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River Road, ND, United States

Skone B.R.,Montana State University | Rotella J.J.,Montana State University | Walker J.,Great Plains Regional Office
Journal of Wildlife Management | Year: 2016

The Prairie Pothole Region (PPR) of North America produces more than 50% of North America's upland-nesting ducks. With the recent increase in economic value of some cash-crops and the potential to lose productive nesting habitat enrolled in the Conservation Reserve Program (CRP), there has been interest in evaluating the efficacy of alternative farming practices to provide additional breeding habitat for waterfowl. We evaluated and compared daily survival rates (DSR) of duck nests (Anas spp.) in winter wheat with those in perennial cover. We also examined the number of hatched nests/ha in each habitat and compared them to estimates in spring wheat to put habitat-specific estimates of nest survival in perspective. We monitored 1,195 nests in winter wheat and 3,147 in perennial cover in North and South Dakota on 13-19, 10.36-km2 sites each year from 2010 to 2012. In 2010, we also monitored 75 nests in spring wheat. We used an information-theoretic approach to develop and evaluate a set of competing models based on plausible and previously established covariates affecting nest survival. Across all species, nest survival was at least as high in winter wheat as in perennial cover, and for northern pintails and mallards, estimated nest survival rates were greater in winter wheat. Nest survival also varied by year and study area, was positively related to nest age, and was negatively related to the number of wetland basins, the proportion of cropland in the landscape, and vegetation density. Density of hatched nests in perennial cover (0.14/ha) was on average twice as high as nests in winter wheat fields (0.07/ha), which was in turn 4 times higher than estimates for spring wheat fields (0.02/ha). Our results provide evidence that winter wheat could be a useful tool for wildlife managers seeking to add productive nesting habitat in landscapes under intensive crop production. © 2015 The Wildlife Society. Source

Walker J.,Great Plains Regional Office | Rotella J.J.,Montana State University | Stephens S.E.,Great Plains Regional Office | Lindberg M.S.,University of Alaska Fairbanks | And 3 more authors.
Ecological Applications | Year: 2013

The Prairie Pothole Region (PPR) is the primary breeding region for most species of North American dabbling ducks (Anas spp.). Conservation of these species is guided in part by knowledge of relationships between nest survival probability and habitat features. Positive relationships between duck nest survival and amount and configuration of herbaceous perennial vegetation have been observed in previous studies, but these 2- to 4-year studies might not have adequately characterized the temporal effect of wet-dry episodes on nest survival. Over an eight-year period, we studied nest survival of five species of ducks in the PPR relative to spatial and temporal variation in pond density, primary productivity, and hydrologic status of wetlands, soil, and vegetation on 52 study sites selected to span a gradient of spatial variation in proportion of herbaceous perennial vegetation and in number of wetland basins. We observed the fate of 12 754 nests. Consistent with past studies, 90% of nests that failed to hatch were destroyed by predators. Nest survival probability was positively related to current-year pond density and primary productivity, negatively related to pond density and primary productivity during the previous two years, and positively related to the number of wetland basins on the study site. Predicted relationships between nest survival and proportion or configuration of herbaceous perennial vegetation in the surrounding landscape were not supported. For mallard (Anas platyrhynchos), median estimated nest survival probability ranged from 0.02 (SE = 0.01) to 0.22 (SE = 0.02). Estimated nest survival was greatest on sites with numerous wetland basins that had transitioned from dry, unproductive conditions to wet, productive conditions in the previous 1-2 years. Our results were consistent with time-lagged responses of food webs to resource pulses in a broad array of ecosystems. Our study highlighted the importance of wetland basins and wet-dry episodes to duck nest survival in the PPR. Current habitat conservation efforts focus on landscapes with numerous wetland basins and a high proportion of herbaceous perennial vegetation. Our results suggest that future conservation efforts should focus on preserving high-density wetland complexes across as large a geographic extent as possible even in cropland-dominated landscapes. © 2013 by the Ecological Society of America. Source

Gue C.T.,University of North Dakota | Walker J.A.,Great Plains Regional Office | Mehl K.R.,University of North Dakota | Mehl K.R.,U.S. Fish and Wildlife Service | And 8 more authors.
Journal of Wildlife Management | Year: 2013

The wetlands and grasslands of the Prairie Pothole Region (PPR) make it the most productive breeding habitat for North American ducks. The growth rate of mallard (Anas platyrhynchos) populations is sensitive to changes in survival of adult females during the breeding season. Much of the PPR is suitable for large-scale wind-energy development and collisions of breeding females with wind turbines may be a novel source of mortality in this area. We assessed the effects of wind energy on breeding female mallard and blue-winged teal (A. discors) survival by monitoring 77 radio-marked mallards and 88 blue-winged teal during the 2009 and 2010 breeding seasons at the Tatanka Wind Farm (TWF) near Kulm, North Dakota. During the same period, we monitored 70 female mallards and 75 blue-winged teal at an adjacent reference site without wind turbines (REF). We used an information-theoretic approach to investigate relationships between female survival and site (TWF vs. REF), year (2009 vs. 2010), and date. Collision mortalities were rare. Only 1 radio-marked female mallard and no blue-winged teal collided with wind turbines. Most mortalities were caused by predators (78.3%; 36/46), irrespective of species and site. For mallards, the best-approximating model indicated that breeding season survival was 1) lowest when a high proportion of radio-marked females were incubating, and 2) dependent on year and site such that expected survival (Ŝ) in 2009 was higher at TWF (Ŝ = 0.90, 85% CI = 0.79-0.98) than at REF (Ŝ = 0.83, 85% CI = 0.68-0.95), but expected survival in 2010 was lower at TWF (Ŝ = 0.62, 85% CI = 0.46-0.79) than at REF (Ŝ = 0.84, 85% CI = 0.72-0.94). For blue-winged teal, the constant model was the best-approximating model and indicated that expected female survival was 0.75 (85% CI = 0.69-0.82). The most competitive model for blue-winged teal that included the effect of wind turbines indicated that expected survival at TWF (Ŝ = 0.71, 85% CI = 0.62-0.79) was lower than survival at REF (Ŝ = 0.81, 85% CI = 0.73-0.89). The limited number of collisions observed for female mallards and blue-winged teal nesting at TWF suggests that wind turbines had no direct effect on female survival. Thus, conservation strategies that include protection of wetland and grassland habitat in wind-developed landscapes will most likely not cause a direct reduction in survival of breeding females due to collisions with wind turbines. © 2013 The Wildlife Society. Copyright © The Wildlife Society, 2013. Source

Loesch C.R.,U.S. Fish and Wildlife Service | Walker J.A.,Great Plains Regional Office | Reynolds R.E.,U.S. Fish and Wildlife Service | Gleason J.S.,U.S. Fish and Wildlife Service | And 4 more authors.
Journal of Wildlife Management | Year: 2013

Industrial wind energy production is a relatively new phenomenon in the Prairie Pothole Region and given the predicted future development, it has the potential to affect large land areas. The effects of wind energy development on breeding duck pair use of wetlands in proximity to wind turbines were unknown. During springs 2008-2010, we conducted surveys of breeding duck pairs for 5 species of dabbling ducks in 2 wind energy production sites (wind) and 2 paired reference sites (reference) without wind energy development located in the Missouri Coteau of North Dakota and South Dakota, USA. We conducted 10,338 wetland visits and observed 15,760 breeding duck pairs. Estimated densities of duck pairs on wetlands in wind sites were lower for 26 of 30 site, species, and year combinations and of these 16 had 95% credible intervals that did not overlap zero and resulted in a 4-56% reduction in breeding pairs. The negative median displacement observed in this study (21%) may influence the prioritization of grassland and wetland resources for conservation when existing decision support tools based on breeding-pair density are used. However, for the 2 wind study sites, priority was not reduced. We were unable to directly assess the potential for cumulative impacts and recommend long-term, large-scale waterfowl studies to reduce the uncertainty related to effects of broad-scale wind energy development on both abundance and demographic rates of breeding duck populations. In addition, continued dialogue between waterfowl conservation groups and wind energy developers is necessary to develop conservation strategies to mitigate potential negative effects of wind energy development on duck populations. Published 2012. This article is a U.S. Government work and is in the public domain in the USA. © Published 2012. This article is a U.S. Government work and is in the public domain in the USA. Source

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