Geology topics

James A. Dubovsky

Publications and source records attributed to James A. Dubovsky.

7 recordsLinked to original sources

USGS2020

Linking landscape-scale conservation to regional and continental outcomes for a migratory species

Land-use intensification on arable land is expanding and posing a threat to biodiversity and ecosystem services worldwide. We develop methods to link funding for avian breeding habitat conservation and management at landscape scales to equilibrium abundance of a migratory species at the continental scale. We apply this novel approach to a harvested bird valued by birders and hunters in North America, the northern pintail duck ( Anas acuta ), a species well below its population goal. Based on empirical observations from 2007–2016, habitat conservation investments for waterfowl cost $313 M and affected less than 2% of the pintail’s primary breeding area in the Prairie Pothole Region of Canada. Realistic scenarios for harvest and habitat conservation costing an estimated $588 M (2016 USD) led to predicted pintail population sizes less than 3 M when assuming average parameter values. Accounting for parameter uncertainty, converting 70–100% of these croplands to idle grassland (cost: $35.7B–50B) is required to achieve the continental population goal of 4 M individuals under the current harvest policy. Using our work as a starting point, we propose continued development of modeling approaches that link conservation funding, habitat delivery, and population response to better integrate conservation efforts and harvest management of economically important migratory species.

Scientific Reports↗

USGS2020

Sources and dynamics of international funding for waterfowl conservation in the Prairie Pothole Region of North America

Context: Funding for habitat-management programs to maintain population viability is critical for conservation of migratory species; however, such financial resources are limited and can vary greatly over time. The Prairie Pothole Region (PPR) of North America is an excellent system for examining spatiotemporal patterns of funding for waterfowl conservation, because this transboundary region is crucial for reproduction and migration of many duck species. Aims: We examine large-scale spatiotemporal variation in funding for waterfowl habitat conservation in the PPR during 2007–2016. Specifically, we quantify major sources of funding and how funds were directed towards particular geographies within Canada and the USA. We further examine how sources and magnitude of funding changed over time and in relation to numbers of hunters. Methods: We assembled data from multiple sources to quantify funding (in US$, 2016 values) from (1) USA states and non-government organisations (NGOs), (2) Canadian government and NGOs, and (3) major USA-based federal funding sources to the Canadian and US portions of the PPR between 2007 and 2016. We fit linear regressions to examine spatiotemporal variation in funding and in numbers of active waterfowl hunters in the USA. Key results: Whereas annual funding for the Canadian portion was comparatively stable throughout the 10 years (range: US$25–41 million), funding for the US portion was dynamic and increased between the first (range: US$36–48 million) and second (range: US$43–117 million) 5-year intervals, despite concurrent declines in the number of active waterfowl hunters in the USA. Conclusions: We discovered contrasting trends and dynamics in multiple streams of funding for habitat conservation on each side of the border bisecting the PPR. These findings and approaches warrant closer attention by wildlife professionals. Work is needed to analyse past and future funding for habitat conservation, which can then be used to refine plans for maintaining or recovering populations of migratory species. Implications: Although funding for waterfowl habitat conservation in the PPR increased over the past decade, trends were inconsistent among subregions and uncertain for some major funding sources. Better understanding of the complexities in funding will help inform more efficient long-term planning efforts for conservation of waterfowl and other migratory species.

Wildlife Research↗

USGS2019

Multi-country willingness to pay for transborder migratory species conservation: A case study of Northern Pintails

Using contingent valuation, we estimated willingness to pay (WTP) in Canada, Mexico, and the United States to protect habitat for Northern Pintails (hereafter pintails), a migratory waterfowl species that provides benefits to and requires habitat in the three countries. Our study contributes to research on spatial subsidies by measuring the value of migratory species habitat. While WTP to protect pintail habitat is highest in the household's own country, there also is substantial WTP to protect pintail habitat in the other two countries. Canadian households' annual WTP is US$12 (all dollar values are in 2016 US dollars) to stabilize the pintail population in Canada, US$4 in Mexico, and US$5 in the U.S. Mexican households would pay US$8 in Mexico, US$5 in the U.S., and US$5 in Canada. U.S. households would pay US$28 in the U.S., US$18 in Canada, and US$16 in Mexico. WTP is statistically significantly higher in all three countries to increase the pintail population. WTP as a percentage of household income is statistically significantly higher for respondents in Mexico. WTP is logically related to explanatory variables such as respondent income, interest in hunting waterfowl, and financial support of wildlife conservation organizations. This study has important implications for conducting economic analyses of habitat issues of transboundary migratory species' conservation and to more effectively and equitably achieve conservation goals.

Ecological Economics↗

USGS2018

Ecosystem service flows from a migratory species: Spatial subsidies of the northern pintail

Migratory species provide important benefits to society, but their cross-border conservation poses serious challenges. By quantifying the economic value of ecosystem services (ESs) provided across a species’ range and ecological data on a species’ habitat dependence, we estimate spatial subsidies —how different regions support ESs provided by a species across its range. We illustrate this method for migratory northern pintail ducks in North America. Pintails support over \$101 million USD annually in recreational hunting and viewing and subsistence hunting in the U.S. and Canada. Pintail breeding regions provide nearly \$30 million in subsidies to wintering regions, with the “Prairie Pothole” region supplying over \$24 million in annual benefits to other regions. This information can be used to inform conservation funding allocation among migratory regions and nations on which the pintail depends. We thus illustrate a transferrable method to quantify migratory species-derived ESs and provide information to aid in their transboundary conservation.

Ambio↗

USGS2018

Recreation economics to inform migratory species conservation: Case study of the northern pintail

Quantification of the economic value provided by migratory species can aid in targeting management efforts and funding to locations yielding the greatest benefits to society and species conservation. Here we illustrate a key step in this process by estimating hunting and birding values of the northern pintail ( Anas acuta ) within primary breeding and wintering habitats used during the species’ annual migratory cycle in North America. We used published information on user expenditures and net economic values (consumer surplus) for recreational viewing and hunting to determine the economic value of pintail-based recreation in three primary breeding areas and two primary wintering areas. Summed expenditures and consumer surplus for northern pintail viewing were annually valued at \$70M, and annual sport hunting totaled \$31M (2014 USD). Expenditures for viewing (\$42M) were more than twice as high than those for hunting (\$18M). Estimates of consumer surplus, defined as the amount consumers are willing to pay above their current expenditures, were $15M greater for viewing (\$28M) than for hunting (\$13M). We discovered substantial annual consumer surplus (\$41M) available for pintail conservation from birders and hunters. We also found spatial differences in economic value among the primary regions used by pintails, with viewing generally valued more in breeding regions than in wintering regions and the reverse being true for hunting. The economic value of pintail-based recreation in the Western wintering region (\$26M) exceeded that in any other region by at least a factor of three. Our approach of developing regionally explicit economic values can be extended to other taxonomic groups, and is particularly suitable for migratory game birds because of the availability of large amounts of data. When combined with habitat-linked population models, regionally explicit values could inform development of more effective conservation finance and policy mechanisms to enhance environmental management and societal benefits across the geographically dispersed areas used by migratory species.

Journal of Environmental Management↗

USGS2015

Optimal population prediction of sandhill crane recruitment based on climate-mediated habitat limitations

Prediction is fundamental to scientific enquiry and application; however, ecologists tend to favour explanatory modelling. We discuss a predictive modelling framework to evaluate ecological hypotheses and to explore novel/unobserved environmental scenarios to assist conservation and management decision-makers. We apply this framework to develop an optimal predictive model for juvenile (<1 year old) sandhill crane Grus canadensis recruitment of the Rocky Mountain Population (RMP). We consider spatial climate predictors motivated by hypotheses of how drought across multiple time-scales and spring/summer weather affects recruitment. Our predictive modelling framework focuses on developing a single model that includes all relevant predictor variables, regardless of collinearity. This model is then optimized for prediction by controlling model complexity using a data-driven approach that marginalizes or removes irrelevant predictors from the model. Specifically, we highlight two approaches of statistical regularization, Bayesian least absolute shrinkage and selection operator (LASSO) and ridge regression. Our optimal predictive Bayesian LASSO and ridge regression models were similar and on average 37% superior in predictive accuracy to an explanatory modelling approach. Our predictive models confirmed a priori hypotheses that drought and cold summers negatively affect juvenile recruitment in the RMP. The effects of long-term drought can be alleviated by short-term wet spring–summer months; however, the alleviation of long-term drought has a much greater positive effect on juvenile recruitment. The number of freezing days and snowpack during the summer months can also negatively affect recruitment, while spring snowpack has a positive effect. Breeding habitat, mediated through climate, is a limiting factor on population growth of sandhill cranes in the RMP, which could become more limiting with a changing climate (i.e. increased drought). These effects are likely not unique to cranes. The alteration of hydrological patterns and water levels by drought may impact many migratory, wetland nesting birds in the Rocky Mountains and beyond. Generalizable predictive models (trained by out-of-sample fit and based on ecological hypotheses) are needed by conservation and management decision-makers. Statistical regularization improves predictions and provides a general framework for fitting models with a large number of predictors, even those with collinearity, to simultaneously identify an optimal predictive model while conducting rigorous Bayesian model selection. Our framework is important for understanding population dynamics under a changing climate and has direct applications for making harvest and habitat management decisions.

Journal of Animal Ecology↗

USGS2014

Replacement cost valuation of Northern Pintail ( Anas acuta ) subsistence harvest in Arctic and sub-Arctic North America

Migratory species provide economically beneficial ecosystem services to people throughout their range, yet often, information is lacking about the magnitude and spatial distribution of these benefits at regional scales. We conducted a case study for Northern Pintails (hereafter pintail) in which we quantified regional and sub-regional economic values of subsistence harvest to indigenous communities in Arctic and sub-Arctic North America. As a first step, we used the replacement cost method to quantify the cost of replacing pintail subsistence harvest with the most similar commercially available protein (chicken). For an estimated annual subsistence harvest of ˜15,000 pintail, our mean estimate of the total replacement cost was ˜$63,000 yr −1 ($2010 USD), with sub-regional values ranging from \$263 yr −1 to \$21,930 yr −1 . Our results provide an order-of-magnitude, conservative estimate of one component of the regional ecosystem-service values of pintails, providing perspective on how spatially explicit values can inform migratory species conservation.

Human Dimensions of Wildlife: An International Jou↗