Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia
Guoping Tang, Sarah L. Shafer, Patrick J. Barlein, Justin O. Holman
2009, Ecological Modelling (220) 1481-1491
Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data...
Dynamic multistate site occupancy models to evaluate hypotheses relevant to conservation of Golden Eagles in Denali National Park, Alaska
Julien Martin, Carol L. McIntyre, James E. Hines, James D. Nichols, Joel A. Schmutz, Margaret C. MacCluskie
2009, Biological Conservation (142) 2726-2731
The recent development of multistate site occupancy models offers great opportunities to frame and solve decision problems for conservation that can be viewed in terms of site occupancy. These models have several characteristics (e.g., they account for detectability) that make them particularly well suited for addressing management and conservation problems....
Does influenza A affect body condition of wild mallard ducks, or vice versa?
Paul L. Flint, J. Christian Franson
2009, Proceedings of the Royal Society B: Biological Sciences (276) 2345-2346
Low pathogenic avian influenza (LPAI) viruses are well documented to circulate within wild waterfowl populations (Olsen et. al. 2006). It has been assumed that these infections are benign with no subsequent effects on life-history parameters. The study by Latorre-Margalef et al. (2009; hereafter L.-M. et al.) represents an important step,...
Avian influenza at both ends of a migratory flyway: characterizing viral genomic diversity to optimize surveillance plans for North America
John M. Pearce, Andrew M. Ramey, Paul L. Flint, Anson V. Koehler, Joseph P. Fleskes, J. Christian Franson, Jeffrey S. Hall, Dirk V. Derksen, S. Ip
2009, Evolutionary Applications (2) 457-468
Although continental populations of avian influenza viruses are genetically distinct, transcontinental reassortment in low pathogenic avian influenza (LPAI) viruses has been detected in migratory birds. Thus, genomic analyses of LPAI viruses could serve as an approach to prioritize species and regions targeted by North American surveillance activities for foreign origin...
Geographic extent and chronology of the invasion of non-native lionfish (Pterois volitans [Linnaeus 1758] and P. miles [Bennett 1828]) in the Western North Atlantic and Caribbean Sea
Pamela J. Schofield
2009, Aquatic Invasions (4) 473-479
The Indo-Pacific lionfishes (Pterois volitans [Linnaeus 1758] and P. miles [Bennett 1828]: Family Scorpaenidae) are the first non-native marine fishes to establish in the Western North Atlantic. The chronology of the invasion is reported here using records from the US Geological Survey's Nonindigenous Aquatic Species database. Currently, lionfish are established...
An improved procedure for detection and enumeration of walrus signatures in airborne thermal imagery
Douglas M. Burn, Mark S. Udevitz, Suzann G. Speckman, R. Bradley Benter
2009, International Journal of Applied Earth Observation and Geoinformation (11) 324-333
In recent years, application of remote sensing to marine mammal surveys has been a promising area of investigation for wildlife managers and researchers. In April 2006, the United States and Russia conducted an aerial survey of Pacific walrus (Odobenus rosmarus divergens) using thermal infrared sensors to detect groups of animals...
Impacts of forest fragmentation on species richness: A hierarchical approach to community modelling
Elise F. Zipkin, Amielle DeWan, J. Andrew Royle
2009, Journal of Applied Ecology (46) 815-822
1. Species richness is often used as a tool for prioritizing conservation action. One method for predicting richness and other summaries of community structure is to develop species-specific models of occurrence probability based on habitat or landscape characteristics. However, this approach can be challenging for rare or elusive species for...
Bayesian inference in camera trapping studies for a class of spatial capture-recapture models
J. Andrew Royle, K. Ullas Karanth, Arjun M. Gopalaswamy, N. Samba Kumar
2009, Ecology (90) 3233-3244
We develop a class of models for inference about abundance or density using spatial capture-recapture data from studies based on camera trapping and related methods. The model is a hierarchical model composed of two components: a point process model describing the distribution of individuals in space (or their home range...
A cautionary note on substituting spatial subunits for repeated temporal sampling in studies of site occupancy
William L. Kendall, Gary C. White
2009, Journal of Applied Ecology (46) 1182-1188
1. Assessing the probability that a given site is occupied by a species of interest is important to resource managers, as well as metapopulation or landscape ecologists. Managers require accurate estimates of the state of the system, in order to make informed decisions. Models that yield estimates of occupancy, while...
Critical steps for the continuing advancement of hydrogeophysics
Ty P A Ferre, Laurence Bentley, Andrew Binley, Niklas Linde, Andreas Kemna, Kamini Singha, K. Holliger, J. A. Huisman, Burke J. Minsley
2009, Eos Science News (90) 200-202
Special hydrogeophysics issues published by hydrology and geophysics journals, special sessions and workshops at conferences, and an increasing number of short courses demonstrate the growing interest in the use of geophysics for hydrologic investigations. The formation of the hydrogeophysics technical subcommittee of AGU's Hydrology section adds further evidence of the...
Identifying baldcypress-water tupelo regeneration classes in forested wetlands of the Atchafalaya Basin, Louisiana
Stephen P. Faulkner, Prajwol Bhattarai, Yvonne C. Allen, John A. Barras, Glenn C. Constant
2009, Wetlands (29) 809-817
Baldcypress-water tupelo (cypress-tupelo) swamps are critically important coastal forested wetlands found throughout the southeastern U.S. The long-term survival and sustainability of these swamp forests is unknown due to large-scale changes in hydrologic regimes that prevent natural regeneration following logging or mortality. We used NWI wetland maps and remotely sensed hydrologic...
Regional economic analysis of current and proposed management alternatives for Rappahannock River Valley National Wildlife Refuge
Lynne Koontz, Natalie Sexton, Ryan Donovan
2009, Open-File Report 2009-1247
The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan. The Comprehensive Conservation Plan must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes....
Salamander occupancy in headwater stream networks
E.H.C. Grant, L.E. Green, W.H. Lowe
2009, Freshwater Biology (54) 1370-1378
1. Stream ecosystems exhibit a highly consistent dendritic geometry in which linear habitat units intersect to create a hierarchical network of connected branches. 2. Ecological and life history traits of species living in streams, such as the potential for overland movement, may interact with this architecture to shape...
Assessing allowable take of migratory birds
M.C. Runge, J.R. Sauer, M.L. Avery, B.F. Blackwell, M.D. Koneff
2009, Journal of Wildlife Management (73) 556-565
Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal...
Species richness and occupancy estimation in communities subject to temporary emigration
M. Kery, J. Andrew Royle, M. Plattner, R.M. Dorazio
2009, Ecology (90) 1279-1290
Species richness is the most common biodiversity metric, although typically some species remain unobserved. Therefore, estimates of species richness and related quantities should account for imperfect detectability. Community dynamics can often be represented as superposition of species-specific phenologies (e. g., in taxa with well-defined flight [insects], activity [rodents], or vegetation...
Hierarchical models for estimating density from DNA mark-recapture studies
B. Gardner, J. Andrew Royle, M.T. Wegan
2009, Ecology (90) 1106-1115
Genetic sampling is increasingly used as a tool by wildlife biologists and managers to estimate abundance and density of species. Typically, DNA is used to identify individuals captured in an array of traps ( e. g., baited hair snares) from which individual encounter histories are derived. Standard methods...
Effect of distance-related heterogeneity on population size estimates from point counts
Murray G. Efford, Deanna K. Dawson
2009, The Auk (126) 100-111
Point counts are used widely to index bird populations. Variation in the proportion of birds counted is a known source of error, and for robust inference it has been advocated that counts be converted to estimates of absolute population size. We used simulation to assess nine methods for...
Conservation of northern bobwhite on private lands in Georgia, USA under uncertainty about landscape-level habitat effects
J.E. Howell, C. T. Moore, M.J. Conroy, R.G. Hamrick, R.J. Cooper, R.E. Thackston, J.P. Carroll
2009, Landscape Ecology (24) 405-418
Large-scale habitat enhancement programs for birds are becoming more widespread, however, most lack monitoring to resolve uncertainties and enhance program impact over time. Georgia?s Bobwhite Quail Initiative (BQI) is a competitive, proposal-based system that provides incentives to landowners to establish habitat for northern bobwhites (Colinus virginianus). Using data...
Analysis of capture–recapture models with individual covariates using data augmentation
J. Andrew Royle
2009, Biometrics (65) 267-274
I consider the analysis of capture–recapture models with individual covariates that influence detection probability. Bayesian analysis of the joint likelihood is carried out using a flexible data augmentation scheme that facilitates analysis by Markov chain Monte Carlo methods, and a simple and straightforward implementation in freely available software. This approach...
Species differences in the sensitivity of avian embryos to methylmercury
G. H. Heinz, D. J. Hoffman, J.D. Klimstra, K.R. Stebbins, S. L. Kondrad, C. A. Erwin
2009, Archives of Environmental Contamination and Toxicology (56) 129-138
We injected doses of methylmercury into the air cells of eggs of 26 species of birds and examined the dose-response curves of embryo survival. For 23 species we had adequate data to calculate the median lethal concentration (LC50). Based on the dose-response curves and LC50s, we ranked species...
A hierarchical model for estimating density in camera-trap studies
J. Andrew Royle, James D. Nichols, K.Ullas Karanth, Arjun M. Gopalaswamy
2009, Journal of Applied Ecology (46) 118-127
Estimating animal density using capture–recapture data from arrays of detection devices such as camera traps has been problematic due to the movement of individuals and heterogeneity in capture probability among them induced by differential exposure to trapping.We develop a spatial capture–recapture model for estimating density from camera-trapping data which contains...
The influence of use-related, environmental, and managerial factors on soil loss from recreational trails
Nathaniel D. Olive, Jeffrey L. Marion
2009, Journal of Environmental Management (90) 1483-1493
Recreational uses of unsurfaced trails inevitably result in their degradation, with the type and extent of resource impact influenced by factors such as soil texture, topography, climate, trail design and maintenance, and type and amount of use. Of particular concern, the loss of soil through erosion is generally considered...
Monitoring multiple species: Estimating state variables and exploring the efficacy of a monitoring program
S.D. Mattfeldt, L.L. Bailey, E.H.C. Grant
2009, Biological Conservation (142) 720-737
Monitoring programs have the potential to identify population declines and differentiate among the possible cause(s) of these declines. Recent criticisms regarding the design of monitoring programs have highlighted a failure to clearly state objectives and to address detectability and spatial sampling issues. Here, we incorporate these criticisms to...
Multistate models for estimation of survival and reproduction in the Grey-headed Albatross (Thalassarche chrysostoma)
Sarah J. Converse, William L. Kendall, Paul F. Doherty Jr., Peter G. Ryan
2009, The Auk (126) 77-88
Reliable information on demography is necessary for conservation of albatrosses, the most threatened family of pelagic birds. Albatross survival has been estimated using mark-recapture data and the Cormack-Jolly-Seber (CJS) model. However, albatross exhibit skipped breeding, violating assumptions of the CJS model. Multistate modeling integrating unobservable states is a promising tool...
Sampling design considerations for demographic studies: a case of colonial seabirds
William L. Kendall, Sarah J. Converse, Paul F. Doherty Jr., Maura B. Naughton, Angela Anders, James E. Hines, Elizabeth Flint
2009, Ecological Applications (19) 55-68
For the purposes of making many informed conservation decisions, the main goal for data collection is to assess population status and allow prediction of the consequences of candidate management actions. Reducing the bias and variance of estimates of population parameters reduces uncertainty in population status and projections, thereby reducing the...
