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Resumen.—Evaluamos las asociaciones entre el Programa de Conservación de Reservas (PCR) y las poblaciones de Phasianus colchicus mediante modelos utilizando los conteos de P. colchicus realizados por el Muestreo de Aves Reproductivas (BBS, por sus siglas en inglés) entre 1987 y 2005 a lo largo de 388 rutas en nueve estados. Los conteos de P. colchi...
Contexts in source publication
Context 1
... assigned each BBS route to a LRR (Figure 2). The LRR information was downloaded as an ArcInfo coverage from The BBS routes from each state were overlain onto the map of the LRRs. To assign routes to LRRs, the shapefile containing the BBS routes was “intersected” with the shapefile containing the LRRs. For routes crossing LRR boundaries, each route was assigned to the LRR that contained the most ...
Context 2
... goal was to provide a thorough, objective, and scientifically rigorous methodology to: 1) relate indices of ring-necked pheasant populations based on the Breeding Bird Survey (BBS, administered by the United States Geological Survey (USGS); - pwrc.usgs.gov/bbs/bbs.html) to land use changes and habitat development due to CRP practices, and 2) allow FSA to annually generate updated estimates of the responses. Analyses were performed on Land Resource Regions (LRR) (Figure 2) and aggregated into summary statistics for all states for which data were available. The methodology and models should allow the FSA to expand the methods into states and regions as additional CRP lands and practices are digitized into a GIS, and potentially to other breeding bird species. The methodology, analyses and model selection can be performed and repeated periodically to track effects of changes in CRP lands on changes in ring-necked pheasant population trends, resulting from new enrollments and expiration of existing ...
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Citations
... Long-term cropland retirement programs have long been recognized as successful conservation strategies for soil, water, and wildlife resources in the United States (e.g., Dahlgren, 1967;Duebbert, 1969;Harmon and Nelson, 1973), but none has received as much attention from conservation and wildlife groups in the United States as the CRP. Perennial grasslands enrolled in CRP have benefited many grassland bird species by establishing millions of hectares of nesting habitat Schwartz, 1993a, 1993b;Reynolds et al., 1994Reynolds et al., , 2001Best et al., 1997;Herkert, 1998;Koford, 1999;Nielson et al., 2008). The ecological benefits of providing the nesting habitat have resulted in higher nesting success than alternative vegetation types (Kantrud, 1993;Johnson, 2000;Jones-Farrand et al., 2007;Koford, 1999;Reynolds et al., 2001), more connectivity in an increasingly fragmented landscape (Johnson, 2000;Johnson and Igl, 2001;Drum et al., 2015), and positive population growth rates (Reynolds et al., 1994;Herkert, 1997Herkert, , 1998Herkert, , 2007Herkert, , 2009Ryan et al., 1998;Riffell et al., 2008). ...
Recent declines of grassland bird populations in North America are linked to habitat loss and fragmentation associated with agricultural practices. One tool used to conserve soil, water and
wildlife habitat on agricultural fields is the U.S. Department of Agriculture’s Conservation Reserve Program (CRP), the largest agricultural conservation program in the United States. Managers and conservationists recognize CRP as an important component of conserving grassland birds in the central portion of the United States. However, recent widespread expiration of CRP contracts could negatively influence grassland bird populations. Few studies have evaluated how former CRP-enrolled fields may function as grassland bird habitat. In this paper, we analyzed data from a long-term (1990–2017) study aimed at comparing grassland bird abundance (24 species) between idled CRP grasslands and fields where the CRP contracts expired. Some of these fields where contracts expired were maintained as pasture or hayland, and others were converted back to cropland. Estimated abundances of most species were considerably higher in idled CRP than in fields with expired CRP contracts. Post-CRP land use also appeared to affect most bird abundances, with lower abundance in grazed grasslands and haylands relative to idled CRP, but higher abundance than cropland. The responses of obligate and facultative grassland specialists to post-CRP management varied among species, with some being negative and some being positive depending on post-CRP land use, which is unsurprising given the variable habitat requirements of grassland birds. Our results have implications for wildlife managers who must design conservation strategies around the land use decisions of private landowners. Our results support the idea of maintaining a mosaic of undisturbed CRP grasslands and post-CRP grasslands that are hayed or grazed, which should guarantee some undisturbed nesting cover in the landscape for some bird species and some disturbed grasslands that may have long-term benefits for other species.
... Areas of Illinois with high first-order stream density also often include large amounts of heterogeneous edge habitat, such as the areas around the tributaries of the Illinois, Mississippi, and Ohio Rivers in western and southern Illinois. Pheasant occupancy was most associated with forest cohesion, indicating pheasant avoidance of forested areas (Schmitz andClark 1999, Kauth 2020) and selection of agricultural areas (which are highly negatively correlated with forest cover in Illinois; Nielson et al. 2008). Surprisingly, the vast majority of the models with the lowest AIC value for pheasant included only forest cohesion, and not other covariates known to be associated with pheasant occupancy, such as proportion of grassland. ...
Bird populations have declined across North America over the past several decades. Bird monitoring programs are essential for monitoring populations, but often must strike a balance between efficiency of data collection and spatial biases. Species- or habitat-specialist-specific monitoring programs may be helpful for increasing efficiency of sampling and understanding effects of management actions, but may be subject to preferential sampling bias if they are used to assess large-scale occupancy or abundance and monitoring is largely focused in high-quality habitat. More general monitoring programs, such as the North American Breeding Bird Survey (BBS) and eBird, may not preferentially sample specialists’ habitats but are subject to other forms of bias and often do not efficiently sample specialists’ habitats. We used an integrated occupancy model combining data from eBird, BBS, and Illinois state surveys of upland game bird habitat areas to estimate drivers of Northern Bobwhite (Colinus virginianus) and Ring-Necked Pheasant (Phasianus colchicus) occupancy and compare inference from single-visit, multi-visit, and integrated monitoring programs. We fit sets of candidate models using every combination of the 3 datasets except for eBird by itself, to better understand how differences in spatial biases between programs affect ecological inference. We found that, for both bobwhite and pheasant, state surveys of upland habitat increased the predictive ability of models, and BBS data usually improved inference on occupancy parameters when it was integrated with other data sources. Integrating multiple data sources partially resolved the spatial gaps in each monitoring program, while also increasing precision of parameter estimates. Integrated models may be capable of combining the higher sampling efficiency of targeted monitoring programs with the more even spatial coverage of broad-scale monitoring programs.
... Recognizing the most valuable farmland areas makes it easier to target habitat management measures and to emphasize these landscape features while upholding a high food production capacity of the farming enterprise. Nielson et al. (2008) considered the pheasant a good indicator of agricultural landscapes and of the successional habitat created by a conservation reserve program (CRP) in the USA. ...
Agricultural intensification has significantly impacted habitat structures in agricultural landscapes and is one of the main drivers of biodiversity decline, especially in farmland birds. Birds are considered to reflect well the trends in other biodiversity elements and are therefore often used as indicator species. We studied common pheasant (Phasianus colchicus) brood habitat use in a small-grain-dominated farmland in southern Finland. The broods significantly preferred field margins compared to their availability. The importance of field margins was underlined, as 68% of pheasant brood observations in grain fields were within a 25-m-wide zone from the field edge, despite the availability being only 40% of the field area. Our results support the idea that field margins and their proximity act as possible biodiversity reservoirs even in intensive farming systems. Increasing the amount of field margins can be an effective management method when aiming to improve success of common pheasant broods while simultaneously benefitting farmland biodiversity. Identifying key habitats and landscape features that allow the co-existence of biodiversity and effective food production is crucial when aiming to halt the ongoing biodiversity collapse.
... Although CRP has clearly been a successful conservation tool for prairie-obligate species including lesser prairie chickens (Dahlgren et al. 2016;Sullins et al. 2019), grasshopper sparrows (Ammodramus savannarum; Herkert 1998), and coyotes (Kamler et al. 2005), these efforts may be indirectly constraining distributions of swift foxes on the edge of their range. Seeding mixtures associated with CRP focus on creating vegetation communities not associated with short grass prairie communities (Sovada et al. 2003;Plumb et al. 2019), resulting in taller vegetation [e.g., big bluestem (Andropogon gerardii), switchgrass (Panicum virgatum)] suitable for other species such as non-native ring-necked pheasant populations (Phasianus colchicus; Nielson et al. 2008). CRP seeding mixtures that shift vegetation composition to taller species (> 30 cm) may inhibit the visual range of swift foxes and increase predation risk in these areas (Kamler et al. 2003;Thompson and Gese 2007). ...
Context
Human-modified landscapes can structure species’ distributions and supplant traditional biotic range-limiting processes. Understanding the direction and scale of these processes is necessary to enhance species conservation efforts.
Objectives
We investigated how the distribution of a prairie-obligate carnivore, swift fox (Vulpes velox), is influenced by landscape pattern at the eastern edge of their used range. We also assessed the effects of a popular conservation effort, the conservation reserve program (CRP), on swift fox distributions.
Methods
We used three years of detection/non-detection data (2018–2020) from camera traps at 381 sites to evaluate the spatial distribution of swift foxes at the eastern edge of their extant range in Kansas, USA. We used Gaussian Kernel functions to identify optimal scales of effect for measured landscape covariates and multiseason use models to reveal potential range-limiting constraints.
Results
Swift foxes were more likely to occur at sites with moderate landcover diversity within 254.47 ha, greater proportion of shortgrass prairie (7.07 ha) and loamy soil types (0.79 ha), and lower proportions of CRP landcover (78.54 ha). Swift foxes were more likely to colonize sites with less diverse landcover, a greater proportion of loamy soil types, and lower proportions of CRP landcover. Swift foxes were insensitive to the proportion of row-crop agriculture surrounding sites (3.14 ha).
Conclusions
Loamy soils and distribution of shortgrass prairie ecosystems may shape the periphery of the distribution for swift foxes. Landscape-scale use of CRP may constrain swift fox distributions at their range edge because managed vegetation structure of CRP does not mimic native shortgrass prairie.
... These declines have been attributed to many factors including fragmentation of remaining grassland habitat and more intensive agricultural practices such as greater agrochemical applications, and larger, monocrop fields (Hill et al., 2014;Mineau and Whiteside, 2013;Murphy and Moore, 2003). Previous studies have demonstrated important linkages between grassland bird populations and habitat features at various scales (Cunningham and Johnson, 2006;Helzer and Jelinski, 1999;Hovick et al., 2014;Nielson et al., 2008), and the importance of grasslands to grassland birds is well supported, yet grasslands continue to be converted for human use at alarming rates (Lark et al., 2015;Wimberly et al., 2017). For example, Lark et al. (2015) estimated 7.3 M acres of uncultivated land were converted to cropland in the U.S. between 2001 and 2012. ...
Although declines in grassland birds have been documented, national initiatives to conserve grasslands and their biota have fallen short in part because the non-market values of natural ecosystems and species are often not recognized in political decision making. Identifying shared, anthropogenic threats faced by market-valued and non-market-valued species may generate additional support for grassland conservation. We quantify the relationship between the market value of grasslands to commercial beekeepers and the importance of grasslands for birds of conservation concern in North and South Dakota. Our models estimated beekeeping annual revenue increased by $7525 USD and grassland bird abundances increased 2 to 7% per 10-km² increase in grassland area. We estimated grassland conversion from 2006 to 2012 resulted in a $2.0 to $2.8 M USD decrease in annual revenue for beekeepers in the Dakotas. Through this study we demonstrate both the market value of grasslands to commercial beekeepers and the non-market benefits of grasslands in supporting migratory birds and discuss the implications of future land-use change. As grassland conversion and subsequent biodiversity loss continue, understanding the co-benefits of grassland conservation may be necessary to illuminate their contributions to society.
... Although CRP has clearly been a successful conservation tool for prairie-obligate species including lesser prairie chickens Sullins et al. 2019), grasshopper sparrows (Ammodramus savannarum; Herkert 1998), and coyotes , these efforts may be indirectly constraining distributions of swift foxes on the edge of their range. Seeding mixtures associated with CRP focus on creating vegetation communities not associated with short grass prairie communities Nielson et al. 2008). CRP seeding mixtures that shift vegetation composition to taller species (>30 cm) may inhibit the visual range of swift foxes and increase predation risk in these areas . ...
The Great Plains region has undergone extensive conversion of native prairies to agriculture production and energy development since European colonization. Temperate prairies, including remaining prairies within the Great Plains, are considered among Earth’s most imperiled ecosystems. Prairie patches now exist as components of a landscape mosaic proportionately dominated by cultivated agriculture. These contemporary human-modified landscapes may structure species’ distributions, influence community dynamics, and supplant established abiotic range-limiting processes. Understanding the direction and scale of these processes, and how they are affected by landscape composition and configuration, is necessary to enhance conservation efforts. Carnivore communities may be most affected by landscape changes due to negative interactions with humans and their inherent biological traits; however, information regarding landscape-scale effects on the existing suite of carnivores in the Great Plains is lacking. I examined how landscape composition and characteristics influenced site occupancy probabilities and turnover rates by swift foxes (Vulpes velox), the spatial and temporal interactions between swift foxes and coyotes (Canis latrans), and carnivore richness in agro-prairie ecosystems. Additionally, I strategically identified native prairie areas to focus conservation and management of remaining swift fox habitat.
During 2018-2020, I used detection/non-detection data from camera traps at 381 randomly selected sites distributed throughout a landscape mosaic comprising the westernmost 31 counties (7.16 million ha) of Kansas, USA. I subsequently used presence/absence data from these sites across three years to infer species-specific responses to landscape change and carnivore community dynamics. To evaluate effects of landscape composition and configuration on site occupancy probabilities and turnover rates by swift fox, I used a distance-weighted scale of effect of landscape metrics within multi-season occupancy models. Swift foxes were more likely to occur at sites with moderate landcover diversity within 254.47 ha, greater proportion of shortgrass prairie (7.07 ha) and loamy soil types (0.79 ha), and lower proportions of Conservation Reserve Program (CRP) landcover (78.54 ha). Swift foxes were more likely to colonize sites with less diverse landcover, a greater proportion of loamy soil types, and lower proportions of CRP landcover. Swift foxes were insensitive to the proportion of row-crop agriculture surrounding sites (3.14 ha). To evaluate landscape composition effects on swift foxes and coyote (the apex predator in the region) spatiotemporal interactions, I used a Bayesian hierarchical multi-season occupancy model to evaluate spatial interactions, and a coefficient of overlap of temporal activity to assess factors affecting temporal interactions. Mean persistence of swift foxes differed across sites where coyotes were not detected (0.66; SE = 0.001) and where coyotes were detected (0.39; SE=0.001). The coefficient of overlap at sites surrounded by lower proportions of CRP (≥0.10) differed (95% CIs did not overlap) from coefficient of overlap of all other landscape effects. The spatial distribution of swift foxes was positively influenced (Species Interaction Factor [SIF] > 1) by coyote presence through space and time at low proportions of CRP (≤0.04). SIF decreased as proportion of CRP increased; however, Bayesian confidence intervals overlapped SIF = 1, suggesting that swift foxes were spatially distributed independent of coyotes through space and time at greater proportions of CRP (>0.04).
I used a structural equation model to test hypotheses of multiple direct and indirect relationships between landscape composition and configuration and prey availability on carnivore richness. My hypothesized model (X2 = 23.92, df = 24, P = 0.47) explained 27% of the variance of carnivore richness. Agriculture, native prairie, landcover diversity, CRP, water availability, prey occurrence, and sampling effort all had direct positive effects on my measure of carnivore richness, while loamy tableland soil had only an indirect effect. To strategically identify native prairie areas for conservation of swift fox habitat, I created a predicted swift fox occupancy map based on my most-supported, stacked single-season occupancy model. I identified predicted occupancy rate (range = 0.01–0.46) where sensitivity equaled specificity (0.09) within a receiver operating characteristic curve, and reclassified the predicted occupancy map to include only predicted occupancy rates >0.09, and again for a more targeted approach with predicted occupancy rates >0.18. These two maps were intersected with a map of grassland proportions >0.60 to identify areas that were expected to have relatively high occupancy and survival rates by swift fox. Swift foxes were more likely to occur at sites with low levels of landscape diversity (β = -0.411 ± 0.140), greater proportions of native grassland (β = 0.375 ± 0.154) and loamy tableland soils (β = 0.944 ± 0.188), and lower proportions of CRP landcover (β = -1.081 ± 0.360). Identified native grassland conservation areas totaled 84,420.24 ha (mean patch size = 162.66 ha [SE = 29.67]). Conservation areas located on privately owned working lands included 82,703.86 ha, while conservation areas located within the boundaries of federal, state, and non-governmental organizations (NGO) parcels included 1,716.38 ha.
My results provide a unique understanding of how landscape composition and configuration, intraguild competition, and prey availability drive carnivore community dynamics in agro-prairie ecosystems. Additionally, my research elucidated constraints to range expansions for an iconic prairie-obligate carnivore (swift fox) at the edge of their range, while also identifying areas for strategic conservation for their populations.
... Therefore, it is prudent to research alternative management approaches and their application toward pheasant populations in California. It follows that pheasants are charismatic, nonmigratory and sensitive to changes in the environment (Coates et al. 2017b), and relative annual abundance can be tracked using standardised survey methodology (Rice 2003), which lend well to pheasants acting as a potential indicator of the overall health of agricultural landscapes in supporting avian populations (Nielson et al. 2008). Hence, populations of pheasants, particularly in the Central Valley of California, may shed light on the overall function of farmland habitats for other avian species that are often logistically challenging to monitor. ...
... An understanding of such mechanisms in choice and the consequence for nesting pheasants helps inform factors that are likely to be important to land managers interested in sustaining pheasant populations in human-modified environments. Similar analytical methods could be extended to other farmland birds (Nielson et al. 2008), which could also help direct future management strategies in similarly changing agricultural landscapes. Such indicator species are important because agricultural intensification continues to be a leading driver in substantial declines of farmland biodiversity (Chamberlain et al. 2000;Benton et al. 2003) and, without guided management, may imperil the productivity of these systems. ...
Context: The ring-necked pheasant (Phasianus colchicus) has experienced considerable population declines in recent decades, especially in agricultural environments of the Central Valley of California. Although large-scale changes in land cover have been reported as an important driver of population dynamics, the effects of microhabitat conditions on specific demographic rates (e.g. nesting) are largely unknown.
Aims: Our goal was to identify the key microhabitat factors that contribute to wild pheasant fitness by linking individual-level selection of each microhabitat characteristic to the survival of their nests within the California Central Valley.
Methods: We radio- or GPS-marked 190 female ring-necked pheasants within five study areas and measured nest-site characteristics and nest fates during 2013–2017. Specifically, we modeled microhabitat selection using vegetation covariates measured at nest sites and random sites and then modeled nest survival as a function of selecting each microhabitat characteristic.
Key results: Female pheasants tended to select nest sites with greater proportions of herbaceous cover and avoided areas with greater proportions of bare-ground. Specifically, perennial grass cover was the most explanatory factor with regard to nest survival, but selection for increasing visual obstruction alone was not shown to have a significant effect on survival. Further, we found strong evidence that pheasants selecting sites with greater perennial grass height were more likely to have successful nests.
Conclusions: Although pheasants will select many types of vegetation available as cover, our models provided evidence that perennial grasses are more beneficial than other cover types to pheasants selecting nesting sites.
Implications: Focusing management actions on promoting perennial grass cover and increased heights at the microsite level, in lieu of other vegetative modifications, may provide improved quality of habitat for nesting pheasants and, perhaps, result in increased productivity. This is especially important if cover is limited during specific times of the nesting period. Understanding how microhabitat selection influences fitness can help land managers develop strategies to increase the sustainability of hunted populations of this popular game-bird species.
... For example, the Northern Great Plains contains much of the Prairie Pothole Region, an area where CRP contributes greatly to waterfowl habitat. Nielson et al. (2008) estimate that a mere four percent increase in CRP acreage leads to a 22 percent rise in pheasant counts, suggesting that even small changes in CRP due to crop insurance can have large impacts on wildlife. Financial consequences may also follow given the economic importance of recreational bird hunting in the Prairie Pothole Region. ...
I directly estimate the acre-for-acre impact of crop insurance participation on Conservation Reserve Program (CRP) enrollment at the county level. The government may be sponsoring competing interests if subsidized insurance expands production at the expense of CRP. I employ an instrumental variables technique to correct for endogeneity in insurance decisions. Results suggest that an additional 1,000 acres insured reduces CRP enrollment by about three acres, though effect sizes vary by region. Local policy initiatives such as conservation compliance incentives could help offset local environmental consequences of converting land from CRP to insured production.
... During June-August 2016, we visited and verified mapped areas of CRP enrollment reconstruction within survey blocks to ensure that land-cover data were correct. Because the shapefiles obtained from the Farm Service Agency included all CRP practice codes within survey blocks, we distinguished the CRP practice codes that provide grassland cover types used by greater prairiechickens (Table S1, available online in Supporting Information) using classification categories of Nielson et al. (2008) and Drum et al. (2015). ...
Both the abundance of greater prairie‐chickens (Tympanuchus cupido pinnatus) and the area of grassland enrolled in the Conservation Reserve Program (CRP) in northwestern Minnesota, USA, have recently declined. Although wildlife conservation is a stated objective of the CRP, the impact of the CRP on greater prairie‐chicken populations has not been quantified. To address that information need, we evaluated the association between greater‐prairie chicken lek density (leks/km2), the number of males at leks (males/lek), and CRP enrollments in the context of landscape structure and composition in northwestern Minnesota. Using data from standardized prairie‐chicken surveys and land cover in 17 41‐km2 survey blocks during 2004–2016, we used a mixed‐effect model and a layered approach in an information‐theoretic framework at multiple spatial scales to identify covariates related to prairie‐chicken abundance. At the landscape scale, lek density was best explained by the amount of CRP grassland and wetland, grassland and wetland with long‐term conservation goals (state, federal, and The Nature Conservancy owned); other wetlands managed with variable or no continuity in conservation goals; the contiguity of grasslands; and the number of patches of grasslands and wetlands in each survey block each year. Increasing the amount of CRP grassland in 41‐km2 survey blocks by 1 km2 (2.4%) resulted in a corresponding increase of 6% in lek density. At the lek scale, the number of males per lek was best explained by the amount of CRP grassland and other grassland, CRP wetland and other wetland, forests, developed areas, shrubland, and the contiguity of CRP grassland. Increasing the amount of CRP grassland in the 2‐km breeding‐cycle habitat radius around a lek by 25% (3 km2) corresponded to a 5% increase in males per lek. Our results suggest that both increasing the quantity of grassland CRP and wetland CRP enrollments and aggregating CRP grassland enrollments may increase greater prairie‐chicken abundance. Our models indicated that lek density and a number of males per lek of greater prairie–chickens were related to the amount and configuration of Conservation Reserve Program (CRP) enrollments in the agricultural landscape of northwestern Minnesota, USA. Our results suggest that increasing the quantity of grassland CRP and wetland CRP enrollments and aggregating CRP grassland enrollments may increase greater prairie‐chicken abundance.
... During June-August 2016, we visited and verified mapped areas of CRP enrollment reconstruction within survey blocks to ensure that land-cover data were correct. Because the shapefiles obtained from the Farm Service Agency included all CRP practice codes within survey blocks, we distinguished the CRP practice codes that provide grassland cover types used by greater prairiechickens (Table S1, available online in Supporting Information) using classification categories of Nielson et al. (2008) and Drum et al. (2015). ...
