Lindberg M.S.,University of Alaska Fairbanks |
Schmidt J.H.,National Park Service |
Walker J.,Ducks Unlimited Inc.
Journal of Wildlife Management | Year: 2015
We examined changes in the pathways used for inference in The Journal of Wildlife Management (JWM) and 2 other applied journals during recent decades. Although null hypothesis significance testing is still the main approach to inference, use of information-theoretic approaches based on Akaike's Information Criterion (AIC) has rapidly grown to be a common form of inference in JWM and related journals. We observed little growth in the use of other information criteria such as Bayesian Information Criterion (BIC). The use of information criteria for multimodel inference has addressed some of the criticisms of significance testing. However, information criteria still needs to be used appropriately with a priori hypotheses to be valid. In addition, much work remains to be done on application of information criteria to more complex models such as hierarchical and Bayesian models. © 2015 The Wildlife Society.
News Article | March 2, 2017
PHILADELPHIA--(BUSINESS WIRE)--Axalta Coating Systems (NYSE: AXTA), a leading global supplier of liquid and powder coatings, and a proud partner and supporter of Ducks Unlimited Inc. and Ducks Unlimited de México (DUMAC), participated in a two-day field and classroom experience in Celestun, Yucatan, Mexico in February. The purpose of the trip was to witness first-hand the challenges facing mangrove conservation and the subsequent restoration work conducted by DUMAC. Sustainability and environmental responsibility are at the core of Axalta’s mission. Through the “Mangrove Experience,” several Axalta employees gained a better understanding of why it is critical for Axalta to continue to support these efforts, and for other companies to become involved. The Mangrove Experience curriculum is part of DUMAC’s Programa Reserva conducted at its educational center in the Yucatan. Established in 1989, the Programa Reserva has provided more than 550 representatives from government agencies, universities, and non-governmental organizations throughout Latin America with educational resources related to conservation which they have taken back and applied to enhance conservation projects in their home countries. “Mexico accounts for about six percent of the world’s remaining wetlands, approximately 8.2 million acres. Unfortunately, more than 36 percent of the world’s wetlands have been lost in the last 100 years, primarily due to human activities,” said DUMAC Executive Director Eduardo Carrera. “DUMAC has restored and enhanced more than 1.5 million acres throughout Mexico in areas that are important for wintering waterfowl and other wetland-dependent species. With partners like Axalta, we can continue to do this work well into the future.” The “Mangrove Experience” included a boat trip to the Celestun estuary and a hike through red, black, white, and buttonwood mangroves to promote a greater awareness of how the plant grows and why it is essential to conserve mangrove wetlands. Mangroves play a vital role in the ecosystem by protecting coastal areas from flooding, providing habitats for marine and other wildlife, and by supporting managed tourism which can help the economy. “It was a wonderful experience that helped put DUMAC’s mangrove conservation into perspective,” said Rodrigo Tajonar, Human Resources and Corporate Affairs Director, Axalta Latin America. “Seeing the threats facing mangroves helped the group understand how vital this conservation effort is and how Axalta directly benefits the wildlife and water quality in Mexico.” DUMAC has classified 27 million acres of wetlands and uplands as part of its Wetlands Inventory Program and 28 key wetlands for waterfowl in Mexico are included in the Ducks Unlimited Continental Conservation Plan. Axalta became a corporate partner with Ducks Unlimited in 2015 through a multi-year wetlands conservation program. “Axalta is committed to its partnership with Ducks Unlimited and DUMAC, and we offer our enthusiastic support for wetlands conservation throughout North America and Mexico,” said Regina M. Tracy, Head of Axalta’s Global Corporate Social Responsibility. “Sustainability is fundamental to our business and we are proud to support and witness the work that DUMAC and Ducks Unlimited do each day.” About Ducks Unlimited Inc. and Ducks Unlimited de Mexico Ducks Unlimited Inc., established in 1937, is the world's largest nonprofit organization dedicated to conserving North America's continually disappearing waterfowl habitats. Ducks Unlimited de Mexico was established in 1974 to carry on that work in Mexico. Ducks Unlimited has conserved more than 13.8 million acres across North America thanks to contributions from more than a million supporters. Guided by science and dedicated to program efficiency, the Ducks Unlimited organizations work toward the shared vision of wetlands sufficient to fill the skies with waterfowl today, tomorrow and forever. For more information on our work, visit www.ducks.org. Axalta is a leading global company focused solely on coatings and providing customers with innovative, colorful, beautiful and sustainable solutions. From light OEM vehicles, commercial vehicles and refinish applications to electric motors, buildings and pipelines, our coatings are designed to prevent corrosion, increase productivity and enable the materials we coat to last longer. With more than 150 years of experience in the coatings industry, the 12,800 people of Axalta continue to find ways to serve our 100,000+ customers in 130 countries better every day with the finest coatings, application systems and technology. For more information visit axalta.com and follow us @axalta on Twitter and on LinkedIn.
Cramer D.M.,University of Delaware |
Castelli P.M.,Nacote Creek Research Station |
Yerkes T.,Ducks Unlimited Inc. |
Williams C.K.,University of Delaware
Journal of Wildlife Management | Year: 2012
Midwinter waterfowl survey data indicates a long-term decline in the number of wintering American black ducks (Anas rubripes), potentially due to habitat limitations. In order for future estimates of carrying capacity to be determined, it is critical that regional food availability is estimated. We collected pairs of habitat core samples (n = 510) from 5 habitat types in southern New Jersey, USA, during October, January, and April 2006-2008 to estimate resource availability and variability. We collected upper gastrointestinal tracts from hunter-killed birds (n = 45) and late season collections (n = 19) to identify food items and limited our estimates of resource availability to only winter food items; thereby reducing the availability of seed foods found in our core samples by 38% and animal foods by 96%. We did not detect differences in years or sampling period, but did between habitat types. Mudflat habitat had the greatest availability of invertebrate and vertebrate food items and appeared to supply the bulk of energy to black ducks wintering in southern New Jersey. We suggest conservation efforts to be focused on restoring or enhancing mudflat habitat as an integral component of an ecologically functioning salt marsh to increase food availability. © 2011 The Wildlife Society. Copyright © The Wildlife Society, 2011.
Peron G.,Colorado State University |
Peron G.,U.S. Geological Survey |
Walker J.,Ducks Unlimited Inc. |
Rotella J.,Montana State University |
And 2 more authors.
Ecology | Year: 2014
Birds and their population dynamics are often used to understand and document anthropogenic effects on biodiversity. Nest success is a critical component of the breeding output of birds in different environments; but to obtain the complete picture of how bird populations respond to perturbations, we also need an estimate of nest abundance or density. The problem is that raw counts generally underestimate actual nest numbers because detection is imperfect and because some nests may fail or fledge before being subjected to detection efforts. Here we develop a state-space superpopulation capture-recapture approach in which inference about detection probability is based on the age at first detection, as opposed to the sequence of re-detections in standard capture-recapture models. We apply the method to ducks in which (1) the age of the nests and their initiation dates can be determined upon detection and (2) the duration of the different stages of the breeding cycle is a priori known. We fit three model variants with or without assumptions about the phenology of nest initiation dates, and use simulations to evaluate the performance of the approach in challenging situations. In an application to Blue-winged Teal Anas discors breeding at study sites in North and South Dakota, USA, nesting stage (egg-laying or incubation) markedly influenced nest survival and detection probabilities. Two individual covariates, one binary covariate (presence of grazing cattle at the nest site), and one continuous covariate (Robel index of vegetation), had only weak effects. We estimated that 5-10% of the total number of nests were available for detection but were missed by field crews. An additional 6-15% were never available for detection. These percentages are expected to be larger in less intense, more typical sampling designs. User-friendly software nestAbund is provided to assist users in implementing the method. © 2014 by the Ecological Society of America.
Johnson F.A.,U.S. Geological Survey |
Case D.J.,DJ Case and Associates |
Humburg D.D.,Ducks Unlimited Inc.
Wildlife Society Bulletin | Year: 2016
The most recent revision of the North American Waterfowl Management Plan seeks to increase the adaptive capacity of the management enterprise to cope with accelerating changes in climate, land-use patterns, agency priorities, and the waterfowl and wetlands constituency. Institutional and cultural changes of the magnitude envisioned are necessarily slow, messy processes, involving many actors who at a minimum must agree on the need for change. Waterfowl conservation now finds itself in the transition zone between business as usual and some new mode of operation. There are at least 2 different perspectives of this transition: one focuses on process, accountability, and planning for change; another focuses on solutions generated from an organic process of creativity, information sharing, and risk-taking. Both of these views have something to contribute, but some in the wildlife management enterprise may tend to focus more on the first view. We suggest that ideas from panarchy theory, especially those related to the behaviors of complex adaptive systems, can help waterfowl managers better understand and foster the institutional changes they seek. © 2016 The Wildlife Society. © The Wildlife Society, 2016
Humburg D.D.,Ducks Unlimited Inc. |
Anderson M.G.,Institute for Wetland and Waterfowl Research
Wildfowl | Year: 2014
The North American Waterfowl Management Plan (NAWMP) is a continental ecosystems model for wildlife conservation planning with worldwide implications. Since established in 1986, NAWMP has undergone continual evolution as challenges to waterfowl conservation have emerged and information available to support conservation decisions has become available. In the 2012 revision, the waterfowl management community revisited the fundamental basis for the Plan and placed greater emphasis on sustaining the Plan's conservation work and on integration across disciplines of harvest and habitat management. Most notably, traditional and nontraditional users (i.e. hunters and wildlife viewers) of the resource and other conservation supporters are integrated into waterfowl conservation planning. Challenges ahead for the waterfowl management enterprise include addressing tradeoffs that emerge when habitat for waterfowl populations versus habitat for humans are explicitly considered, how these objectives and decision problems can be linked at various spatial and temporal scales, and most fundamentally how to sustain NAWMP conservation work in the face of multi-faceted ecological and social change. © Wildfowl & Wetlands Trust.
Evans-Peters G.R.,04 Nash Hall |
Dugger B.D.,04 Nash Hall |
Petrie M.J.,Ducks Unlimited Inc.
Wetlands | Year: 2012
The Wetland Reserve Program (WRP) is one conservation tool used to mitigate national wetland loss, but few studies have evaluated the WRP for wildlife. During falls 2008 and 2009, we evaluated wetland plant communities and seed densities on 23 WRP wetlands in relation to 23 reference wetlands on managed public lands in the Willamette Valley and Lower Columbia River Valley (LCRV) of western Oregon and southwest Washington. Plant community on WRP easements differed by management intensity (A00.111, p00.002) with perennial and introduced species indicative of unmanaged easements and annuals indicative of actively managed wetlands, but plant community composition did not differ between WRP and reference wetlands (A00.003, p00.21). Overall, seed biomass was similar between WRP and reference wetlands (F1, 4102.44, p00.12), but this relationship varied by study region (F1, 41012.6, p00.001) related to management intensity. Seed biomass was greater on actively (765±105 kg/ha) vs. passively (349±105 kg/ha) managed sites (F3, 3409.90, p00.003). Seasonal wetlands on WRP easements can achieve a structure and function similar to reference sites. However, we suspect that in the absence of active management the value of WRP sites will decline as the plant community shifts to being dominated by introduced perennial species like reed-canary grass that will reduce the diversity of native wetland plants and lower seed abundance for waterbirds. © Society of Wetland Scientists 2012.
Plattner D.M.,Southern Illinois University Carbondale |
Eichholz M.W.,Southern Illinois University Carbondale |
Yerkes T.,Ducks Unlimited Incorporated
Journal of Wildlife Management | Year: 2010
A bioenergetic approach has been adopted as a planning tool to set habitat management objectives by several United States Fish and Wildlife Service North American Waterfowl Management Plan Joint Ventures. A bioenergetics model can be simplified into 2 major components, energetic demand and energetic supply. Our goal was to estimate habitat-specific food availability, information necessary for estimating energy supply for black ducks (Anas rubripes) wintering on Long Island, New York, USA. We collected both nektonic and benthic samples from 85 wetland sites dispersed among 5 habitat types (salt marsh, mud flat, submersed aquatic vegetation, brackish bay, and freshwater) commonly used by black ducks in proportion to expected use. Biomass varied among habitats (F4,5 > 7.46, P < 0.03) in 20042005, but there was only marginal variation in 20052006 (F3,4 =5.75, P =0.06). Mud flats had the greatest biomass (1,204 kg/ha, SE 532), followed by submersed aquatic vegetation (61 kg/ha, SE 18), and salt marsh (34 kg/ha, SE =6). In the second year of the study, freshwater had the greatest biomass (306 kg/ha, SE =286), followed by mud flats (85 kg/ha, SE =63), and salt marsh (35 kg/ha, SE =4). Our results suggest food density on wintering grounds of black ducks on coastal Long Island is considerably lower than for dabbling ducks using inland freshwater habitats, indicating black duck populations are more likely than other species of dabbling ducks to be limited by winter habitat. We recommend targeting preservation, restoration, and enhancement efforts on salt marsh habitat. © 2010 The Wildlife Society.
Smith A.,Ducks Unlimited Inc
Journal of Spatial Science | Year: 2010
This paper describes an approach to using the Random Forest classification algorithm to quantitatively evaluate a range of potential image segmentation scale alternatives in order to identify the segmentation scale(s) that best predict land cover classes of interest. The image segmentation scale selection process was used to identify three critical image object scales that when combined produced an optimal level of land cover classification accuracy. Following segmentation scale optimization, the Random Forest classifier was then used to assign land cover classes to 11 scenes of SPOT satellite imagery in North and South Dakota with an average overall accuracy of 85.2 percent. © 2010 Surveying and Spatial Sciences Institute and Mapping Sciences Institute, Australia.
Rashford B.S.,University of Wyoming |
Walker J.A.,Ducks Unlimited Inc. |
Bastian C.T.,University of Wyoming
Conservation Biology | Year: 2011
Much of the remaining grassland, particularly in North America, is privately owned, and its conversion to cultivated cropland is largely driven by economics. An understanding of why landowners convert grassland to cropland could facilitate more effective design of grassland-conservation programs. We built an empirical model of land-use change in the Prairie Pothole Region (north-central United States) to estimate the probability of grassland conversion to alternative agricultural land uses, including cultivated crops. Conversion was largely driven by landscape characteristics and the economic returns of alternative uses. Our estimate of the probability of grassland conversion to cultivated crops (1.33% on average from 1979 to 1997) was higher than past estimates (0.4%). Our model also predicted that grassland-conversion probabilities will increase if agricultural commodity prices continue to follow the trends observed from 2001 to 2006 (0.93% probability of grassland conversion to cultivated crops in 2006 to 1.5% in 2011). Thus, nearly 121 million ha (30 million acres) of grassland could be converted by 2011. Conversion probabilities, however, are spatially heterogeneous (range 0.2% to 3%), depending on characteristics of a parcel (e.g., soil quality and economic returns). Grassland parcels with relatively high-quality land for agricultural production are more likely to be converted to cultivated crops than lower-quality parcels and are more responsive to changes in the economic returns on alternative agricultural land uses (i.e., conversion probability increases by a larger magnitude for high-quality parcels when economics returns to alternative uses increase). Our results suggest that grassland conservation programs could be proactively targeted toward high-risk parcels by anticipating changes in economic returns, such as could occur if a new biofuel processing plant were to be built in an area. ©2010 Society for Conservation Biology.