H Brian Underwood, Ph.D.

I collaborate with DOI partners, USGS and academic colleagues on mission-critical problems or emerging issues. I conduct research primarily through graduate student mentoring and advising. Secondarily, I provide technical assistance to partners that often lead to interesting research questions and products.


Professional Experience

  • Research Wildlife Biologist, 1990-present.


  • BS (1982); Wildlife Resources Management, West Virginia University, Morgantown.
  • MS (1986); Wildlife Ecology, State University of New York College of Environmental Science and Forestry, Syracuse.
  • PhD (1990); Wildlife Ecology, State University of New York College of Environmental Science and Forestry, Syracuse.

Current Research Emphasis

  • applied population biology, ecology and demography
  • natural resource conservation and management
  • systems modeling and simulation
  • trophic dynamics of plant-herbivore, prey-predator systems
  • numerical ecology and applied statistics

Honors, Awards and Recognition

  • Patuxent Scientific Achievement Award, 3/00
  • Service Appreciation, Bureau of Land Management, 5/99
  • Regional Director’s Award (Northeast Region) for Natural Resource Research, National Park Service, 5/98
  •  Merit Award for Scientific Contributions, Fire Island National Seashore, 2/98

Professional Society Affiliations

  • The Wildlife Society, Northeast Section, New York Chapter


  • Cooperative Agreements Training, 1991
  • Population Dynamics Workshop, SREL, 1991
  • The Role and Responsibilities of Those Using Animals in Research and Teaching, 1994
  • The Internet as a Faculty Tool, Syracuse University, 1995
  • Making a Syllabus Page for the WWW, Syracuse University, 1995
  • ArcView II Short‑course, SUNY- ESF Continuing Education, 1995
  • Capture and Chemical Anesthesia of Wildlife, 1996
  • AAA Driver Improvement Program, 2005
  • USGS Field Employee Safety Orientation, 2005


 DATES: June 2010                                         To: Present

Impacts of Super-Storm Sandy and Deer Browsing on the Establishment, Development and Persistence of Maritime Vegetation  Principal Technical Advisor and Co-PI; Funding source: National Park Service, Fire Island National Seashore.

 This project seeks to understand the impact of Hurricane Sandy and deer on the establishment, development and growth of maritime vegetation.  I advise two permanent staff biologists (and their technicians) and help them identify and implement research and monitoring activities to understand the implications of natural and anthropogenic disturbance to the conservation status of imperiled plant species and communities. (Percentage Time: 70, Percentage R&D: 90)

Predicting the effects of both natural and anthropogenic disturbance on the persistence of species and communities is an important thrust in conservation biology.  Barrier island vegetation is well-adapted to natural disturbances that disrupt sandy substrates.  Beach nourishment, artificial dune construction, sediment transport and erosion and the effects of the built environment also significantly impact natural vegetation, and much remains to be studied.  Additionally, chronic herbivory that disrupts natural regeneration processes of barrier island plants and communities may make them more vulnerable to extinction.  My primary research includes: (1) evaluating the effects of deer browsing on vegetation establishment, growth and development in key natural zones, (2) characterizing remaining maritime forest fragments, (3) analyzing movements of deer in and around hurricane impact zones, and (4) constructing probabilistic models that reflect key disturbance mechanisms, rates of change and past and future states.

Using Modern Statistical Approaches for Estimating Wildlife Population Abundance. ─ PI; Funding Sources: National Park Service, Fish & Wildlife Service, US Geology Survey.

 This project is an ongoing effort to promulgate methods that explicitly account for missed detections in the estimation of abundance of biological populations in parks and refuges. (Percentage Time: 25, Percentage R&D: 85)

 Most counts of wildlife are biased low because the probability of detection is rarely perfect.  Probability of detection is affected by many factors, though vegetation obstruction caused by seasonal phenology is most important at this latitude.  I have employed distance sampling since its modern inception in the early 1980s, and have been using other methods (e.g., occupancy estimation) that explicitly account for missed detections during wildlife counts.  I look for opportunities to test new ideas and new applications of these methods in parks and refuges.  I am currently exploring density surface modeling as an alternative to stratified, distance sampling density estimation, the use of spatially-explicit capture-recapture methods of non-invasive sampling, and quantifying the effects of visual conspicuity (a psychophysical determinant of search performance) and visual clutter on detection probability.  With a former student, I am developing simplified, encounter rate models that predict abundance to within reasonable precision targets.

            Graduate Student Mentoring and Research ─ Major Advisor, Committee Member; Primary Funding Source: Department of Environmental & Forest Biology of SUNY ESF. 

(Percentage Time: 5, Percentage R&D: 95)

Part of my obligation to the host academic institution is to advise and mentor young professionals.  Recruiting talented and qualified graduate students allows me to meet that obligation and to explore new and emerging research topics outside of targeted DOI RFPs.  I generally mentor 1-4 graduate students at a time, depending on the quality of the candidate pool, availability of space and funding.  Students in my lab conduct independent research projects that are often, but not always, related to mine.  I sometimes support students on DOI funded projects, but more often, my students are supported by departmental funds and small grants.  I help students develop research proposals, write grants to obtain project funding, collect and analyze data, make professional presentations, write their thesis or dissertation and publish their research products.

 Name and Title of Supervisor:  Linda Weir, Branch Chief of Migratory Birds & Ecosystem Science, USGS Patuxent Wildlife Research Center


DATES:  Autumn 1996                                  To: Spring 2010

Research Wildlife Biologist, USGS Patuxent Wildlife Research Center, Syracuse Field Station, College of Environmental Science & Forestry, Syracuse, New York.  As a Field Station scientist, I engaged in a broad spectrum of wildlife and related research, including inventory, monitoring, impact analysis, risk assessment, population ecology and management, natural resources policy and planning.

DATES:  Spring 1993                                     To: Autumn 1996

             Research Wildlife Biologist, National Biological Service (NBS), College of Environmental Science & Forestry, Syracuse, New York.  I served as Leader, Cooperative Park Studies Unit, later to be transferred to the former NBS, Division of Cooperative Research.

DATES From:  Spring 1990                           To:  Spring 1993

            Regional Wildlife Biologist, National Park Service, Boston, Massachusetts.  I was responsible for organizing and coordinating region-wide studies of white-tailed deer ecology and management on National Park Service units, and served as contract officer on all other wildlife-related research projects. 



Using biophysical models to predict species responses to climate change.

  • Background ─ Moose populations in the northern continental US have been steadily declining over the past 40 years.  More recent declines have been documented in New England.  Changing thermal regimes resulting from climate warming have been implicated in a cascade of direct and indirect impacts on moose populations.  In addition to the direct effects of heat stress, increased parasitism by winter ticks (Dermacentor albipictus) and long-term shifts in northern forest composition are anticipated to impact moose numbers region-wide.  In New York’s Adirondack State Park (ASP), a re-colonizing moose population has increased to about 800 individuals in 25 years.  Over the same period, meteorological records indicate increases in summer and winter temperatures, lower snowfall amounts and over-winter snow pack, earlier ice-out dates and later ice-in dates on lakes, earlier leaf emergence and bloom dates of plants, and other indicators of regional climate warming.  Elucidating critical linkages between changing thermal environments, habitat utilization and behavioral thermoregulation is critical for determining the effects of climate on the future distribution of moose. 
  • Role ─ I designed a research project to determine the effect of the thermal environment on heat balance in moose through the calculation of operative temperature.  With a graduate student, we (1) modeled elevational differences in ambient temperature across the ASP during periods of heat stress for moose, (2) used hemispherical photography and micro-meteorology to estimate solar radiation reaching the forest floor, (3) modified several existing heat balance formulations for wild and domestic mammals to predict operative temperature under 3 canopy types, and (4), incorporated thermal constraints into a conventional habitat suitability model for moose.
  • Results ─ Validated against a long-term dataset of moose observations, our model better classified moose into high, medium or low habitat suitability than a similar model that did not account explicitly for the thermal environment. 
  • Impact ─ This is the first field study to integrate modeling, geospatial analysis, hemispherical photography and micro-meteorology to explore the impacts of climate change on a large mammal like moose.  It represents the first study to explicitly incorporate thermal constraints into a habitat suitability model for a large herbivore, and verified that the most thermally hostile period for moose occurs in early spring before snowmelt and not during the height of summer.  This project has been recognized for its originality, complexity and excellence.

Stochastic population dynamics of unmanaged white-tailed deer populations.

  • Background ─ In many parts of the eastern U.S., white-tailed deer populations have existed for decades at densities high enough to cause concern for human health and safety and ecological impacts.  For white-tailed deer, the effects of density on harvest and yield have been well-studied.  Much less is known about the effects of environmental stochasticity on deer population fluctuations.  Embarking on deer density reduction with only an understanding of density dependent responses could quickly lead to mistakes in management and lost credibility.   
  • Role ─ Over a decade ago, I encouraged parks to estimate deer density and its uncertainty using the methods I refined and recommended.  Using data from 16 cooperating parks, I (with a graduate student) estimated parameters of a population model from datasets varying in length from 7 - 13 years.  The model integrates the effects of density dependence and environmental stochasticity on population fluctuation.  We conducted Monte Carlo-style simulations to explore parameter bias owing to structural elements of the model and data quality.
  • Results ─ We demonstrate that variability in population size over time is positively related to weather-induced, environmental stochasticity and that more variable populations are characterized by lower carrying capacities.  Finally, we characterize thresholds of data quality (ratios of process to sampling variance) required to estimate parameters of the stochastic population model with reasonable precision.
  • Impact ─ Because we show that the expression of density dependence is context specific, the use of generalized sustained yield relationships could lead to management failures, and that agency policy for deer reductions in parks and refuges should also account for environmental stochasticity.


Accounting for missed detections in wildlife population abundance surveys.

  • Background ─ Counts of most organisms are difficult to interpret because abundance is often confounded by differential detection.  Accounting for missed detections is a major procedural improvement in abundance/occupancy estimation in recent years.  While interest in the application of distance sampling is high, technical expertise is still limited in most natural resource agency settings. 
  • Role ─ Since the early 1990s, I have designed, planned and executed various distance sampling protocols in a variety of contexts using state-of-the-art software and creative field methods.  These efforts have increased the quality and veracity of data used for the management of species’ populations.  I developed a 2-3 day workshop that includes a field exercise where participants collect and analyze their own data, adapted to different species and circumstances.
  • Results ─ With students and colleagues, I have successfully applied the method along straight-line transects, along curving transects by using GPS technology and planar geometry, for one-sided and two-sided transects, for statewide abundance estimation for deer, and to the understanding the long-term population dynamics of un-hunted deer populations.  Since 2000, nearly 200 natural resource professional have attended my workshops.
  • Impact ─ My distance sampling protocols for estimating deer density and abundance are being used in over a dozen national parks, several national wildlife refuges and state parks.  In addition, a distance sampling protocol I helped to develop is being applied across the extant distribution of the endangered, Karner blue butterfly.  Recently with colleagues, we deployed a point-sampling procedure using call-response surveys and distance sampling to estimate the statewide abundance of coyotes (Canis latrans) in New York.  Hansen, S. J. K., J. Frair, H. B. Underwood, and J. P. Gibbs. Pairing call-response surveys and distance sampling for a mammalian carnivore. Submitted December, 2013.

Use of fertility control for managing wild herbivores.

  • Background ─ Fertility control is often viewed as a non-lethal alternative to population management for wild herbivores.  Indeed in some circumstances, population control has been efficacious; yet in others, control remains elusive due to logistical factors affecting vaccine delivery.   
  • Role ─ I explored the promises and pitfalls of fertility control on wild horses at Assateague Island National Seashore and then on white-tailed deer at Fire Island National Seashore and elsewhere.  I modified harvest management theory, designed field studies and constructed simulation models to examine the efficacy of fertility control in settings where conventional means of population management are limited.
  • Results ─ I constructed the first stochastic model of wild horse population dynamics with a fertility control option.  I developed additional probabilistic models for deer at Fire Island National Seashore and Morristown National Historical Park.  From a study designed with colleagues in a suburban setting, I used regional matrix population models to define specific criteria for which fertility control could be contemplated, and the role of dispersal in determining success or failure in adjacent areas with different population targets.
  • Impact ─ Though the application of fertility control to wild populations of remains quite limited, my research contributions are among the first to detail the conditions under which it could succeed as a population management tool.


My primary leadership role as a scientist has been in helping resource managers understand the ecological implications of overabundant herbivore populations in parks and refuges.  I assist them in estimating deer abundance, in characterizing impacts to important natural and cultural resources, understanding the scope of issues caused by deer overabundance, and casting the problems in a scientific framework and lead to resolution.  Early in my career, I convened The Science of Overabundance (TSO) symposium with colleagues at the Smithsonian Institute’s Center for Conservation Research to review the state of the science regarding deer overabundance on public lands.  An edited volume comprised of select papers from the symposium was a significant contribution to our understanding at the time.  Published by the Smithsonian Institution Press, the book received national attention and was reviewed favorably by several prestigious journals.  TSO  was nominated for the Wildlife Society’s 1998 Wildlife Publication Award, and helped managers frame overabundance in ecological terms.  The TSOand subsequent research products have invited much dialog about mammal management on public trust lands, and influenced several revisions of natural resource management policies of state and federal agencies.  Since then, I continue to explore aspects of overabundance and details of the irruption process, which takes longer to complete than a career in the sciences.  I have served on 2 BRD RGE panels and 1 GD RGE panel.