Dr. Chris Williams Research Lab

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Thank you for visiting my website. It is through a combination of theoretical and applied ecology that I, and my research team, attempt to better understand the ecology of organisms, the functionality of systems, and apply the results to future management efforts. Our work occurs in upland, coastal, and riparian ecosystems. Click on any of the links above to learn more about our efforts. Brant

Dr. Christopher K. Williams, Associate Professor of Wildlife Ecology
I use both theoretical and applied ecology to understand wildlife populations and their interaction with habitat. This interest also allows me to investigate microscale interactions of animal behavior and nutrition on population ecology as well as macroscale interactions of population dynamics across ranges and functionality of landscape systems.

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Contact

253 Townsend Hall

Department of Entomology and Wildlife Ecology

University of Delaware

Newark, Delaware 19716

Phone: 302-831-4592

Email: ckwillia@udel.edu

Education

Ph.D. Wildlife Ecology, Minor in Natural Resource Policy, University of Wisconsin, 2001. Dissertation title: “Advantages of group size in northern bobwhite coveys.” Advisor: R. Scott Lutz.
M.S. Wildlife Ecology, University of Wisconsin, 1996. Thesis title: “Winter ecology of the northern bobwhite in Kansas cropland and rangeland ecosystems.” Advisor: Donald H. Rusch.
B.S. Zoology, Miami University, 1994. Research Advisor: Gary W. Barrett.
B.S. Botany, Miami University, 1994.

Professional Experience

Assistant Professor, University of Delaware, Department of Entomology and Wildlife Ecology, 2004 – present. Research and professional service (59%): wildlife populations and wildlife habitat interactions. Teaching (40%): Wildlife Population Dynamics, Wildlife Policy and Administration, Wildlife Conservation and Ecology, Wildlife Habitat Management, Readings in Ecology, and Wildlife Management. Service (1%): department, college, university.
Faculty Affiliate, Quantitative Biology, Depatments of Biological Sciences and Mathematical Sciences, University of Delaware, 2009 - present.
Faculty Affiliate, Center for Managed Ecosystems, University of Delaware, 2008 – present.
Faculty Affiliate, Center for Critical Zone Research, Delaware Biotechnology Institute, University of Delaware, 2008 – present.
Research Associate, University of Wisconsin – Madison, Department of Zoology, 2002 – 2004. Advisor: Tony R. Ives. Research: Investigating individually based and spatially explicit models to address the impact of habitat fragmentation on winter northern bobwhite group movement and cohesiveness.
Lecturer, University of Wisconsin – Madison, Department of Wildlife Ecology, Spring 2004. Taught “Animal Population Dynamics”.
Lecturer, University of Wisconsin – Rock County, Department of Biology, Fall 2003. Taught “Concepts of Biology” and “Conservation of Natural Resources”.
Research Associate, University of Wisconsin – Madison, Department of Zoology, 2001 – 2002. Advisor: Tony R. Ives. Research: Investigated and modeled population variability of four small game species across the core and periphery of their range.
Associate Lecturer, University of Wisconsin – Stevens Point, Department of Wildlife. 2000. Taught “Wildlife Population Dynamics”.
Research and Teaching Assistant, University of Wisconsin – Madison, Department of Wildlife Ecology, 1996 – 2001. Developed and conducted population and behavioral ecology research on birds and mammals in collaboration with the Kansas Department of Wildlife and Parks. Supervised 11 employees and 2 employee initiated research projects. Taught 5 semesters “Wildlife Population Dynamics”.

Professional Service

Associate Editor, The Journal of Wildlife Management 2009-2011
Chair of the Scientific Program Committee, American Ornithological Union Annual Meeting in Philadelphia, PA, 2007-2009.
Instructor, Conservation Leaders for Tomorrow, Wildlife Management Institute, 2009 - present.
Coordinator, Northern Bobwhite Conservation Initiative Mid-Atlantic Planning Workshop, 2009
The Wildlife Society: Donald H. Rusch Memorial Game Bird Scholarship Committee, 2004 – 2005, 2006-2007. 14th Annual Conference of the Wildlife Society moderator of oral session “Birds and communities”, 2007.
Habitat Planning Committee, U.S. Fish and Wildlife Service Atlantic Coast Joint Venture, New England/Mid-Atlantic Bird Conservation Region 30, 2004.
Society memberships: Sigma Xi Scientific Research Society, 1993-2010, The Wildlife Society (National:1995-2010, North Central Chapter: 2005-2010), The Ecological Society of America (1993-1995, 2000-2010, Mid-Atlantic Chapter 2006-2010), American Ornithologists’ Union (2008-2010), North American Colleges and Teachers of Agriculture (2006-2009)

Current Post-doctoral Researchers

Available...
Building a population model for resident Canada geese in the Atlantic Flyway

Current Ph.D. Graduate Students

Solny Adalsteinsson
M.S. Applied Ecology, Expected 2011
B.S. Biology, Clarion University of Pennsylvania, 2006
Predicted effects of sea level rise on waterfowl carrying capacity at coastal impoundments in Delaware

Current M.S. Graduate Students

Gavin Ferris
M.S. Applied Ecology, Expected 2011
B.S. Biology, Clarion University of Pennsylvania, 2006
The effect of forested riparian corridor width on phosphorus retention and invasive plant presence

Sadie Ulman
M.S. Wildlife Ecology, Expected 2011
B.A. Zoology, University of Wisconsin-Madison, 2004
The value of Chickaloon Flats, Kenai National Wildlife Refuge, Alaska, to Shorebird Migration and Staging.

Orrin Jones

Orrin Jones
M.S. Wildlife Ecology, Expected 2012
B.S. Wildlife Ecology, University of New Hampshire, 2009.
Incorporating nocturnal behaviors in an American black duck bioenergetics model estimation of carrying capacity

Jeremiah Heise

Jeremiah Heise
M.S. Wildlife Ecology, Expected 2012
B.S. Wildlife Ecology, University of Wisconsin-Stevens Point, 2008.
The effect of nocturnal behaviors on Atlantic brant daily energy expenditures

Curtis Bennett
M.S. Wildlife Ecology, Expected 2013
B.S. Environmental Science and Policy (Concentration in Wildlife Management and Ecology), University of Maryland, 2009.
A predictive habitat model for river otters in New Jersey estuarine habitats

Past Graduate Students

Kate Guerena
M.S. Wildlife Ecology, Expected 2011
B.S. Biology, New York University 2004
Resident Canada Geese Nesting and Brood Ecology

Amanda Conover
M.S. Wildlife Ecology, Expected 2011
B.S. Environmental Resource Management, Minors Watersheds & Water Resources and Environmental Soil Science, Pennsylvania State University, 2007
Current Employment: Program Coordinator, Ohio Bird Conservation Initiative
Thesis: The impact of non-native plants on bird communities in suburban forest fragments
Related Publications:Conover, A. M., V. D’Amico, and C. K. Williams. Non-native Plant Impacts on Songbird Habitat Occupancy in Suburban Forest Fragments. In Review.

Ken Duren
M.S. Wildlife Ecology, University of Delaware, 2010.
B.S. Wildlife Ecology, University of Wisconsin-Stevens Point, 2008
Current Employment: Ohio Department of Natural Resources
Thesis: A predictive habitat occupancy model of northern bobwhite in the Delmarva Peninsula, USA
Related Publications:
1. Duren, K., C. K. Williams, J. J. Buler, W. Jones. Effects of broadcast caller on estimating density and occupancy of northern bobwhite. In Review.
2. Duren, K., J. J. Buler, C. K. Williams, and W. Jones. A predictive habitat occupancy model for northern bobwhite (Colinus virginianus) within the Delmarva Peninsula. Journal of Wildlife Management 75
3. Duren, K., J. J. Buler, C. K. Williams, and W. Jones. Multi-scale changes in habitat relationship with change in observed occupancy of bobwhite quail in the Delmarva Peninsula, USA.

Zach Ladin
M.S. Wildlife Ecology, University of Delaware, 2010. (2010 College of Agriculture and Natural Resources W.J. Benton Award winner)
B.S. Wildlife Biology and Management, University of Rhode Island, 2003
Current Employment: PhD Wildlife ecology, University of Delaware
Thesis: Bioenergetics and food use of wintering and staging Atlantic brant
Related Publications: Ladin, Z. S., P. M. Castelli, C. K. Williams, and S. R. McWilliams. 2010. Time energy budgets and food use of Atlantic brant across their wintering range. The Journal of Wildlife Management.

Dane Cramer
M.S. Wildlife Ecology, University of Delaware, 2009
B.S. Wildlife and Fisheries Science, Pennsylvania State University, 2006
Current Employment: Ducks Unlimited
Thesis: Estimating habitat carrying capacity form American black ducks wintering in southern New Jersey
Related Publications: Cramer, D. M., C. K. Williams, P. M. Castelli, and T. Yerkes. 2010. Estimating habitat carrying capacity for American black ducks wintering in southern New Jersey. In revision.

Mike Lohr
M.S. Wildlife Ecology, University of Delaware, 2009
B.S. Wildlife and Fisheries Science, Pennsylvania State University, 2005
Current Employment: Project Manager, Pono Pacific Ecosystem Restoration Services, Honolulu, Hawaii.
Thesis: Winter ecology of northern bobwhite in New Jersey
Related Publications: Lohr, M., B. M. Collins, C. K. Williams, and P. M. Castelli. 2010. Life on the edge: northern bobwhite ecology at the northern periphery of their range.The Journal of Wildlife Management.

Bridget M. Collins
M.S. Applied Ecology, University of Delaware, 2008. (2008 College of Agriculture and Natural Resources W.J. Benton Award winner)
B.S. Biology, Environmental Studies, Holy Cross, 2005
Current Employment: National Bobwhite Conservation Initiative Liaison to the USDA Farm Service Agency .
Thesis: Breeding ecology of northern bobwhite in New Jersey
Related Publications:
1. Collins, B.M., C. K. Williams, and P. M. Castelli. 2009. Reproduction and microhabitat selection in a sharply declining Northern Bobwhite (Colinus virginianus) population. The Wilson Journal of Ornithology 121:688–695. PDF
2. Lohr, M., B. M. Collins, C. K. Williams, and P. M. Castelli. 2010. Life on the edge: northern bobwhite ecology at the northern periphery of their range. The Journal of Wildlife Management.
3. Williams, C. K., and B. M. Collins. 2008. Mortality. #649 In S. E. Jorgensen (ed.) Encyclopedia of Ecology. Elsevier Press, Oxford, England.

Undergraduate Researchers

Edwards, Christine. 2010. Atlantic brant: issues and management for airline safety.
Baker, Sarah. 2010. The effect of radiocollars of northern bobwhite survival.
Johnson, Zariel. 2010. The effect of latitude on density dependent and independent effects on population growth. University of Delaware Science Scholar and Howard Hughes Medical Institute (HHMI) Scholar.
Zaccaria, Jamie. 2010. The influence of invasive plant prevalence on catbird occupancy of fragmented forests. University of Delaware Science Scholar.
Hendrickson, Phillip. 2010. The effect of disturbance on black duck habitat use.
Ashley Colavecchio. 2009. Developing an extension program for the Mid-Atlantic Bobwhite Initiative. University of Delaware Extension Scholars.
Pippins, Kelly. 2009. Measuring the competition coefficient between Bewick’s wren and house wren populations. Howard Hughes Medical Institute (HHMI) Scholar.
Johnson, Zariel. 2009. Measuring the competition coefficient between Bewick’s wren and house wren populations. National Science Foundation EPSCoR.
Irvin, Eric-Evan. 2009. A predictive habitat model for grasshopper sparrows in Delaware. University of Delaware Science Scholar.
Zaccaria, J. 2009. The effect of invasive plants on songbird abundance. University of Delaware Science Scholar.
Dilworth, Erin. 2008. The effect of riparian forested corridors on fish biodiversity in suburban and agricultural landscapes. Delaware Water Resources Center Internship.
Hathaway, Ryan. 2008. The effect of riparian forested corridors on bird biodiversity in suburban and agricultural landscapes. University of Delaware Research Foundation Research Experience for Undergraduates.
Morgan, Jessica. 2007. The effects of forested riparian corridor width on invasive plant establishment. Science and Engineering Scholar.
Romero, Oscar. 2007. Effect of forested riparian corridor width within agricultural and suburban dominated ecosystems on salamander populations. McNair Scholar.
Diggins, Corrine. 2006. Effects of forested riparian corridor width on soil chemistry within agricultural and suburban dominated ecosystems. Undergraduate Research.

Updated 7/1/2010

My research interests can touch on many aspects of population ecology. For instance, as a faculty associate with the Quantitative Biology Program at the University of Delaware, I have been able to sponsor 3 undergraduate research efforts investigating theoretical avian population ecology systems. However, my primary research while at the University of Delaware focuses on the population ecology and habitat use of northern bobwhite quail and waterfowl. I will discuss these three primary research projects during my time at the University of Delaware.

I. NORTHERN BOBWHITE ECOLOGY

Predictive Habitat Modeling of Northern Bobwhite
The Northern Bobwhite Conservation Initiative (NBCI) has created a comprehensive habitat management plan that defines explicit habitat enhancement or creation objectives to reverse the population decline. Literature on predicting species presence contains numerous methodological recommendations that reduce bias associated with imperfect detection of individuals, scale of model variables, model selection uncertainty, and spatial autocorrelation. In the last several years my lab and I have conducted a series of research projects to advance predictive habitat occupancy for the Mid-Atlantic States. First, my graduate student Ken Duren (graduated 2010) and I conducted repeat-visit surveys at 360 sites within Delaware during 2008-2009 to sample the presence of bobwhite. Using a mixture of site and landscape scale variables that were biologically relevant, we built a predictive model for the Delmarva Peninsula. This research is in review at Ecological Applications. A similar effort was conducted with the State of New Jersey and is scheduled to be submitted for publication in summer of 2010. The modeling results and distribution maps will be used to guide future habitat management efforts. In addition to the base habitat modeling, 2 additional research projects have spun out of this effort. First, Ken Duren and I tested the efficacy of a broadcast caller for estimating density and occupancy of northern bobwhite. This research is in review at the Journal of Wildlife Management. Second, Ken Duren and I tested if a habitat occupancy model could predict the change in occupancy of Breeding Bird Survey (BBS) routes over time in the Delmarva Peninsula, USA between 1992-2005. Predicted route occupancy was not related to observed route occupancy across sampling periods and we hypothesize a series of biological and methodological considerations for the discrepancy.

Northern Bobwhite Ecology in New Jersey
The northern bobwhite is experiencing precipitous declines in abundance since the 1960’s. Although this has occurred throughout their range, it has been particularly noticeable in the northern periphery of their range. These declines have mainly been attributed to urban/suburban sprawl, “clean” agriculture, and the resulting fragmentation of remaining habitat. Essentially no studies have specifically addressed bobwhite habitat selection and population parameters in the Mid-Atlantic United States. As the most densely populated state in the United States, New Jersey represents one of the most fragmented landscapes within the geographic range of the bobwhite. Therefore, an assessment of the relationships among predation rates, local habitat quality, and landscape characteristics is necessary for bobwhite conservation planning. Two graduate students and I conducted a continuous monitoring of two breeding and two non-breeding seasons to elucidate the factors limiting the abundance of northern bobwhite in this peripheral population. Bridget Collins (graduated in 2008) studied breeding season survival, habitat use, and nest success and Mike Lohr (graduated 2009) studied winter survival and habitat use. Two publications have come from this research in The Wilson Journal of Ornithology (2009) and the Journal of Wildlife Management (2010).

Demographic Sensitivity of Population Change in the Northern Bobwhite
Despite numerous field studies, there have been few attempts to model the population dynamics of bobwhites to determine the contributions of different demographic parameters to the variance of the finite rate of population change (lambda). Working with 3 other coauthors, we conducted a literature review to summarize available estimates of demographic parameters for bobwhite and located 320 estimates of nine demographic parameters in 42 field studies. To identify demographic parameters that might be important for management, we used life-stage simulation analysis (LSA) to examine the sensitivity of lambda to simulated variation in nine demographic parameters for female bobwhite. Unexpectedly for a short-lived bird, winter survival of adults made the greatest contribution to variance in lambda, followed by summer survival, survival of chicks, and the probability of nest success. Bobwhite populations were not sustainable for survival rates reported from most field studies and radio-transmitters may have a negative impact on bobwhite survival. Our simulation results indicate that management practices that improve survival from independence to the following breeding season will have the greatest potential benefit for population recovery. This research was published in 2008 in the Journal of Wildlife Management.

Movement Patterns and Habitat Use of Differing Sized Northern Bobwhite Groups
The group size of social animals and spatial structure of the environment can affect group behavior and movement decisions. Although previous research has investigated the presence of optimal group sizes and other research has investigated movement patterns of animals, rarely have these two components been combined. Two coauthors (Tony Ives and Roger Applegate) and I investigated how optimal and suboptimal group sizes differ in their use of the landscape in relation to their differing needs, using northern bobwhite coveys as an example. Using radio-telemetry research collected in Kansas during the winters between 1997-2000, we examined continuously monitored covey group size, daily movement, habitat use, and survival. We used correlated random walk models and fractal dimension models to determine if group size affected movement characteristics or habitat selection. We analyzed movement characteristics at multiple spatial scales to ask whether coveys of different sizes exhibited different scaling patterns in movement behavior. This research is currently in review with the Journal of Animal Ecology.

The Northern Bobwhite Decline: Scaling Our Management For the 21st Century
In 2003 I initiated a paper that would critically evaluate traditional management of northern bobwhite throughout the 20th century and determine if it was still valuable in the face of massive population declines and advances in the field of wildlife ecology. I co-wrote this article with Fred Guthery from Oklahoma State University, Roger Applegate with the Kansas Department of Wildlife and Parks, and Markus Peterson with Texas A&M University. Even though northern bobwhite have been one of the most broadly researched and intensively managed species in North America, we argued that a disadvantage of this status was that traditional management principles were currently incompatible with the spatial scale necessary to address the nationwide decline in bobwhite abundance. We maintained that halting or reversing this decline would entail 2 principal changes in the scale of management. Primarily we suggested that habitat management needed to switch from historical fine-scale management (promotion of edge habitat, weedy fencelines, disked strips, living hedges, and food plots) to regional management of usable space. Secondly, within these regional management areas, we argued managers should apply harvest management that employs risk-sensitive strategies that conservatively avoid undermining the primary goal. This would entail narrowing the scale of harvest management from statewide to regional levels. Our manuscript was published in 2004 in the Wildlife Society Bulletin.

II. WATERFOWL ECOLOGY

Bioenergetics of Wintering Waterfowl
The availability of food for energy is the primary factor limiting waterfowl populations during winter and migration. As degradation of tidal marsh habitat in the Atlantic flyway has and will most likely continue to occur, quantifying the energetic potential for wintering waterfowl in the region is important to future management. To date, I have mentored 4 graduate students who are researching varying aspects of this need. First Dane Cramer (graduated in 2009) estimated the potential carrying capacity of non-breeding black duck habitat in coastal New Jersey by measuring food resource availability and depletion, habitat use and availability, and energy use through different behavioral states in available habitats. His research is in revision with the Journal of Wildlife Management and we are conducting additional research to investigate the affects of human development on habitat use by wintering black ducks. A second researcher, Zach Ladin (graduated in 2010), built a bioenergetics model for Atlantic brant across their primary wintering range (Rhode Island to Virginia) by quantifying winter time/energy budgets via behavioral observation. This research is being published in the Journal of Wildlife Management. Additionally we determined food preference and energetic potential of foods in different habitat types and time of year using gross evaluation as well as stable isotopic signatures. We are finishing this manuscript and plan to submit it in July, 2010. Finally, I have two current graduate students, Orrin Jones and Jeremiah Heise who are researching black duck and brant nocturnal behaviors. Because previous efforts to quantify behavior for time-energy budgets have focused on diurnal or crepuscular activities, there is potential for bias for species known to be active at night. Additionally we are examining how diurnal disturbances (e.g. hunting) might alter the need for nocturnal behavior to compensate for lack of diurnal feeding time. Therefore, using the latest night vision technology we aim to quantify behaviors across a series of spatially and temporally diverse states to improve carrying capacity estimates for these two species. These four research projects will ultimately be invaluable to the Atlantic Flyway’s knowledge of these species and ability to prescribe habitat management and harvest regulations. Future research is currently in development to extend our bioenergetics modeling to address potential carrying capacities in future sea level rise scenarios and changing habitat availability.

Resident Canada Goose Reproductive Potential and Population Modeling
A need exists to determine the productivity of Atlantic Flyway Resident Population (AFRP) Canada geese in order to better manage their increasing population and evaluate the efficacy of current population control efforts. Leading this effort, my graduate student, Kate Guerena, is studying the nesting ecology of AFRP Canada geese in 2009 and 2010 throughout the state of New Jersey. We are measuring nest and hatch success as well as gosling survival while accounting for accompanying land use, habitat and nest site type, nest phenology, predator activity, and adult behavior during visits. This data will be compared with eight years of historic nesting data from New Jersey, spanning over the last 25 years, for the purpose of developing long-term nesting, brood-rearing, and productivity trends in the AFRP. A new project starting in 2011 will expand this work to development of a more comprehensive population model for AFRP Canada geese, including recruitment, annual survival, and migration.

Winter Fidelity and Survival of Lesser Snow Geese
The Beringia region of the Arctic contains 2 colonies of lesser snow geese breeding on Wrangel Island, Russia and Banks Island, Canada and wintering in North America. The Wrangel Island population is composed of 2 subpopulations from a sympatric breeding colony but separate wintering areas, whereas the Banks Island population shares a sympatric wintering area in California with one of the Wrangel Island subpopulations. The Wrangel Island colony represents the last major snow goose population in Russia and has fluctuated considerably since 1970, whereas the Banks Island population has more than doubled. The reasons for these changes are unclear. Using banding and resighting data, I used multi-state mark-recapture models to evaluate apparent survival rates, resighting rates, winter fidelity, and potential exchange among these populations. The results of my analysis showed similar apparent survival rates between subpopulations of Wrangel Island snow geese and lower apparent survival, but higher emigration, for the Banks Island birds. Transition between wintering areas was low (<3%), with equal movement between northern and southern wintering areas for Wrangel Island birds and little evidence of exchange between the Banks and northern Wrangel Island populations. The results of my analysis suggest that northern and southern Wrangel Island subpopulations should be considered a metapopulation in better understanding and managing Pacific Flyway lesser snow geese. This research paper was published in 2008 in the Journal of Wildlife Management.

III. THEORETICAL POPULATION ECOLOGY

I have always been interested in the dynamics of populations. For example, I conducted a study that determined how density dependent and density independent processes vary across the geographical ranges of three small game species (Williams, C. K., A. R. Ives, and R. D. Applegate. 2003. Population dynamics across geographical ranges: time-series analysis of three small game species. Ecology 84:2654-2667). I found that populations at range peripheries have substantially higher variability than populations towards the centers of ranges due to increased environmental stocasticity and density dependent responses to this variability. Secondly, I also completed a study on the latitudinal patterns of the 10-year population cycles of North American grouse. Theoretically, if population cycles disappear they can collapse either by shortening or lengthening their period length. All previous research (primarily on rodents in Europe) has found that cycles collapse in southern latitudes through a shortening of period. This was hypothesized to occur through an increase in generalist predation and direct density dependence. My research, however, showed that the characteristic North American 10-year cycle collapses via period lengthening. The cause of this relationship appears to be a weakening of delayed density dependent processes (Williams, C. K., A. R. Ives, R. D. Applegate, and J. Ripa. 2004. The collapse of cycles in the dynamics of North American grouse populations. Ecology Letters 7:1135-1142). Third, through a cooperative research project with the Quantitative Biology Program and undergraduate researchers, we recently invetigated measuring the strength of interspecific compeitition between 2 species of wrens. Understanding competition between species is a critical aspect of population ecology and plays an important role in predicting the effects of species interactions. Although competition can be quantified experimentally in artificially controlled environments, these experiments are often expensive and impractical. We presened a method to quantify competition in long-term and spatially-wide wild populations while accounting for nonlinear population growth from readily available time-series data. The theta-logistic two-species population model was fitted to time-series data from the North American Breeding Bird Survey (BBS) to obtain competition coefficients for two species of wren. The competition between house wrens and Bewick’s wrens has been widely observed and well documented as coinciding with a recent increase in the range of the house wren. Approaches were presented for establishing reliable parameter values for the model using BBS data from physiographic Stratum #14, the Highland Rim, and life history information. Competition coefficients for the effect of Bewick’s wren (0.20) and house wren (0.75) populations were obtained. The model predicted stable coexistence of the two species; however, at an extremely low Bewick’s wren population suggesting possible remnant Bewick’s populations can remain in the face of house wren invasion. This methodological foundation will aid biologists in understanding competition between invasive species and native populations.

ACKNOWLEDGEMENTS OF FUNDING AGENCIES

State Agencies

Federal Agencies

Non-Governmental Organizations

Academic

The following is a complete list of publications including peer reviewed research papers, book chapters, and technical bulletins.

Duren, K., J. J. Buler, W. Jones, and C. K. Williams. Multi-scale changes in habitat relationship with change in observed occupancy of bobwhite quail in the Delmarva Peninsula, USA. In Review

Johnson, Z., K. Pippins, J. A. Pelesko, and C. K. Williams. A modified dynamic regression method of interspecific competition: accounting for nonlinear growth in wren time series data. In Review

Duren, K., J. J. Buler, W. Jones, and C. K. Williams. Effects of broadcast caller on estimating density and occupancy of northern bobwhite. In Review.

Williams, C. K., A. R. Ives, and R. D. Applegate. Do movement patterns and habitat use differ between optimal and suboptimal sized groups? Examining the dynamics of northern bobwhite covey behavior. In Revision

Cramer, D. M., P. M. Castelli, T. Yerkes, and C. K. Williams. Estimating habitat carrying capacity for American black ducks wintering in southern New Jersey. In Revision

Williams, C. K., and P. M. Castelli. 2011. A historic perspective of the connectivity between waterfowl research and management. In Sands, J. P., S. J. DeMaso, L. A. Brennan, and M. J. Schnupp (eds). Wildlife science: Connecting research with management. CRC Press: Taylor Francis Group, Boca Raton, Florida, USA.

Duren, K., J. J. Buler, W. Jones, and C. K. Williams. 2011. A predictive habitat occupancy model for northern bobwhite (Colinus virginianus) within the Delmarva Peninsula. Journal of Wildlife Management

Ladin, Z. S., P. M. Castelli, S. R. McWilliams, and C. K. Williams. 2011. Time energy budgets and food use of Atlantic brant across their wintering range. Journal of Wildlife Management

Lohr, M., B. M. Collins, P. M. Castelli, and C. K. Williams. 2011. Life on the edge: northern bobwhite ecology at the northern periphery of their range. Journal of Wildlife Management

Holtcamp, W. N., C. K. Williams, and W. E. Grant. 2010. Do invasive fire ants affect habitat selection within a small mammal community? International Journal of Ecology Article ID 642412:1-7

Long, R., and C. K. Williams. 2010. Northern Bobwhite Conservation Initiative: Bird Conservation Region 30: New England and Mid-Atlantic. The Northern Bobwhite Conservation Initiative: a report on the status of the northern bobwhite and a plan for species recovery. Miscellaneous Publication of the Southeast Association of Fish and Willdife Agencies, South Carolina.

Colavecchio, A., and C. K. Williams. 2010. The northern bobwhite of the Mid-Atlantic: a landowners guide to their ecology and management. University of Delaware Cooperative Extension Bulletin Number 147, Newark, DE. 10pp.

Joppa, L. N., C. K. Williams, S. A. Temple, G. S. Casper. 2010. Environmental factors affecting sampling success of artificial cover objects. Herpetological Conservation and Biology 5:143-148.

Collins, B.M., C. K. Williams, and P. M. Castelli. 2009. Reproduction and microhabitat selection in a sharply declining Northern Bobwhite (Colinus virginianus) population. The Wilson Journal of Ornithology 121:688–695. PDF

Williams, C. K., and B. M. Collins. 2008. Mortality. #649 In S. E. Jorgensen (ed.) Encyclopedia of Ecology. Elsevier Press, Oxford, England. PDF

Sandercock, B. K., B. E. Jensen, C. K. Williams, R. D. Applegate. 2008. Demographic sensitivity of population change in the northern bobwhite: a life-stage simulation analysis. Journal of Wildlife Management 72:970-982. PDF

Marrone, G. M., D. C. Backlund, C. K. Williams, K. Tilmon. 2008. Population estimate of the endangered American burying beetle, Nicrophorus americanus, (Coleoptera:Silphidae) in South Dakota. Coleopterists Bulletin 62:9-15. PDF

Williams, C. K., M. D. Samuel, V. Baranyuk, E. Cooch, and D. Kraege. 2008. Winter fidelity and apparent survival of lesser snow goose populations in the Pacific Flyway. Journal of Wildlife Management 72: 159-167. PDF

Helmus, M. R., T. J. Bland, C. K. Williams, and A. R. Ives. 2007. Phylogenetic measures of biodiversity. American Naturalist 169:E68-E83. PDF

Williams, C. K., A. R. Ives, R. D. Applegate, and J. Ripa. 2004. The collapse of cycles in the dynamics of North American grouse populations. Ecology Letters 7:1135-1142. PDF

Williams, C. K., F. H. Guthery, R. D. Applegate, M. Peterson. 2004. Rescaling northern bobwhite management for the 21st century. Wildlife Society Bulletin 32:861-869. PDF

R. D. Applegate, C. K. Williams, and R. R. Manes. 2004. Assuring the future of prairie grouse: dogmas, demagogues, and getting outside the box. Wildlife Society Bulletin 32:104-111. PDF

Williams, C. K., R. S. Lutz, and R. D. Applegate. 2004. Winter survival and additive harvest in Kansas northern bobwhite coveys. Journal of Wildlife Management 68:94-100. PDF

Williams, C. K., P. J. Rodrick-Williams, R. D. Applegate. 2004. Beliefs and characteristics of Kansas northern bobwhite hunters. Kansas Department of Wildlife and Parks Wildlife Bulletin No. 4.

Williams, C. K., A. R. Ives, and R. D. Applegate. 2003. Population dynamics across geographical ranges: time-series analysis of three small game species. Ecology 84:2654-2667. PDF

Williams, C. K., R. S. Lutz, and R. D. Applegate. 2003. Optimal group size in northern bobwhite coveys. Animal Behaviour 66:377-387.

Applegate, R. D., and C. K. Williams. 2003. Use of roadside survey for gray and fox squirrel populations and harvest. Kansas Department of Wildlife and Parks Small Game Wildlife Bulletin 3.

Van Why, K., B. Flock, R. D. Applegate, and C. K. Williams. 2003. Northern bobwhite (Colinus virginianus) body mass in relation to consumption of red and white grain sorghum. Kansas Department of Wildlife and Parks Small Game Wildlife Bulletin 2.

Williams, C. K., G. Ericsson, and T. Heberlein. 2002. A quantitative summary of attitudes toward wolves and their reintroduction (1972-2000). Wildlife Society Bulletin 30:575-584.

Applegate, R. D., C. K. Williams, and R. S. Lutz. 2002. The effect of flooding on northern bobwhite. Western North American Naturalist 62:227-229.

Van Why, K., C. K. Williams, R. D. Applegate, and B. E. Flock. 2002. A portable aviary for field observations of behavior. Journal of Field Ornithology 73:20-22.

Williams, C. K., W. R. Davidson, R. S. Lutz, and R. D. Applegate. 2000. Health status of northern bobwhite quail (Colinus virginianus) in eastern Kansas. Avian Diseases 44:953-956.

Williams, C. K., R. D. Applegate, R. S. Lutz, and D. H. Rusch. 2000. A comparison of raptor densities and habitat use in Kansas cropland and rangeland ecosystems. Journal of Raptor Research 34:203-209.

Williams, C. K., R. S. Lutz, R. D. Applegate, and D. H. Rusch. 2000. Habitat use and survival of northern bobwhite in Kansas cropland and rangeland ecosystems during the harvest season. Canadian Journal of Zoology 78:1562-1566.

Williams, C. K., K. Van Why, and R. D. Applegate. 2000. Eastern woodrat (Neotoma floridana) consumption of northern bobwhite (Colinus virginianus). American Midland Naturalist 143:239-244.

Applegate, R. D. and C. K. Williams. 1998. Long term small game trends from 30 years of Kansas rural mail carrier surveys. Transactions of the Kansas Academy of Science 101:2-3.

Williams, C. K., R. D. McKown, J. K. Veatch, & R. D. Applegate. 1997. Baylisascaris sp. found in wild northern bobwhite (Colinus virginianus). Journal of Wildlife Diseases 33:158-160.

Peles, J. D., Williams, C. K., G. W. Barrett. 1997. Small mammal population dynamics in strip-cropped vs. monoculture agroecosystems. Journal of Sustainable Agriculture 9:51-60.

Peles, J. D., Williams, C. K., G. W. Barrett. 1995. Ecological energetics of golden mice: the importance of food quality. American Midland Naturalist 133:373-376.

Williams, C. K., V. Witmer, M. Casey, G. W. Barrett. 1994. The effects of strip-cropping on small mammal population dynamics. The Ohio Journal of Science 94:94-98.

Since arriving at the University of Delaware in Fall 2004, I have taught 6 different classes (Wildlife Conservation and Ecology ENWC201, Wildlife Policy and Administration ENWC413/613, Wildlife Population Dynamics ENWC/BISC435/635, Wildlife Habitat Management ENWC 416/616, Wildlife Management ENWC325, and Readings in Ecology ENWC 667). The first three courses are now my primary and consistent course offerings. Wildlife Population Dynamics, Wildlife Policy and Administration, Wildlife Habitat Management, and Readings in Ecology are new courses I designed to expand the Department's course list. Throughout each of the courses that I teach, I work very hard to construct engaging and interactive lectures and create problem-solving exercises to enhance student learning. Promoting student learning, however, requires much more. Courses which contain a heavy quantitative component, such as Wildlife Population Dynamics can be quite challenging for students. To help them rise to the challenge and be successful in the course, it is critical that I actively work with the students one-on-one by making myself available to them. These interactions help to raise their confidence with the material increasing their learning in class and their overall excitement for the subject. Another challenge that students face within the discipline is effective scientific writing. In all my courses, I have designed a series of in-depth writing assignments requiring the students to explore controversial subjects, conduct research, and/or explore population models. To facilitate this process, the students complete these assignments in steps to ensure their successful progress. I believe my efforts to improve student learning through quantitative reasoning and effective writing, while fostering a excitement for wildlife ecology have been successful, as seen in my strong student teaching evaluations, as well as peer evaluations. I have received numerous comments noting my strong commitment to education, my ability to engage students and efforts in designing course materials that assist the learning process. I would like to expand on the topics, techniques, and philosophies for each of the 3 primary classes that I am teaching.

ENWC 201 - Wildlife Conservation and Ecology (Fall)

This freshman level majors course and multilevel nonmajors course is an introduction to biological diversity, ecology, and the issues, problems, and solutions associated with the conservation of wildlife. Humans are only one of the many species in the global ecosystem; however, they have a great impact on the species around them. This course discusses the basic principles of wildlife ecology with focus on the ecological and sociological importance of wildlife and their habitats. We evaluate and discuss the importance of wildlife to our past, present and future with emphasis on wildlife conservation issues such as habitat loss, endangered species, pollution, urbanization, and invasive species. When students complete this course I expect them to 1) understand the basic concepts of ecology in relation to wildlife conservation, 2) know the major groups of wildlife and their general requirements and behaviors, 3) understand the role of humans in wildlife ecology and conservation, 4) know the names of and noted relevant features of species of special relevance to conservation, and 5) know the history, causes and examples of major problems in wildlife conservation, and types, feasibility, and implications of proposed solutions. This is a special and fun course to teach. For majors this is their first introduction to the major and relevant ideas that they will carry throughout their time at the University of Delaware. For nonmajors, this course is often their only exposure to conservation issues. In either case, the students tend to be highly interested and motivated. During the Fall of 2008, the class was only for 35 entering majors which allowed me to take the class into the field on numerous occasions and teach them some fundamental ideas of wildlife observation and measurement. In the Fall of 2009, the course was opened also to nonmajors and the class size grew to 129. Although this disallowed an opportunity to have field days, I still broke the class into smaller groups to discuss case studies of wildlife conservation issues. In either case, the students responded that they enjoyed having an interactive component to the class and it made the experience that more enjoyable. Overall, it has been fun to develop the intellectual curiosity, confidence, and engagement of these students that will lead to lifelong learning and consideration of conservation issues.

ENWC/BISC 435/635 - Wildlife Population Dynamics (Spring)

This senior/graduate level class which is crosslisted between Entomology & Wildlife Ecology and Biological Sciences is an introduction to population ecology, including exponential growth, logistic growth, predator-prey dynamics, competition, metapopulations, harvest dynamics, individual behavior’s affect on population processes, disease modeling, and population and survival estimation techniques. Because this class focuses heavily on theoretical models, I employ 4 techniques to increase student learning and excitement for the subject material. First, I incorporate many research-based examples from peer-reviewed literature to illustrate abstract theories. Second, I often pause during a lecture to allow the students to work through a problem on their own or in groups. This ensures that the students completely understand the equation and have worked through the problem and arrived at the correct outcome. Third, we have multiple in-class discussions of related research articles. This gives the students the opportunity to observe the field application of a theoretical model. Finally, I strongly believe students should also be engaged with the material outside of class. This encourages independent understanding of the principles presented during class. To promote this understanding, I assign in-depth modeling assignments where students explore population ecology models. These assignments are designed to thoroughly assess the students’ basic knowledge of the material, as well as their critical thinking skills. Since these exercises are in-depth and challenging, all students have two opportunities to complete an assignment. After the assignments are initially submitted, I return them to the students with follow up questions which provide hints to how they could improve answers that were not meeting the goals of the assignment. Once they receive these comments, the students have another week to revise their answers to receive additional points. These modeling assignments also are designed to foster the students’ ability to communicate accurately in writing and to synthesize research information and think critically to solve real-world problems in wildlife population ecology; learning goals that have been identified by the Department. In addition to these learning goals, these multiple teaching and assessment techniques used throughout the course provide my students with opportunities to explore topics and integrate ideas learned throughout their education to develop a coherent understanding of population ecology.

Click to expand general lecture schedule for Wildlife Population Dynamics

Lecture 1 – Introductions, review of syllabus, Introduction to population ecology, Model basics and exponential Growth snow geese
Lecture 2 – Practice with Excel in Computer Lab
Lecture 3 – Exponential growth basics
Lecture 4 – Exponential growth, stochasticity, Exponential growth & Logistic growth
Lecture 5 – Logistic Growth - Introduction
Lecture 6 – Logistic Growth – Adding variability
Lecture 7 – Logistic Growth – Adding Nonlinearity
Lecture 8 – Harvesting populations
Lecture 9 – Age structured population growth – Life table composition 1
Lecture 10 – Age structured population growth - Life table composition 2
Lecture 11 – Age structured population growth – Using matrix algebra to predict future populations
Lecture 12 – Age structured population – Elasticity analysis, life stage simulation analysis
Lecture 13 – Competition: theoretical underpinnings
Lecture 14 – Competition: modeling populations, examining state space graphs
Lecture 15 – Predation: modeling populations, examining state space graphs
Lecture 16 – Finish Predation and introduction to the dynamics of population cycles
Lecture 17 – Modeling population cycles through autoregressive formulation
Lecture 18 – Modeling Metapopulations 1
Lecture 19 – Modeling Metapopulations 2
Lecture 20 – Disease models 1
Lecture 21 – Disease models 2
Lecture 22 – Sampling Populations: Census methodology, Line Transects, Point Counts
Lecture 23 – Sampling Populations: Lincoln-Peterson and multiple variance estimators
Lecture 24 – Sampling Populations: Schnabel and Jolly Seber estimation

ENWC 467 - Wildlife Policy and Administration (Fall)

This undergraduate/graduate level course is an introduction to policy issues that relate to wildlife management and natural resources. The class is broken into three sections. First, students are introduced to the policy process including understanding constituent involvement, economic considerations, and legal frameworks. Second, students learn about the history of attitudes and laws toward natural resources in the United States from 1600-1900. Our views toward the public trust are extremely unique and I feel it is important my students understand the foundation upon which modern attitudes and laws toward natural resources are grounded. Third, students learn about the roles, interests, organization, and legal responsibilities on non-governmental organizations, state wildlife agencies, the National Park Service, the United States Fish and Wildlife Service, the United States Forest Service, and the United States Department of Agriculture. Scattered through all these three sections, students gain an understanding of current laws and are therefore responsible for debating and exploring current hot topics through written assignments and in-class discussions. Upon course completion, I expect my students should understand and be able to apply the basic principles of natural resource policy formation and implementation. They also should be knowledgeable with federal treaties, statutes, and regulations related to wildlife in the United States. These include those designed for addressing problem wildlife and those designed to conserve species through restrictions on take, habitat protection, maintaining biodiversity, and managing both species and their habitats. Students also gain proficiency in reading, library research, and writing review papers. Because wildlife and fisheries management in the 21st century has as much to do with politics, environmental policy, and law as ecology principles, this course is designed to prepare students in a fundamental way to succeed as wildlife professionals.

Click to expand general lecture schedule for Wildlife Policy and Administration

Introduction to Policy Roosevelt and Muir
Lecture 1 – Course introduction
Lecture 2 – The Policy Process 1: Constituents
Lecture 3 – The Policy Process 2: Constituents
Lecture 4 – The Policy Process 3: Constituents/ Economics
Lecture 5 – The Policy Process 4: Economics in Natural Resource Policy
Lecture 6 –The Policy Process 5: Economics/ Legal Framework in Natural Resource Policy
Lecture 7 – The Policy Process 6: Legal Framework
American Natural Resource History
Lecture 8 – Early History of Wildlife Policy
Lecture 9 – Early History of Wildlife Policy
Lecture 10 – Early History of Wildlife Policy
Lecture 11 – Early History of Wildlife Policy; the public trust
Lecture 12 – Early History of Wildlife Policy; the public trust
Lecture 13 – Early History of Wildlife Policy; the public trust
Department of the Interior
Lecture 14 – Park Service
Lecture 15 – Park Service
Lecture 16 – USFWS Part 1 – Intro and Refuge System
Lecture 17 – USFWS Part 2 - Migratory Bird Policies
Lecture 18 – USFWS Part 3 - Migratory Bird Policies
Lecture 19 – USFWS Part 4 - Migratory Bird Policies
Lecture 20 – USFWS Part 5 - Endangered Species Act
Lecture 21 – USFWS Part 6 - Endangered Species Act
Lecture 22 – USFWS catch up
Lecture 23 – USFWS catch up
Lecture 24 – USFWS ESA
Lecture 25 – USFWS -Wolves in Yellowstone Movie
Lecture 26 – USFWS – wolf wrap up, BLM, and BOR
Department of Agriculture
Lecture 27 – Forest Service
Lecture 28 – Forest Service
Lecture 30 – Forest Service and NRCS
Lecture 31 – NRCS and CRP Programs
Lecture 32 – USDA – exotic species
Other Agencies and Issues
Lecture 33 – Introduction to Non-governmental organizations (NGO)
Lecture 34 - NGO #2. Guest Lecture: Ducks Unlimited
Lecture 34 – Guest Lecture - State Agency Issues, DNREC
Lecture 35 – Global Issues and Mexico/US Border

PAST COURSES TAUGHT AT UNIVERSITY OF DELAWARE

ENWC 416/616 - Wildlife Habitat Management (Fall 2006, Fall 2007). Within this senior/grad level course, my goals are to 1) acquaint students with basic principles and methods of habitat manipulation to benefit various types of wildlife, 2) ensure students can describe and apply techniques to manipulate vegetation to enhance habitat for selected wildlife, and 3) acquaint students with habitat requirements for forest, grassland, agricultural, prairie, and wetland wildlife that are often the focus of habitat management programs.

ENWC 867 - Readings in Ecology (Spring 2006). Weekly readings and discussions of recent research papers or important books in ecology, evolution, and related topics from organismal biology. Class material will vary between semesters; therefore, class may be repeated for credit.

ENWC 325 - Wildlife Management (Fall 2005).

Thank you for your interest in joining my research team!

Generally, I only bring graduate students on that are a correct fit for a specifically funded project. That being said, I strongly encourage potential students to suggest topics that are of extreme interest to them and for them to propose additional projects that can occur in tandem to the funded project. While I will have funds to support these individuals on a combination of research and teaching assistantships, I encourage all students to apply for fellowships and grants (e.g. a NSF graduate fellowship) to further support their work. Although a fair amount of this field research will occur in states other than Delaware, I will make every effort to provide opportunities for undergraduates to be part of our research team. In my experience, the most successful graduate students are those who are enthusiastic, hardworking, and committed. I believe it is important that my students show a history of academic excellence and strong GRE scores. I am also especially interested in working with those who are driven by curiosity and enjoy trying to solve ecological questions. Often such students have had the opportunity to be involved in research projects as undergraduates and achieve publication in peer reviewed publications from that research. If this sounds like you, feel free to contact me.

GENERAL PHILOSOPHIES AND EXPECTATIONS OF MY STUDENTS

Undergraduates
There are several ways that serious, enthusiastic students can get involved in my lab and gain valuable research experience. These include volunteer opportunities, paid assistantships, and research for course credit. I will give priority to those who think they're headed for graduate school and/or a professional field in ecology or wildlife sciences. Students who are Science and Engineering Scholars or those working toward a senior thesis will be given priority (see the University of Delaware’s Undergraduate Research Program). If this sounds like you, please contact me and tell me about the kinds of things you're interested in.

Graduate students
As someone contemplating graduate school, you have a lot to consider in choosing an advisor, a lab, and a university. Given this, I understand your need to find out as much as possible about me and the University of Delaware before applying. Below you will find information about my philosophy of mentoring students, my expectations of you as a graduate student, and websites you can access for further information. I believe that I have three goals as a graduate mentor. First, it is my responsibility to get you well versed in the fundamental principles of ecology and wildlife sciences, especially those paradigms that are most relevant to your professional goals and interests. Second, my role is to advise you in primary research, helping you develop a solid proposal to test a well-founded idea, and then giving you advice on how to maximize your chance of making a novel contribution to science. Lastly, it is my goal to help you develop the skills, connections, and opportunities that will ensure a successful postgraduate career. Here are a few things I focus on to achieve these goals … Independent thinking – I want my students to develop and pursue their own questions with vigor. Often in wildlife ecology research, projects are handed down from funding agencies. However, I expect my students to find complimentary research questions that can be asked in conjunction with the basic research goals. Also I encourage potential students to work on projects that complement, but are divergent from my own interests. By do this, I believe we all can expand our interests, knowledge, and experiences.
Collaboration – I want students to contribute to the broader intellectual environment of my lab, and I encourage them to participate with other labs and other students in scholarly activities.
Creativity – Bill Shipley, wrote in Cause and Correlation in Biology (2000), “The popular view of scientific discoveries as being linear causal chains from idea to solution is profoundly wrong; a better image would be a tangled web with many dead ends and broken strands.” I encourage students to track down clues wherever they take you, be they traditional methods of science, or more unconventional ones.
Breadth – While one’s own research may be highly focused, I want students to always keep the ‘bigger-picture’ in mind. To help, I support a graduate education that spans a variety of organisms and ecosystems, and numerous theoretical, experimental, observational, and applied approaches in ecology.
Communication – It wildlife ecology, it is critical that research findings are disseminated to the scientific community and the general public. I expect my students to distribute their work at scientific meetings, publish in scholarly journals, and encourage them to write for more popular media. Additionally I expect my students to search out at least one semester of teaching assistant experience, as I believe such experiences are critical to improving communication skills. Written and oral communication is sometimes daunting, however I will make every effort to help students find this a fun and exciting step in the research process.

Some helpful links University of Delaware
University home page (general information about the university)
Department of Entomology and Wildlife Ecology (about the department & graduate program)

Advice on choosing a graduate program
Questions To Ask When Thinking About Pursuing a Ph.D.
Suggestions on how to choose a major professor or graduate program - Dr. Gary Grossman, University of Georgia

This page lists many journals used by wildlife biologists, zoologists, and ecologists. This page is meant to be a reference guide for publication in these journals. For each journal, I have listed links to their home pages (which often includes their instructions for publication), and the Institute of Scientific Information 's impact rating found within these journals. Information gathered from the Institute of Scientific Information is being used here for educational purposes only and cannot be used or duplicated for any unlawful purposes.

JOURNAL	ISI Impact Rating 1997	ISI Impact Rating 1999	ISI Impact Rating 2001	ISI Impact Rating 2003	ISI Impact Rating 2005
Acta Biotheoretica	0.267	0.345	0.533	0.553	0.892
Acta Theriologica				0.629	0.520
American Midland Naturalist	0.485	0.500	0.494	0.701	0.768
American Naturalist	2.903	3.928	4.317	4.059	4.464
Animal Behaviour	1.897	2.148	2.483	2.557	2.669
Animal Conservation				1.481	1.385
Annals of Applied Biology	0.494	0.631	0.529	0.675	1.060
Annals of the New York Academy of Sciences	0.903	0.964	1.593	1.892	1.971
Annual Review of Ecology, Evolution, and Systematics	3.900	5.689	6.238	6.182	10.014
Applied Animal Behaviour Science	0.920	0.815	1.274	1.222	1.441
Arctic	0.500	0.725	0.733	0.518	0.857
Arctic Antarctic and Alpine Research		1.438	1.214	0.954	1.045
Auk	1.074	1.490	1.379	1.597	1.838
Avian Diseases	0.848	0.984	1.167	0.975	0.961
Behaviour	1.090	1.269	1.000	1.306	0.994
Behavioral Ecology	2.023	2.869	2.424	2.473	2.943
Behavioral Ecology and Sociobiology	2.327	2.324	2.353	2.649	2.232
Biodiversity and Conservation					1.401
Biological Conservation	1.108	1.579	1.689	2.056	2.581
Biometrics	0.938	1.335	1.081	1.324	1.602
BioScience				3.266	4.708
California Fish and Game	0.157	0.167	0.080	0.120	0.333
Canadian Field-Naturalist	0.225	0.294	0.345	0.329	0.191
Canadian Journal of Zoology	0.975	1.015	1.168	1.115	1.175
Condor	1.000	1.222	1.104	1.225	1.337
Conservation Biology	1.832	3.240	2.783	3.279	4.110
Copeia				0.748	0.974
Ecography	1.228	1.209	2.078	1.676	2.703
Ecological Applications	2.800	2.784	3.335	2.852	3.804
Ecological Modeling				1.561	1.700
Ecological Monographs	5.300	4.447	5.551	4.793	4.855
Ecological Restoration				0.916	0.993
Ecology	3.139	3.573	3.704	3.701	4.506
Ecology and Society formally Conservation Ecology					2.667
Ecology Letters		1.158	1.928	4.211	5.151
Ethology				1.584	1.621
Evolution	2.715	3.726	3.740	3.833	4.155
Functional Ecology	1.818	1.861	2.144	2.351	3.149
Game and Wildlife Science formally Gibier Faune Sauvage
Herpetologica				0.946	0.922
Ibis	1.311	0.941	1.136	1.139	1.184
International Journal of Galliformes Conservation
Journal of Animal Ecology	2.801	2.994	3.312	2.843	3.399
Journal of Applied Ecology	1.335	1.715	2.937	3.205	4.594
Journal of Avian Biology	1.590	1.532	1.353	1.472	1.752
Journal of Ecology	2.837	2.510	2.291	2.833	4.277
Journal of Ethology				0.725	1.621
Journal of Experimental Biology				2.271	2.712
Journal of Field Ornithology	0.353	0.525	0.602	0.652	0.600
Journal of Fish and Wildlife Management
Journal of Herpetology				0.587	0.817
Journal of International Wildlife Law and Policy
Journal of Mammalogy	0.991	1.008	1.735	1.207	1.265
Journal of Ornithology				0.675	0.850
Journal of Raptor Research	0.353	0.527	0.324	0.414	0.333
Journal of Wildlife Diseases	0.600	0.801	0.841	0.793	0.928
Journal of Wildlife Management	0.986	1.346	1.593	1.479	1.462
Journal of Zoology	0.852	0.958	1.093	1.175	1.220
Landscape Ecology	1.310	1.396	1.863	1.080	2.173
Molecular Ecology	3.086	3.442	2.478	3.870	4.301
Nature	27.368	29.491	27.955	30.979	29.273
Northeastern Naturalist				0.225	1.489
Oecologia	1.854	2.159	2.474	3.128	3.032
Ohio Journal of Science	0.167	0.057	0.229	0.061	0.150
Oikos	1.860	2.566	2.499	2.142	3.309
Physiology and Behavior				2.027	2.183
Population Ecology				0.967	1.424
Prairie Naturalist
Restoration Ecology				0.842	1.380
Royal Society of London Series B					3.510
Science	24.676	24.595	23.329	29.162	30.927
Southeastern Naturalist				0.121	0.333
Southwestern Naturalist	0.173	0.211	0.238	0.209	0.300
Theoretical Population Biology					2.007
Transactions of the Kansas Academy of Science
Transactions of the Wisconsin Academy of Science, Arts, and Letters
Trends in Ecology & Evolution	6.678	7.621	10.508	12.449	14.864
Waterbirds		0.000	0.466	0.337	0.504
Western Birds
Western North American Naturalist Formally Great Basin Naturalist	0.163	0.562	0.312	0.460	0.266
Wetlands
Wildlife Biology			0.603	0.547	0.724
Wildlife Research	0.802	0.691	0.921	0.993	0.795
Wildlife Monographs	2.000	4.444	5.250	1.600	5.286
Wildlife Society Bulletin	0.733	0.712	0.617	1.098	0.944
Wilson Bulletin	0.430	0.553	0.487	0.268	0.274

What is the ISI Journal Citation Report Impact Factor?

The ISI Impact Factor indicates how often articles in a certain journal are cited within the two years following the publication date. For example, the ISI Impact Factor for Ecology in 1996 is calculated as the sum of all 2006 citations of articles published in Ecology in 2004 and 2005 divided by the total sum of all articles publiched in Ecology in those two years.
Robert Peet, editor of Ecology and Ecological Monographs, provided a valuable word of caution about the relativity of ISI Impact Factors between fields:
"Readers should note that the ISI impact factor is based on citations of articles written in the most recent 2 years only. This strongly biases the impact factor toward those fields that cite only the most recent articles, and in which rapid publication is most critical. Half-life statistics make up for this a bit, but the fact is that there is no statistic provided by ISI that is appropriate for assessing the importance or significance of journals in fields like organismal biology, ecology, forestry, historical geology, physical geography, etc. It is very scary that some countries base funding for fields on the impact factors of the journals that publish in those fields. Just the fact that it takes longer to publish in ecology and forestry than in molecular biology and physics, and that the papers are fewer but longer, puts the fields at a disadvantage. "TREE gets a high impact in part because the articles are newsy and consequently somewhat ephemeral; they are not nearly as rich in content as Ecology, American Naturalist and similar primary Journals. Science and Nature get high impact factors because they publish mostly fields where only the most recent articles are important, and speed is of the essence."

Dr. Christopher K. Williams ▪ Department of Entomology & Wildlife Ecology ▪ University of Delaware ▪ 253 Townsend Hall ▪ Newark, DE 19716
Telephone: (302) 831-4592 ▪ Fax: (302) 831-8889 ▪ ckwillia@udel.edu