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At least 649 records · Page 36Linked to original sources
USGS1984

Refuge management analyses: research needs for Muscatatuck National Wildlife Refuge

Muscatatuck National Wildlife Refuge, located in southeastern Indiana, was established by the Migratory Bird Conservation Commission in 1966. Land use planning for the Refuge formally began in 1971, and development of facilities designed in that planning effort is now nearing completion. As these facilities become operational, Refuge personnel will be manipulating water (both spatially and temporally) and other habitat components to achieve the joint Refuge goals of natural resource conservation and public use. This situation offers a unique opportunity to institute research and management studies designed to evaluate and enhance the effectiveness of the management regime in providing for the needs of migratory waterfowl and other wildlife resources.

Indiana↗
USGS1984

Refuge management analyses: levee alternatives at Clarence Cannon National Wildlife Refuge

This report documents the results of a workshop that examined levee alternatives at Clarence Cannon National Wildlife Refuge. This refuge is located along the Mississippi River, approximately 50 miles north of St. Louis. It was purchased primarily for waterfowl maintenance. A levee providing flood protection from the Mississippi River has broken four times since the Refuge was acquired in 1965. A number of alternatives have been proposed in response to the most recent break in 1983. Long term alternatives considered at the workshop included: Improve the existing levee by raising the height approximately 2 ft. Improve the existing levee by raising the height approximately 2 ft. Maintain the levee at a lower elevation by including a spillway about 3 ft lower than the existing levee height. Do not maintain a levee so that the Refuge will flood directly with river stage. Repair of the major breaks in the levee, but not the more general wave damage, was considered as a short term alternative. Participants first specified the habitats and management controls desired at Clarence Cannon National Wildlife Refuge. These were centered around attaining the maximum feasible development and management of moist soil units. Levee alternatives were evaluated in terms of their ability to provide the desired habitats and management controls. Preliminary cost estimates were prepared for each alternative, and the qualitative consequences of each alternative identified for the full set of outputs from the Refuge Master Plan. The alternative of improving the existing levee by raising the height was unanimously preferred on purely “biological” grounds (with cost not considered). Repairing the levee with no change in elevation was unanimously selected as the most cost effective alternative.

Missouri↗
USGS1988

Effects of aircraft noise and sonic booms on domestic animals and wildlife: bibliographic abstracts

The purpose of this document is to provide an information base on the effects of aircraft noise and sonic booms on various animal species. Such information is necessary to assess potential impacts to wildlife populations from proposed military and other flight operations. To develop this document the National Ecology Center conducted a literature search of information pertaining to animals and wildlife. Information concerning other types of noise was also gathered to supplement the lack of knowledge on the effects of aircraft noise. The bibliographic abstracts in this report provide a compilation of current knowledge. No attempt was made to evaluate the appropriateness or adequacy of the scientific approach of each study.

Report↗
USGS1990

Evaluation of wildlife-habitat relationships data base for predicting bird community composition in central California chaparral and blue oak woodlands

The California Wildlife-Habitat Relationships (WHR) database can be used to assist resource managers to evaluate effects of habitat manipulations on wildlife. The accuracy of predictions from WHR was evaluated using data from bird surveys conducted during winter and spring 1984 and 1985 in chamise ( Adenostema fasciculata ) chaparral, mixed chaparral and blue oak ( Quercus douglasii ) woodland. Considerable variability between habitat types was found for errors both of commission and of omission.

California↗
USGS2012

Examining wildlife responses to phenology and wildfire using a landscape-scale camera trap network

Between 2001 and 2009, the Borderlands Jaguar Detection Project deployed 174 camera traps in the mountains of southern Arizona to record jaguar activity. In addition to jaguars, the motion-activated cameras, placed along known wildlife travel routes, recorded occurrences of ~ 20 other animal species. We examined temporal relationships of white-tailed deer (Odocoileus virginianus) and javelina (Pecari tajacu) to landscape phenology (as measured by monthly Normalized Difference Vegetation Index data) and the timing of wildfire (Alambre Fire of 2007). Mixed model analyses suggest that temporal dynamics of these two species were related to vegetation phenology and natural disturbance in the Sky Island region, information important for wildlife managers faced with uncertainty regarding changing climate and disturbance regimes.

Arizona↗
USGS2006

Riparian willow restoration at Arapaho National Wildlife Refuge

Riparian willow communities along the Illinois River at Arapaho National Wildlife Refuge in North Park near Walden, Colorado, provide important habitat for a number of wildlife species, including neotropical migratory birds. Existing stands in the northern (downstream) portion of the refuge are sparse and discontinuous (Photo 1) compared to upstream portions of the Illinois River and the parallel Michigan River.

The Green Line, Colorado Riparian Association News↗
USGS1999

Fishes of Missouri River, chute, and flood plain habitats: Chapter 4 in Initial biotic survey of Lisbon Bottom, Big Muddy National Fish and Wildlife Refuge

The Lisbon Bottom Unit of the Big Muddy National Fish and Wildlife Refuge (Refuge) is approximately 2,200 acres and is the first complete unit of the Refuge. Primary objectives of the Refuge are to create and restore diverse riverine aquatic habitats and reconnect the Missouri River to its flood plain where feasible. Management seeks to accomplish these objectives by encouraging natural processes of erosion, deposition, and succession to the greatest extent possible. One of the most salient aquatic features of the Lisbon Bottom Unit is a newly created 2-mile-long free-flowing chute, or side channel (Fig. 1). This chute began forming as a levee breech scour hole during the Great Flood of 1993. The chute continued to develop during the 1995 flood and finally cut through to a flowing side channel during the 1996 flood. Extensive erosion and bank sluffing continued during 1997 due to sustained high flows that occurred throughout most of the year. The chute has progressively become wider and deeper with a developing meander pattern and channel bars have begun to form. Lisbon Bottom also contains several seasonal and permanent wetlands and is subject to periodic flooding at high Missouri River stages. Eight studies have been completed or are ongoing to evaluate Missouri River fishes associated with various habitat components of Lisbon Bottom and adjacent Missouri River reaches (Table 1). Several are part of much larger investigations to evaluate fish use of flood-created habitat features, basinwide fish assessment, and endangered or candidate species concerns. At the Lisbon Bottom Unit or in the Missouri River adjacent to the unit 54 fish species were collected (Table 2). Eight of these species have either a protected status under State or Federal laws or biologists consider them to potentially qualify for protected status. The status of the following fish is listed in Table 2: pallid sturgeon x shovelnose sturgeon hybrid, paddlefish, northern pike, sturgeon chub, sicklefin chub, ghost shiner, western silvery minnow, plains minnow, and blue sucker. Equally important to note are fish species that were not collected. The flathead chub, currently listed as State endangered and proposed for Federal listing, were not collected in any of the studies. Common fish species, collected in all seven sampling studies, included gizzard shad, common carp, river carpsucker, and freshwater drum. Paddlefish, skipjack herring, silver carp, white sucker, redfin shiner, western silvery minnow, bullhead minnow, and black bullhead were each collected in only one of the seven studies. Pflieger (1971) developed a guild system for the fishes of Missouri based on distribution patterns and centers of abundance. Fish were assigned to one of four primary faunal groups: Ozark, Big River, Lowland, and Prairie. Two secondary groups (Ozark-prairie and Ozark-lowland) were defined for species equally abundant and distributed in two of the primary areas. Two Ozark-prairie species, shorthead redhorse and white sucker, were collected on or near the Lisbon Bottom Unit. Big River species are found primarily in the Missouri and Mississippi Rivers. The environmental factors controlling fish distribution in these rivers appear to be substrate, current velocity, and turbidity. On or near the Lisbon Bottom Unit 18 Big River species were collected (Table 2). Lowland species are intolerant of siltation and high turbidity. They inhabit standing or slow-moving water with sand, fine gravel, and organic debris substrates. Two Lowland species, bullhead minnow and mosquitofish, were collected in connected scours on the Lisbon Bottom Unit. Prairie species have broader ecological tolerances than the Ozark and Lowland species. They are largely absent in high gradient streams and cool, clear waters. Prairie species make up a significant proportion of Missouri and Mississippi River fishes. Seven Prairie species were collected on or near the Lisbon Bottom Unit (Table 2). The last group, Wide-ranging, was defined as the species more widespread than the other faunal groups with broader environmental tolerances. Most Wide-ranging species occur at least occasionally in all sections of the state. Nineteen Wide-ranging species were collected on or near the Lisbon Bottom Unit (Table 2). Kubisiak (1997) found that isolated scours in the Lower Missouri River were dominated by Wide-ranging species. Connected scours also held Wideranging species but they contained Prairie species and were dominated by Big River species. Faunal group diversity and species richness were compared between isolated (Study l) and connected (Studies 4, 5, 7, and 8) scours of the Lisbon Bottom Unit. Species richness was similar with 22 species collected in isolated scours and an average of 24.8 species collected in connected scours. Isolated scour fish catches were dominated by Wide-ranging fish (59%) with 14% Big River fishes and 14% Prairie fishes. Connected scours had a larger percentage of Big River fish (32%) and fewer Wide-ranging (36%) and Prairie (13%) species than the isolated scours. In the combined studies, Wide-ranging fish dominated the connected scours. A similar comparison was made of fish from chute habitats and the Missouri River. Chute habitats include the Lisbon Bottom Chute, the chute between the right bank and island located at river mile 219, and a shallow channel running between a large sandbar complex and the channel border adjacent to Lisbon Bottom. Species richness in the chutes (35 species) was greater than that of the adjacent river (23 species). Big River species (40%) dominated the chute samples, followed by Wide-ranging at 31% Cand Prairie Cut 14%. The river samples contained equal numbers of Wide-ranging species (35%) and Big River species (35%) with 17% Prairie species. Differences in fish guild diversity and species richness may be due to numerous factors including sampling effort and sampling season. River samples were collected only in Study 3 in October; chute samples were collected in July, August, and October. Fish may have been using the chute in July and August to spawn, feed, or escape high river levels. The Lisbon Bottom Chute is a truly unique feature of the Lower Missouri River. It is the first naturally created side channel to develop since the U.S. Army Corps of Engineers tamed the river. The Corps eliminated 89% of the islands in the Missouri River between 1879 and 1954 (Funk and Robinson 1974). The chutes between the islands and the shore were shallower with less current than the main channel. These areas provided diversity to the Missouri River fish habitat, serving as nursery and feeding areas. The Lisbon Bottom Unit of the Big Muddy National Fish and Wildlife Refuge will continue to be studied in an effort to understand the complex role these areas play in river systems.

Missouri↗
USGS2017

Vegetation map for the Hakalau Forest Unit of the Big Island National Wildlife Refuge Complex on the island of Hawai‘i

This vegetation map was produced to serve as an updated habitat base for management of natural resources of the Hakalau Forest Unit (HFU) of the Big Island National Wildlife Refuge Complex (Refuge) on the island of Hawai‘i. The map is based on a vegetation map originally produced as part of the U.S. Fish and Wildlife Service’s Hawai‘i Forest Bird Survey to depict the distribution, structure, and composition of plant communities on the island of Hawai‘i as they existed in 1977. The current map has been updated to represent current conditions of plant communities in the HFU, based on WorldView 2 imagery taken in 2012 and very-high-resolution imagery collected by Pictometry International from 2010 to 2014. Thirty-one detailed plant communities are identified on this map, and fourteen of these units are found within the boundaries of HFU. Additionally, the mapped units can be displayed as five tree canopy cover units, three moisture zones units, eight dominant tree species units, and four habitat status units by choosing the various fields to group the units from the map attribute table. This updated map will provide a foundation for the refinement and tracking of management actions on the Refuge for the near future, particularly as the habitats in this area are subject to projected climate change.

Hawai'i↗
USGS2019

International Organizations and Programs for Wildlife Conservation

Historically, private non-governmental entities in the developed world took interest in wildlife in developing nations. Nineteenth and early twentieth century explorers of Africa, Asia, and South America reported fascinating encounters with magnificent species that were previously cryptic or unknown (Robinson et al. 2017). Organizations such as the Royal Geographical Society in the United Kingdom, a sponsor of Charles Darwin’s expedition, the Boone and Crockett Club in North America, and numerous museums in the United States and Europe, sponsored chronicled expeditions to remote places under the goal of discovery and collection. Concurrent with the quest for discovery of wild places and species new to science was the drive to find and secure timber, mineral, energy, and other resources to fuel the growing demands of development brought on by the Industrial Revolution (Lucas 2009, Stearns 2013). This led to exploitation, and overexploitation, which led to growing concerns over the loss of species, including species not yet known to western science. During the latter half of the twentieth century, in response to these concerns, private non-governmental organizations formed to promote conservation through science, advocacy, and technical assistance. These organizations vary from working independently, to forming collaborations across the public and private sphere. Our objective in this chapter is to outline some of the major conventions, major organizations, and programs that promote engagement in wildlife conservation and management at the international level.

Book chapter↗
USGS2019

Climate change adaptation for coastal national wildlife refuges

National Wildlife Refuges (NWRs) along the East Coast of the United States protect habitat for a host of wildlife species, while also offering storm surge protection, improving water quality, supporting nurseries for commercially important fish and shellfish, and providing recreation opportunities for coastal communities. Yet in the last century, coastal ecosystems in the eastern U.S. have been severely altered by human development activities as well as sea-level rise and more frequent extreme events related to climate change. These influences threaten the ability of NWRs to protect our nation’s natural resources and to sustain their many beneficial services. Through this project, researchers are collaborating with managers of the North Carolina Coastal Refuges Complex, Cape Romain NWR, South Carolina, and other local interested partners to assist with their long-term planning under uncertain conditions regarding sea-level rise and other global change processes. Researchers are using a variety of state-of-the-art approaches, including formal decision science for systematically analyzing management alternatives and scenario planning methods for engaging with stakeholders to explore possible futures. These approaches are aimed at helping NWR staff develop management objectives, identify and weigh potential management actions for adaptation, and generate decision-support tools and models. Outcomes and products from these efforts will aid managers as they plan for and adapt to the complex challenges facing the NWR system as changing climate and other conditions make their work increasingly more difficult.

Final Project Memorandum↗
USGS2021

Harvest as a tool to manage populations of undesirable or overabundant fish and wildlife

Harvest is a common management tool for fish and game species and can also be used for overabundant populations when stakeholders want to reduce populations reduced and still provide recreational opportunities. The authors propose a framework to determine if harvest can be used to control populations when overabundance is an issue, stakeholders support harvest, information is available to set harvest goals and evaluate impacts of harvest, and assessments are conducted to evaluate unintended consequences of harvest. The chapter provides two case examples of mid-continent light geese and blue catfish in the Chesapeake Bay watershed, for which overabundance was a problem and stakeholders had interest in harvest. Substantial data existed to set goals for light geese whereas blue catfish data were limited. For both light geese and blue catfish, desired outcomes have not yet been achieved, but hunting and fishing opportunities generated societal benefits despite existing barriers to increasing harvest. Harvest to control overabundant populations can be a useful tool, but consideration of stakeholder support, the data require to establish and monitor goals, and unintended consequences should be considered for an effective harvest plan. Harvest is a common management tool used for centuries to limit populations of game species (Caughley 1977, Redmond 1986). Managing populations using harvest regulations allow certain sizes, numbers, sex, and species to be harvested, and often include open or closed seasons. Regulated hunting opportunity and harvest are cornerstones of the North American Model of Wildlife Conservation, which developed gradually following unregulated harvest of wildlife populations that often were at risk of overharvest or extinction (Geist et al. 2001). Since then, many populations have recovered and expanded to the point where harvest regulations are now often used to limit or even reduce populations of some species. In general, harvest regulations have been well established as an effective way to control animal populations in many aquatic and terrestrial systems and are broadly accepted among the hunting and fishing public. For example, harvest regulations have been established or adapted to reduce or control populations of feral hogs (Sus scrofa; Hanson et al. 2009), white-tailed deer (Odocoileus virginianus; Simard et al. 2013) and cougar (Puma concolor; Cooley et al. 2009), overabundant small black bass (Micropertus spp.; Isermann and Paukert 2010), northern pike (Esox lucius; Pierce 2010) or non-native species (Arlinghaus et al. 2016b). Harvest has also been employed as a tool for controlling populations of invasive species. However, in many cases invasive species are so overabundant that a substantial commitment to harvest is necessary, which may exceed recreational harvest capacity and require commercial harvest or an active lethal control program by management agencies. Often removal of invasive species is challenging because the ultimate goal may be to eliminate the entire population, which may require impractical efforts. For example, controlling Asian carp in the Illinois River may require harvest rates of at least 70% (Tsehaye et al. 2013), whereas in the Great Smoky Mountains, an annual harvest rate of 40% would be necessary to decrease feral hog populations (Salinas et al. 2015). Many invasive species are known to negatively impact native species and ecosystems; thus, eradication is an ideal outcome. However, there may be opportunity to use harvest to control populations of native (or non-native) species that have some value yet are still overabundant. In this chapter, we explore the process of using harvest to control overabundant populations that have some recreational value, provide two examples to control overabundant populations using harvest, and describe the challenges and effectiveness associated with these efforts and some of the unintended effects of using harvest to control populations.

Book chapter↗
USGS2024

Climate science and adaptation planning support for State Wildlife Action Plans in the North Central region

Final report for an NC CASC project to identify needs and provide support for states in the North Central region and Idaho to integrate climate science and adaptation into their State Wildlife Action Plans (SWAPs). Our objectives were to: 1) engage with state wildlife agencies in the North Central region to identify their needs for climate-informed planning support and 2) collaboratively develop products that will help them better integrate climate adaptation strategies into SWAPs.

Colorado, Idaho, Montana, Nebraska, North Dakota, ↗
USGS1995

Wildlife mortality attributed to organophosphorus and carbamate pesticides

Organophosphorus (OP) and carbamate pesticides are used widely in agricultural and residential applications as insecticides, herbicides, fungicides, and rodenticides. This family of chemicals replaced the organochlorine pesticides banned for use in the United States in the 1970's. Unlike organochlorine pesticides, which are long-lived in the environment and cause biological damage when they accumulate in an organism's system over time, OP and carbamate pesticides are short-lived in the environment and fast-acting on their "target pest." Direct mortality of wildlife from organochlorine pesticides was uncommon (Hayes and Wayland 1975); however, mortality is the primary documented effect on wildlife from OP and carbamate pesticides (Grue et al. 1983). Organophosphorus and carbamate pesticide toxicity is not specific to a target "pest," and lethal effects are seen in nontarget organisms; birds appear to be the most sensitive class of animals affected by these pesticides. Organophosphorus and carbamate pesticides primarily affect the nervous system by inhibiting acetylcholinesterase (AChE) enzyme activity. This enzyme's main function in the nervous system is to break down the neurotransmitter acetylcholine. When AChE is altered by OP and carbamate pesticides, it cannot perform this breakdown function and acetylcholine accumulates. Acetylcholine accumulation increases nerve impulse transmission and leads to nerve exhaustion and, ultimately, failure of the nervous system. When the nervous system fails, muscles do not receive the electrical input they require to move. The respiratory muscles are the most critical muscle group affected, and respiratory paralysis is often the immediate cause of death.

Book chapter↗
USGS2021

Optimal strategies for managing wildlife harvest under climate change

Wildlife populations are experiencing shifting dynamics due to climate and landscape change. Management policies that fail to account for non‐stationary dynamics may fail to achieve management objectives. We establish a framework for understanding optimal strategies for managing a theoretical harvested population under non‐stationarity. Building from harvest theory, we develop scenarios representing changes in population growth rate ( ) or carrying capacity ( ) and derive time‐dependent optimal harvest policies using stochastic dynamic programming. We then evaluate the cost of falsely assuming stationarity by comparing the outcomes of forward projections in which either the optimal policy or a stationary policy is applied. When declines over time, the stationary policy leads to an underharvest of the population, resulting in less harvest over the short term but leaving the population in a higher‐value state. When declines over time, the stationary policy leads to overharvest, resulting in greater harvest returns in the short term but leaving the population in a lower and potentially more vulnerable state. This work demonstrates the basic properties of time‐dependent harvest management and provides a framework for evaluating the many outstanding questions about optimal management strategies under climate change. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.

Journal of Wildlife Management↗
USGS2026

Feathers and flu: Identifying data gaps in avian influenza host dynamics to prioritize wildlife conservation

Highly pathogenic avian influenza viruses (HPAIV) have had disastrous, worldwide effects on wild birds and domestic poultry since the emergence of the A/goose/Guangdong/1/1996 (Gs/GD/96) lineage. The currently circulating H5N1 clade 2.3.4.4b has an expanded set of susceptible hosts, including many migratory wild birds, and is associated with higher transmission rates, increased susceptibility among wild bird hosts, and a greater number of wildlife reservoirs. Certain wild bird life-history strategies and behaviors have been suggested to explain avian hosts’ susceptibility and exposure to HPAIV. These biological traits include gregariousness, such as colonial nesting and mixed flock foraging, predation or scavenging on wild birds, and association with aquatic habitats. Variation in host infection responses (e.g., infectability, shedding rates and duration, mortality rate, antibody development) informs the overall infection risk across avian species, yet the specific role of biological traits is often inconsistent and unclear across taxa. Moreover, the interactions and potential compounding effects among these biological traits remain largely unknown. To develop a more holistic understanding of cumulative risk across bird species, we integrate existing information on infection risk factors (i.e., susceptibility, immunological response, and behavioral traits) into a qualitative multivariate analysis. This approach enabled us to examine how infection risk factors relate to biological traits (e.g., phylogeny, physiology, behavior, species range) and to begin disentangling their complex interactions. We quantified and summarized these risk factors across host species and qualitatively ranked species by their viral responses along a proposed HPAIV response continuum, guided by expectations of traits and metrics associated with competence or vulnerability to HPAIV. In doing so, we aimed to better understand how viral responses and biological traits synergistically interact to influence cumulative risk across wild bird species. This work broadly expands on the previous avian influenza literature, which has focused on Anseriformes and Charadriiformes as primary viral reservoirs. We tie our findings to effective disease management responses with links to risk components, including descriptions of potential surveillance strategies applied to research and One Health goals, as well as a fuller understanding of how resources may be better deployed for rapid response when spillovers do inevitably occur. Additionally, we identified numerous areas where vital epidemiological information is lacking to best characterize the spread of these viruses. Ultimately, this improved understanding will help identify and inform disease management needs and decision making.

Wildlife Monographs↗
USGS2013

Accuracy of aging ducks in the U.S. Fish and Wildlife Service Waterfowl Parts Collection Survey

The U.S. Fish and Wildlife Service conducts an annual Waterfowl Parts Collection Survey to estimate composition of harvested waterfowl by species, sex, and age (i.e., juv or ad). The survey relies on interpretation of duck wings by a group of experienced biologists at annual meetings (hereafter, flyway wingbees). Our objectives were to estimate accuracy of age assignment at flyway wingbees and to explore how accuracy rates may influence bias of age composition estimates. We used banded mallards (Anas platyrhynchos; n = 791), wood ducks (Aix sponsa; n = 242), and blue-winged teal (Anas discors; n = 39) harvested and donated by hunters as our source of birds used in accuracy assessments. We sent wings of donated birds to wingbees after the 2002–2003 and 2003–2004 hunting seasons and compared species, sex, and age determinations made at wingbees with our assessments based on internal and external examination of birds and corresponding banding records. Determinations of species and sex of mallards, wood ducks, and blue-winged teal were accurate (>99%). Accuracy of aging adult mallards increased with harvest date, whereas accuracy of aging juvenile male wood ducks and juvenile blue-winged teal decreased with harvest date. Accuracy rates were highest (96% and 95%) for adult and juvenile mallards, moderate for adult and juvenile wood ducks (92% and 92%), and lowest for adult and juvenile blue-winged teal (84% and 82%). We used these estimates to calculate bias for all possible age compositions (0–100% proportion juv) and determined the range of age compositions estimated with acceptable levels of bias. Comparing these ranges with age compositions estimated from Parts Collection Surveys conducted from 1961 to 2008 revealed that mallard and wood duck age compositions were estimated with insignificant levels of bias in all national surveys. However, 69% of age compositions for blue-winged teal were estimated with an unacceptable level of bias. The low preliminary accuracy rates of aging blue-winged teal based on our limited sample suggest a more extensive accuracy assessment study may be considered for interpreting age compositions of this species.

Wildlife Society Bulletin↗
USGS2011

Rapid assessment of rice seed availability for wildlife in harvested fields

Rice seed remaining in commercial fields after harvest (waste rice) is a critical food resource for wintering waterfowl in rice-growing regions of North America. Accurate and precise estimates of the seed mass density of waste rice are essential for planning waterfowl wintering habitat extents and management. In the Sacramento Valley of California, USA, the existing method for obtaining estimates of availability of waste rice in harvested fields produces relatively precise estimates, but the labor-, time-, and machineryintensive process is not practical for routine assessments needed to examine long-term trends in waste rice availability. We tested several experimental methods designed to rapidly derive estimates that would not be burdened with disadvantages of the existing method. We first conducted a simulation study of the efficiency of each method and then conducted field tests. For each approach, methods did not vary in root mean squared error, although some methods did exhibit bias for both simulations and field tests. Methods also varied substantially in the time to conduct each sample and in the number of samples required to detect a standard trend. Overall, modified line-intercept methods performed well for estimating the density of rice seeds. Waste rice in the straw, although not measured directly, can be accounted for by a positive relationship with density of rice on the ground. Rapid assessment of food availability is a useful tool to help waterfowl managers establish and implement wetland restoration and agricultural habitat-enhancement goals for wintering waterfowl. ?? 2011 The Wildlife Society.

Wildlife Society Bulletin↗