Julien Martin, Ph.D.
Julien Martin is a Supervisory Biologist based at the Eastern Ecological Science Center.
Julien Martin is a Supervisory Biologist at the US Geological Survey's Eastern Ecological Science Center. He is the capability team manager of the Quantitative Methods and Decision Science team. He obtained a Ph.D. in the department of Wildlife Ecology and Conservation at the University of Florida. He is a courtesy faculty in the Department of Wildlife Ecology and Conservation at the University of Florida. His expertise includes: ecological modeling, population dynamics and the application of decision theory to natural resource management.
Professional Experience
01/2022-Present: Supervisory Biologist at the US Geological Survey (USGS) at the Eastern Ecological Science Center. Laurel, MD.
09/2014-01/2022: Research Wildlife Biologist at the US Geological Survey (USGS) Wetland Aquatic Research Center. Gainesville, FL.
07/2009-09/2014: Research Scientist at the Fish and Wildlife Research Institute/Florida Fish and Wildlife Conservation Commission (FWC), St. Petersburg, FL.
10/2019-present: Courtesy Associate Professor in the Department of Wildlife Ecology and Conservation, University of Florida, Gainesville.
01/2010-10/2019: Courtesy Assistant Professor in the Department of Wildlife Ecology and Conservation, University of Florida, Gainesville.
07/2007-06/2009: Postdoctoral Research Associate at Patuxent Wildlife Research Center (USGS, Laurel, MD).
09/2001-05/2007: Graduate Research Assistant at the Florida Cooperative Fish and Wildlife Research Unit, USGS/Department of Wildlife Ecology and Conservation at the University of Florida, Gainesville, FL, 40 hours/week. Supervisor:
09/2000-09/2001: Graduate Research Assistant at the Centre d’Etudes Biologique de Chize (CEBC), Centre National pour la Recherche Scientifique (CNRS) and French Polar Institute (IPEV), Chize, France.
10/1998-03/2000: Wildlife Field Biologist and environmental advisor in French Subantarctic islands, Centre National pour la Recherche Scientifique (CNRS) and French Polar Institute (IPEV), Kerguelen and Crozet islands, French Southern and Antarctic Lands.
1998: Field biologist for the Irish Fisheries Board, Dublin, Ireland.
Education and Certifications
Ph.D., Wildlife Ecology and Conservation, University of Florida
Science and Products
Application of threshold concepts to ecological management problems: Occupancy of Golden Eagles in Denali National Park, Alaska
Thresholds for conservation and management: structured decision making as a conceptual framework
The effect of changes in habitat conditions on the movement of juvenile Snail Kites Rostrhamus sociabilis
Accounting for non-independent detection when estimating abundance of organisms with a Bayesian approach
Multispecies modeling for adaptive management of horseshoe crabs and red knots in the Delaware Bay
An adaptive-management framework for optimal control of hiking near golden eagle nests in Denali National Park
Optimal control of native predators
Simultaneous modeling of habitat suitability, occupancy, and relative abundance: African elephants in Zimbabwe
Perturbation analysis for patch occupancy dynamics
Dynamic multistate site occupancy models to evaluate hypotheses relevant to conservation of Golden Eagles in Denali National Park, Alaska
Exploring the temporal effects of seasonal water availability on the snail kite of Florida: Part III
Science and Products
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Application of threshold concepts to ecological management problems: Occupancy of Golden Eagles in Denali National Park, Alaska
In this chapter, we demonstrate the application of the various classes of thresholds, detailed in earlier chapters and elsewhere, via an actual but simplified natural resource management case study. We intend our example to provide the reader with the ability to recognize and apply the theoretical concepts of utility, ecological and decision thresholds to management problems through a formalized dAuthorsMitchell J. Eaton, Julien Martin, James D. Nichols, Carol McIntyre, Maggie C. McCluskie, Joel A. Schmutz, Bruce L. Lubow, Michael C. RungeThresholds for conservation and management: structured decision making as a conceptual framework
A conceptual framework is provided for considering the threshold concept in natural resource management and conservation. We define three kinds of thresholds relevant to management and conservation. Ecological thresholds are values of system state variables at which small changes bring about substantial or specified changes in system dynamics. They are frequently incorporated into ecological modelAuthorsJames D. Nichols, Mitchell J. Eaton, Julien MartinThe effect of changes in habitat conditions on the movement of juvenile Snail Kites Rostrhamus sociabilis
The degradation of habitats due to human activities is a major topic of interest for the conservation and management of wild populations. There is growing evidence that the Florida Everglades ecosystem continues to suffer from habitat degradation. After a period of recovery in the 1990s, the Snail Kite Rostrhamus sociabilis population suffered a substantial decline in 2001 and has not recovered siAuthorsAndrea C. Bowling, Julien Martin, Wiley M. KitchensAccounting for non-independent detection when estimating abundance of organisms with a Bayesian approach
Summary1. Binomial mixture models use repeated count data to estimate abundance. They are becoming increasingly popular because they provide a simple and cost‐effective way to account for imperfect detection. However, these models assume that individuals are detected independently of each other. This assumption may often be violated in the field. For instance, manatees (Trichechus manatus latirostAuthorsJulien Martin, J. Andrew Royle, Darryl I. MacKenzie, Holly H. Edwards, Marc Kery, Beth GardnerMultispecies modeling for adaptive management of horseshoe crabs and red knots in the Delaware Bay
Adaptive management requires that predictive models be explicit and transparent to improve decisions by comparing management actions, directing further research and monitoring, and facilitating learning. The rufa subspecies of red knots (Calidris canutus rufa), which has recently exhibited steep population declines, relies on horseshoe crab (Limulus polyphemus) eggs as their primary food source duAuthorsConor P. McGowan, David R. Smith, J. A. Sweka, Julien Martin, James D. Nichols, R. Wong, J. E. Lyons, L. J. Niles, K. Kalasz, J. Brust, M. Klopfer, B. SpearAn adaptive-management framework for optimal control of hiking near golden eagle nests in Denali National Park
Unintended effects of recreational activities in protected areas are of growing concern. We used an adaptive-management framework to develop guidelines for optimally managing hiking activities to maintain desired levels of territory occupancy and reproductive success of Golden Eagles (Aquila chrysaetos) in Denali National Park (Alaska, U.S.A.). The management decision was to restrict human accessAuthorsJulien Martin, Paul L. Fackler, James D. Nichols, Michael C. Runge, Carol L. McIntyre, Bruce L. Lubow, Maggie C. McCluskie, Joel A. SchmutzOptimal control of native predators
We apply decision theory in a structured decision-making framework to evaluate how control of raccoons (Procyon lotor), a native predator, can promote the conservation of a declining population of American Oystercatchers (Haematopus palliatus) on the Outer Banks of North Carolina. Our management objective was to maintain Oystercatcher productivity above a level deemed necessary for population recoAuthorsJulien Martin, Allan F. O'Connell, William L. Kendall, Michael C. Runge, Theodore R. Simons, Arielle H. Waldstein, Shiloh A. Schulte, Sarah J. Converse, Graham W. Smith, Timothy Pinion, Michael Rikard, Elise F. ZipkinSimultaneous modeling of habitat suitability, occupancy, and relative abundance: African elephants in Zimbabwe
The recent development of statistical models such as dynamic site occupancy models provides the opportunity to address fairly complex management and conservation problems with relatively simple models. However, surprisingly few empirical studies have simultaneously modeled habitat suitability and occupancy status of organisms over large landscapes for management purposes. Joint modeling of these cAuthorsJulien Martin, Simon Chamaille-Jammes, James D. Nichols, Herve Fritz, James E. Hines, Christopher J. Fonnesbeck, Darryl I. MacKenzie, Larissa L. BaileyPerturbation analysis for patch occupancy dynamics
Perturbation analysis is a powerful tool to study population and community dynamics. This article describes expressions for sensitivity metrics reflecting changes in equilibrium occupancy resulting from small changes in the vital rates of patch occupancy dynamics (i.e., probabilities of local patch colonization and extinction). We illustrate our approach with a case study of occupancy dynamics ofAuthorsJulien Martin, James D. Nichols, Carol L. McIntyre, Goncalo Ferraz, James E. HinesDynamic multistate site occupancy models to evaluate hypotheses relevant to conservation of Golden Eagles in Denali National Park, Alaska
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. We applied multistate site occupancy moAuthorsJulien Martin, Carol L. McIntyre, James E. Hines, James D. Nichols, Joel A. Schmutz, Margaret C. MacCluskieExploring the temporal effects of seasonal water availability on the snail kite of Florida: Part III
The Florida snail kite (Rostrhamus sociabilis) is an endangered raptor that occurs as an isolated population, currently of about 2,000 birds, in the wetlands of southern and central Florida, USA. Its exclusive prey species, the apple snail (Pomacea paludosa) is strongly influenced by seasonal changes in water abundance. Droughts during the snail kite breeding season have a direct negative effect oAuthorsWolf M. Mooij, Julien Martin, Wiley M. Kitchens, Donald L. DeAngelis - Software
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