conservation efforts have focused mainly on installing Conservation Reserve Program (CRP) grasslands around playas but these may impede water from reaching playa basins. Thus, better understanding of the factors that influence inundation is needed for effective conservation of playas. The objectives of this project were to investigate the effects of hydrological factors, landcover at local and watershed scales, and thresholds for playa inundation in a variety of landscape conditions. We used generalized linear mixed modeling to determine the landscape and hydrological factors that influence playa inundation. We found playa inundation was positively related to amount of rainfall in the previous 14 days, the variation in amount of rainfall, playa area and the slope of the surrounding landscape. After accounting for hydrological factors, we found CRP adjacent to the playa and CRP in the watershed had a larger influence on playa inundation than the landcover of Pasture orGrassland. There was a negative non-linear effect of CRP on playa inundation and evidence for a negative linear effect at the watershed scale. Playa conservation is an integral component of the Ogallala Initiative, and Farm Bill programs such as CRP are essential conservation tools thus it is imperative that we understand potential impacts of such programs in order to inform improvements. © Society of Wetland Scientists 2012. Source

Macias-Duarte A.,University of Sonora | Panjabi A.O.,Rocky Mountain Bird Observatory
Wilson Journal of Ornithology | Year: 2013

Grassland birds are declining at an alarming rate and habitat limitation on the wintering grounds may play a major role in population declines. In an attempt to understand habitat needs and constraints of grassland bird species on their wintering grounds, we conducted the first-ever telemetry study to document the movements of a wintering grassland passerine bird in grasslands of the Chihuahuan Desert in northern Mexico. We attached radio-transmitters to 99 Vesper Sparrows in January of 2009 and 2010 and tracked them for up to 51 days. We estimated vegetation characteristics at foraging, roosting and random locations. We used kernel density estimators of the utilization distribution for each individual sparrow to estimate home range size. We found differences in average home range size between 2009 and 2010 (108.46 ± 36.43 ha and 30.91 ± 4.74 ha, respectively). Home ranges showed high levels of intraspecific overlap, with average pairwise overlap of 0.41, 0.70 and 0.79 among individuals at three study sites, as measured by the Bhattacharyya's affinity. Grasses and shrubs were shorter in foraging locations than in random sites within Vesper Sparrow core habitat, but we found no differences in grass cover and shrub cover. We suggest that movements of Vesper Sparrows are mostly limited to <1 km2 during the winter and hypothesize that these movements are subject to constraints by food limitation and predation. © 2013 by the Wilson Ornithological Society. Source

Van Der Burg M.P.,University of Nebraska - Lincoln | Bly B.,Nebraska Prairie Partners | VerCauteren T.,Rocky Mountain Bird Observatory | Tyre A.J.,University of Nebraska - Lincoln
Journal of Applied Ecology | Year: 2011

Wildlife managers are limited in the inferences they can draw about low density populations. These limits are imposed by biases in monitoring data not regularly accounted for. 2.We developed a Bayesian hierarchical model to correct biases arising from imperfect detection and spatial autocorrelation. Our analysis incorporated model selection uncertainty by treating model probabilities as parameters to be estimated in the context of model fitting. We fitted our model to count data from a monitoring programme for the mountain plover Charadrius montanus, a low density bird species in Nebraska, USA. 3.Our results demonstrated that previous accounts of the abundance and distribution of plovers in Nebraska were impacted by low detection probabilities (~5-20%). Uncorrected relative abundance estimates showed that the average number of birds per agricultural section increased over time, whereas corrected estimates showed that average abundance was stable. 4.Our method spatially interpolated relative abundance to produce distribution maps. These predictions suggested that birds were selecting some sites more frequently than others based on some habitat feature not explored in our study. Variation in mountain plover abundance appeared more heavily influenced by changes in the number of individuals occupying a few high quality sites, rather than from changes in abundance across many sites. Thus, conservation efforts may not be as efficient when focusing on low to moderate quality sites. 5.Synthesis and applications.Managers who must make decisions based on data-poor systems should adopt rigorous statistical approaches for drawing inferences. Spatial predictions provide information for deciding where to implement management, which is just as important as knowing what kind of management to apply. Our approach provides a step in the direction of making the biological signal in data-poor monitoring programmes more informative for conservation and management. © 2010 The Authors. Journal of Applied Ecology © 2010 British Ecological Society. Source

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