Browsing by Subject "Prairie Pothole Region"

Now showing 1 - 6 of 6
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    Data and model code for assessing dabbling duck age ratios and corresponding environmental correlates in the North American Prairies, 1969-2015
    (2018-05-16) Specht, Hannah M; Arnold, Todd W; spech030@umn.edu; Specht, Hannah M
    Fecundity estimates for demographic modeling are difficult to acquire at the regional spatial scales that correspond to climate shifts, land use impacts or habitat management programs, yet are important for evaluating such effects. While waterfowl managers have historically used harvest-based age ratios to assess fecundity at continental scales, widely available age ratios from late-summer banding data present an underutilized opportunity to examine a regional fecundity index with broad temporal replication. We used age ratios from banding data and hierarchical mixed-effect models to examine how fecundity of five North American dabbling duck species was affected by temporal variation in hydrological cycles, intra- and inter-specific density dependence and alternate prey availability, and whether those relationships were consistent across a broad geographic area. The data and code for these analysis are included here.
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    Effects of atrazine and climate change on amphibian larval development and growth
    (2014-04) Olker, Jennifer
    The distribution and population persistence of many North American amphibians depends on environmental factors at multiple spatial scales. Anthropogenic and naturally occurring stressors, including contaminants, predators, and pond-drying, have been shown to affect amphibian growth, development, and health. The herbicide atrazine (2-chloro-4-ethylamino-6-isoproyl-amino-s-triazine) is a widely used pesticide in the U.S., and in some amphibians has been shown to reduce size and health at metamorphosis and alter gonadal function, presumably through endocrine disruption. Environmental changes predicted by climate models could exacerbate these impacts, as well as directly affect amphibian development and population persistence through accelerated pond-drying and habitat loss or modification. Objectives of this project were to: 1) Quantify developmental responses to the combined effects of atrazine exposure and accelerated pond-drying rates; and 2) Quantify potential effects of these and other environmental stressors on amphibian occurrence and health. Growth, development, and physiological state (skeletal/eye malformations and gonadal development) were assessed in northern leopard frog (Rana pipiens) and wood frog (Rana sylvatica) in experimental exposures and field surveys in the U.S. Prairie Pothole Region across a range of environmentally relevant atrazine concentrations (0.1, 20, and 200 μg/L) and in combination with climate change and other environmental factors suspected to affect amphibian larval development. Atrazine exposure during larval development decreased survival and had sub-lethal impacts on growth and development, which could negatively impact populations by reducing annual recruitment and survival of juveniles. Presence, abundance, and severity of testicular oocytes (TOs) did not appear to be related to atrazine exposure in experimental or field specimens; however, TO prevalence differed greatly between species (>40% in R. pipiens and <5% in R. sylvatica). These results suggest that TOs are not likely due solely to endocrine disruption by atrazine and more research is needed to understand reproductive or population-level impacts of TOs. Amphibian metrics (presence, breeding, skeletal malformations, and TOs) responded differently to environmental variables from wetland, local, and landscape scales, and amphibian breeding (presence or success) was identified as a better indicator of environmental condition than species presence, calling, or TOs.
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    Habitat use and reproductive success of waterbirds in the human-dominated landscape of North America’s prairies: Using sparse data to inform management
    (2018-05) Specht, Hannah
    Information needed to implement effective management strategies requires an understanding of where, when and how target species use habitats available to them to survive and reproduce. I used new approaches for field data collection and analysis for rare and cryptic species to improve understanding of how anthropogenic and natural habitat characteristics affect the habitat use and reproductive success of grassland waterbirds, to better inform management in North America’s Northern Great Plains. Using historical data on waterfowl age ratios at banding and a database of upland shorebird nest records, I identified spatial and temporal variation in upland nesting waterfowl and shorebird fecundity. Specifically, I found positive relationships between vole population irruptions and metrics of fecundity (age ratios and nest survival) in both upland nesting waterfowl and shorebirds, and that fecundity of both groups was tightly tied to wetland conditions; increases in wetland inundation improved dabbling duck fecundity and Marbled Godwits (Limosa fedoa) experienced higher fecundity in territories with greater wetland cover. Density dependent effects were mixed across species. I used occupancy surveys with behavioral indicators of brood presence to assess whether habitat use by conservation concern upland shorebirds and Northern Pintail (Anas acuta) was altered by oil development in the Bakken oil field, using habitat suitability models to account for natural variation in habitat quality. I found reduced habitat use by breeding pairs and/or broods of all five studied species at sites with higher traffic and that Wilson’s phalarope (Phalaropus tricolor) breeding pairs avoided habitat with higher well density. Using behavior to infer brood presence facilitated identifying effects of traffic on brood habitat use where data would otherwise have been too sparse. Finally, I present a new occupancy survey sampling design that improves estimates for rare species. Management for upland-nesting waterbirds should continue to prioritize maintaining the capacity of less permanent wetland basins to rehydrate and active patch management of grassland. Infrastructure and activity that impacts grassland wildlife should be concentrated within corridors on the landscape while conservation should be concentrated in spaces between development corridors.
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    Secretive Marshbird Response to Invasive Wetland Plant Management in the Prairie Pothole Region of Minnesota
    (2021-05) Hill, Nina
    Marshbirds are difficult to survey due their secretive nature and association with dense wetland vegetation. Recently developed standardized survey protocols are used to monitor patterns of abundance, primarily at large spatial scales, but also can be used to assess marshbird response to management. We estimated abundances of 5 species of marshbirds (American bittern [Botaurus lentiginosus], least bittern [Ixobrychus exilis], pied-billed grebe [Podilymbus podiceps], sora [Porzana carolina], and Virginia rail [Rallus limicola]) in relation to vegetation management techniques of Prairie Pothole wetlands. In northwestern Minnesota, management in autumn 2105 included herbicide application to wide-spread cattail (Typha spp.) mats with the goal to break up dense vegetation patches and restore wetlands to hemi-marsh conditions. In a before-after, control-impact study design we conducted standardized call-broadcast surveys for marshbirds during breeding seasons 2015 – 2018. We observed that American bittern, pied-billed grebe, sora, and Virginia rail abundances initially decreased, and then increased at 2nd and 3rd seasons post-treatment at sites where herbicides had been applied. In west-central Minnesota, long-term vegetation management included varying frequencies of multiple control methods. Using a habitat-informed detection probability we transformed bird counts to densities to compare abundances of marshbirds across survey locations surrounded by variable amounts of suitable habitat. We compared abundances of marshbirds among categories of wetlands with management histories of low frequency of prescribed fire, high frequency of prescribed fire, and high frequency of prescribed fire and grazing. Fire and grazing as applied in the system we studied did not appear to influence Prairie Pothole Region wetland characteristics enough to result in changes in marshbird abundance, but abundance of marshbirds was related to characteristics of individual wetlands that did not appear to respond to fire and grazing. Pied-billed grebe abundance was positively associated with higher areas of open water, soras were more abundant in wetlands with high ratios of open water to emergent vegetation, and Virginia rails were more abundant in wetlands with scrub-shrub wetland cover types.
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    Secretive Marshbird Response to Invasive Wetland Plant Management in the Prairie Pothole Region of Minnesota
    (2021-03-26) Hill, Nina M; Andersen, David E; hillx725@umn.edu; Hill, Nina M; University of Minnesota, USGS Cooperative Fish and Wildlife Research Unit
    Marshbirds are difficult to survey due their secretive nature and association with dense wetland vegetation. Recently developed standardized survey protocols are used to monitor patterns of abundance, primarily at large spatial scales, but also can be used to assess marshbird response to management. We estimated abundances of 5 species of marshbirds (American bittern [Botaurus lentiginosus], least bittern [Ixobrychus exilis], pied-billed grebe [Podilymbus podiceps], sora [Porzana carolina], and Virginia rail [Rallus limicola]) in relation to vegetation management techniques of Prairie Pothole wetlands. In northwestern Minnesota, management in autumn 2105 included herbicide application to wide-spread cattail (Typha spp.) mats with the goal to break up dense vegetation patches and restore wetlands to hemi-marsh conditions. In a before-after, control-impact study design we conducted standardized call-broadcast surveys for marshbirds during breeding seasons 2015 – 2018. We observed that American bittern, pied-billed grebe, sora, and Virginia rail abundances initially decreased, and then increased at 2nd and 3rd seasons post-treatment at sites where herbicides had been applied. In west-central Minnesota, long-term vegetation management included varying frequencies of multiple control methods. We compared abundances of marshbirds among categories of wetlands with management histories of low frequency of prescribed fire, high frequency of prescribed fire, and high frequency of prescribed fire and grazing. Fire and grazing as applied in the system we studied did not appear to influence Prairie Pothole Region wetland characteristics enough to result in changes in marshbird abundance, but abundance of marshbirds was related to characteristics of individual wetlands that did not appear to respond to fire and grazing. Pied-billed grebe abundance was positively associated with higher areas of open water, soras were more abundant in wetlands with high ratios of open water to emergent vegetation, and Virginia rails were more abundant in wetlands with scrub-shrub wetland cover types.
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    Wetland bird case study for application of habitat association models across Great Lakes and Prairie Pothole regions
    (2022-12-08) Elliott, Lisa H; Bracey, Annie M; Niemi, Gerald J; Johnson, Douglas H; Gehring, Thomas M; Gnass Giese, Erin E; Fiorino, Giuseppe E; Howe, Robert W; Lawrence, Gregory J; Norment, Christopher J; Tozer, Douglas C; Igl, Lawrence D; harnx012@umn.edu; Elliott, Lisa H; Coastal Wetland Monitoring Program; Great Lakes Marsh Monitoring Program; Dakotas Wetland Survey
    Species often exhibit regionally specific habitat associations, and, thus, habitat association models developed in one region might not be accurate or even appropriate for other regions. Three programs to survey wetland-breeding birds covering (respectively) North American wetland breeding bird survey programs in Great Lakes coastal wetlands, inland Great Lakes wetlands, and the Prairie Pothole Region offer an opportunity to test whether regionally specific models of habitat use by wetland-obligate breeding birds are transferrable across regions. This dataset includes wetland bird point count and habitat characteristics data from the Great Lakes Coastal Wetland Monitoring Program (2016-2017) and Great Lakes Marsh Monitoring Program (1995-1997 and 2016-2017). These data are then combined with publicly available data from the Dakotas Wetland Survey (1995-1997). The included code files cover the creation and selection of habitat association models, and test the transferability of these models across datasets. These data are now released to accompany publication of "Application of habitat association models across regions: useful explanatory power retained in wetland bird case study."