Eric L. Walters

Assistant Professor

Department of Biological Sciences, Old Dominion University

 

 

 

Research

My research program encompasses facets of community ecology, theoretical ecology, conservation biology, and evolution. I use a variety of scientific approaches to integrate applied, theoretical, and basic research. Methods of investigation include field experiments, long-term demographic studies, and mathematical modeling in order to understand how species interact with each other and their environment; all within a larger conservation biology framework. For ease of presentation, I have tried to pigeon-hole my research into the following broad categories. Please realize, however, that there is much overlap among the categories that I provide below.


Evolution of Mating Systems

Ecological Constraints, Reproductive Skew, and the Evolution of Cooperative Breeding in the Acorn Woodpecker

Collaborators: Walter D. Koenig (Cornell University); Joey Haydock (Gonzaga University) ONGOING RESEARCH

The mating system of the acorn woodpecker (Melanerpes formicivorus) is among the most complex of any vertebrate, with groups consisting of a breeding core of up to seven cobreeding males and three joint-nesting females mating together (cooperative polygynandry) in combination with a variable number of nonbreeding helpers that are offspring from prior years and that have delayed dispersal to remain on their natal territory. Males compete to mate and females lay their eggs communally in the same nest. Cobreeders of the same sex are almost always close relatives, either siblings or parents and offspring. The project tests experimentally the role of roosting / nesting cavities and of storage facilities in which groups store acorns as ecological constraints leading to delayed dispersal by offspring and cooperative polygamy by same-sex coalitions of relatives. The project also involves a study of reproductive skew among cobreeding males. Previous work revealed that joint-nesting groups of females, unlike males, share parentage equally. Through experiments, behavioral observations, and genetic analyses; we are attempting to determine the factors that influence reproductive sharing in acorn woodpecker societies. A primary goal of this study is to understand the fitness consequences of cooperative breeding and to integrate findings into the larger questions of the evolution and ecology of group living in highly social species like acorn woodpeckers and humans. 

Prinz, A.C.B., V.K. Taank, V. Voegeli, and E.L. Walters. 2016. A novel nest-monitoring camera system using a Raspberry Pi micro-computer. Journal of Field Ornithology 87(4):427-435.

Koenig, W.D. and E.L. Walters. 2016. Provisioning patterns in the cooperatively-breeding acorn granarywoodpecker: can feeding behaviour serve as a signal? Animal Behaviour 119:125-134.

McMahon, D., I.S. Pearse, W.D. Koenig, and E.L. Walters. 2015. Tree community shifts and acorn woodpecker population increases over three decades in a California oak woodland. Canadian Journal of Forest Research 45(8):1113-1120.

Koenig, W.D. and E.L. Walters. 2015. Temporal variability and cooperative breeding: testing the bet-hedging hypothesis in the acorn woodpecker. Proceedings of the Royal Society B: Biological Sciences 282: 20151742.

Koenig, W.D., E.L. Walters, J. M.H. Knops, and W. J. Carmen. 2015. Acorns and acorn woodpeckers: ups and downs in a long-term relationship. Pp. 23-33. In [Standiford, Richard B.; Purcell, Kathryn L., tech. cords]. Proceedings of the seventh California oak symposium: managing oak woodlands in a dynamic world. Gen. Tech. Rep. PSW-GTR-251. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. 579 p.

Koenig, W.D., E.L. Walters, I.S. Pearse, and J.M.H. Knops. 2014. Serotiny in California oaks. Madroño 61:151-158.

Koenig, W.D. and E.L. Walters. 2014. What we don't know, and what needs to be known, about the cooperatively breeding Acorn Woodpecker Melanerpes formicivorus. Acta Ornithologica 49(2):221-232.

Rusk, C.L., E.L. Walters, and W.D. Koenig. 2013. Cooperative breeding and long-distance dispersal: a test using vagrant records. PLoS ONE 8(3):e58624. doi:10.1371/journal.pone.0058624 Koenig, W.D. and E.L. Walters. 2012. An experimental study of chick provisioning in the cooperatively breeding acorn woodpecker. Ethology 118:566-574.

Koenig, W.D. and E.L. Walters. 2012. Brooding, provisioning, and compensatory care in the cooperatively breeding acorn woodpecker. Behavioral Ecology 23:181-190.

Koenig, W.D., E.L. Walters, and J. Haydock. 2011. Fitness consequences of within-brood dominance in the cooperatively breeding acorn woodpecker. Behavioral Ecology and Sociobiology 65:2229-2238.

*Koenig, W.D. and E.L. Walters. 2011. Age-related provisioning behaviour in the cooperatively breeding acorn woodpecker: testing the skills and the pay-to-stay hypotheses. Animal Behaviour 82:437-444. *This article is featured by the executive editor in the September issue.

Koenig, W.D., E.L. Walters, and J. Haydock. 2011. Variable helper effects, ecological conditions, and the evolution of cooperative breeding in the acorn woodpecker. American Naturalist 178:145-158.

Koenig, W.D., E.L. Walters, and J. Haydock. 2009. Helpers and egg size in the cooperatively breeding acorn woodpecker: testing the concealed helper effects hypothesis. Behavioral Ecology & Sociobiology 63:1659-1665.

Koenig, W.D., J.P. McEntee, and E.L. Walters. 2008. Acorn harvesting by acorn woodpeckers: annual variation and comparison with genetic estimates. Evolutionary Ecology Research 10:811-822.
2006-2007 Winter Field Crew 2007 Spring Field Crew
2007-2008 Winter Field Crew 2008 Spring Field Crew
2008 Summer Field Crew 2008-2009 Winter Field Crew
2009 Spring Field Crew 2009-2010 Winter Field Crew
2010 Spring Field Crew 2010 Spring/Summer Field Crew
2010-2011 Winter Field Crew 2011 Spring Field Crew
2011 Summer Field Crew 2011-2012 Winter Field Crew
2012 Spring Field Crew 2012-2013 Winter Field Crew

We hire field assistants year round. If interested, see our employment page.


Seed Dispersal

Avian Seed Dispersal Ecology in the Wet Forests of the Dominican Republic

My graduate student, Spencer Schubert, is studying seed dispersal (the movement of seeds away from the parent plant) within tropical forests of the Dominican Republic. Several fruiting species produce a crop multiple times per year and Spencer is trying to determine why such a strategy has evolved. He is also examining the network of frugivore mutualists and their role in determining the biodiversity of wet forests in the region.

 

 

The role of generalist avian frugivores in determining the distribution of the mistletoe

My graduate student, Nick Flanders, is examining the role of frugivorous birds in the dispersal and distribution of oak mistletoe (Phoradendron leucarpum). Through this project, Nick aims to further develop his understanding of plant ecology, interactions between birds and plants in the southeastern US, and the use of occupancy models to estimate bird distributions.

 

The role of hackberry (Celtis occidentalis) as a keystone resource for fall migrant songbirds

My graduate student, Chance Hines, is studying the role of hackberry (Celtis occidentalis) as a keystone resource within migrant songbird stopover habitat. Through a mutualism with hackberry gall psyllids, hackberry trees indirectly create species-rich patches of fruiting plants that are used by migrant songbirds during stopovers in the auturmn.

 

 


Community Ecology

Markov Properties of Species Assemblages

Collaborators: Matthew Spencer (University of Liverpool) ONGOING RESEARCH

The succession of species assemblages has been modeled as a Markovian process by investigators for over 40 years. We are challenging some of the assumptions and generalizations that have been used over the past four decades. Inherent problems are illustrated through our analysis of various datasets and a meta-analysis of published studies.

Walters, E.L. Submitted. Unintended consequences of competitor removal: Markov chain community development models reveal hidden relationships. Journal of Animal Ecology.

 

Estimating species interactions in a woodpecker tree-hole community at the individual, population, and community levels

Collaborator: Frances C. James (Florida State University)

Longleaf Pine ForestSpecies assemblages are often dependent upon a discrete resource (e.g. dung patches, pitcher plants, and carcasses). Often, these types of discrete resources are ephemeral or temporary in nature. Through both empirical (field experiments in the Apalachicola National Forest) and theoretical (modeling) work, I examine the nature in which these dynamic resources determine the species assemblage associated with them.

The system that I work with is the community associated with Red-cockaded Woodpecker cavities. The cavities are excavated by Red-cockaded Woodpeckers and then used by a variety of mammals, birds, reptiles, amphibians, and invertebrates. Most of the occupants (birds and mammals) use the cavities for reproduction and, thus, the cavity is integral to their life history. I have examined the properties of the cavities such as the rate at which they are recruited and lost from the system and the rate at which they change in size over time. Species interactions that occur among members of the community were determined empirically through a variety of experiments that manipulated both cavities and species within the community. Some of the publications that have emerged (and will emerge) from this work are outlined below.Red-cockaded Woodpecker Cavity Web

Walters, E.L. and F.C. James. Short-term dynamics among species using a discrete resource, cavities in living pines. Submitted / In Revision.

Walters, E.L.. Using Markov chain community development models within a conservation framework. Submitted / In Revision.

Walters, E.L. and F.C. James. 2010. Quantifying purported competition with individual- and population-level metrics. Conservation Biology 24(6):1569-1577.

Resource Ratio TheoryTilman Model

Collaborators: Thomas E. Miller (Florida State University); Jean H. Burns (Washington University); Hannah L. Buckley (Lincoln University); Jamie M. Kneitel (Cal State, Sacramento); Nicolas Mouquet (University of Montpelier); Pablo Munguia (Smithsonian Environmental Research Center); Paul M. Richards (NOAA)

A model of species interactions based on their use of shared resources was proposed in 1972 by Robert MacArthur and later expanded by David Tilman. This "resource-ratio theory" has been used to make a number of testable predictions about competition and community patterns. We reviewed 1,333 papers that cite Tilman’s original two publications to determine whether predictions of the resource-ratio theory have been adequately tested and to summarize their general conclusions. Most of the citations do not directly test the theory: only 26 studies provide well-designed tests of one or more predictions, resulting in 42 individual tests of predictions. Most of these tests were conducted in the laboratory or experimental microcosms and used primary producers in freshwater systems. You can read more about our findings in the following publications.

Miller, T.E., J.H. Burns, P. Munguia, E.L. Walters, J.M. Kneitel, P.M. Richards, N. Mouquet, and H.L. Buckley. 2005. A critical review of twenty years' use of the Resource Ratio Theory. American Naturalist  165(4):439-448.

Miller, T.E., J.H. Burns, P. Munguia, E.L. Walters, J.M. Kneitel, P.M. Richards, N. Mouquet, and H.L. Buckley. 2007. Evaluating support for the resource-ratio hypothesis: a response to Wilson et al. American Naturalist 169(5):707-708.

Phytotelmata

Container habitats provide ideal opportunities for the study of community ecology. Each container provides the habitat for an entire community of organisms. We studied organisms associated with two types of phyotelmata: pitcher plants and woodpecker tree holes of northern Florida.

Pitcher Plants

Pitcher Plant2004. Buckley, H., J. Burns, J. Kneitel, E.L. Walters, P. Munguia, and T.E. Miller. Small-scale patterns in community structure of Sarracenia purpurea inquilines. Community Ecology 5(2):181-188.

Water-filled Woodpecker Tree Holes

Walters, E.L. and J.M. Kneitel. 2004. Use of water-filled red-cockaded woodpecker cavities by other organisms. Pp. 492-497 in: Costa, R. and S.J. Daniels, eds. Red-cockaded woodpecker: road to recovery. Hancock House Publishers, Blaine, Washington.


CONSERVATION BIOLOGY

Urban Fragmentation and its Effect on North America's Atlantic Migratory Flyway

ONGOING RESEARCH

Understanding the role of urban fragmentation on wildlife movement patterns is critical to long-term conservation of species using such areas. One of North America's most important migration routes, the Atlantic Flyway, follows a path directly over an urban area of 1.6 million people. Hampton Roads, the 2nd largest port in North America, provides important stopover habitat to millions of birds each year. Fragmented patches of protected habitat are critically important to many migratory species. Our work examines the role that these habitat patches play for both resident and migratory species within the urban matrix. The project also involves a significant public outreach component whereby members of the public get to experience bird banding up close and get a better understanding of the suite of species that rely on these remnants of habitat within a large major city.

 

 

Using NPOL/TOGA/NEXRAD Radar To Determine Habitat Use and Flight Paths of Migratory Birds Along the Atlantic Flyway

Collaborators: Jeff Buler (University of Delaware), Barry Truitt (The Nature Conservancy), Deanna Dawson (USGS), Walt Petersen (NASA)

ONGOING RESEARCH

In conjunction with NASA's ground validation dual polarimetric radar (NPOL), we are studying migrant flight behavior along Virginia's Eastern Shore. The radar will be based at the NSF LTER site at Oyster and will be used by our research team to study migrant movement behavior in the spring and fall along Virginia's Delmarva Peninsula. More info. Press release.

 

Bird Window Kills

Collaborators: Annie Sabo, Natasha Hagemeyer, Ally Lahey

ONGOING RESEARCH

Window KillsSince 2013 we have been studying bird window kills. Up to a billion birds die per year in North America as a result of striking windows. We are conducting research at the Virginia Zoo and the Old Dominion University campus. We are also part of a national effort to look at nationwide trends in bird mortalities because of windows.

Sabo, A.M., Hagemeyer, N.D.G., Lahey, A.S., and E.L. Walters. 2016. Local avian density influences risk of mortality from window strikes. PeerJ 4:e2170; DOI 10.7717/peerj.2170.

 

Red-cockaded Woodpecker Habitat Structure

Collaborators: Frances C. James (Florida State University); Charles A. Hess (US Forest Service)

Pine ModelSince early 1997 I have been heavily involved in Red-cockaded Woodpecker (an endangered species) management activities. As part of our research group at Florida State University, we have been examining the effect of fire, forestry activity, competitors, and the U.S. Fish & Wildlife Service's translocation program on the largest remaining population (approximately 600 groups in the Apalachicola National Forest) of Red-cockaded Woodpeckers in the world. The following chapter examines forest structure and contrasts two populations of red-cockaded woodpeckers with respect to the size distribution of pine trees. We are currently examining other demographic differences between the two populations with 15 years of demographic data.

James, F.C., Richards, P., Walters, E.L., Schrader, M., Hess, C.A. and K. McCluney. 2004. Sustainable forestry for the red-cockaded woodpecker’s ecosystem. Pp. 60-69 in: Costa, R. and S.J. Daniels, eds. Red-cockaded woodpecker: road to recovery. Hancock House Publishers, Blaine, Washington.

Invasive Species / New Records

Introduced in 1869, gypsy moths have invaded over 1 million square kilometers of forest in North America. We examine the effects of this massive disturbance event on North American woodpecker species.

Heller, E.L., K.C.R. Kerr, Dahlan, N.F., Dove, C.J., and E.L. Walters. 2016. Overcoming challenges to morphological and molecular identification of Empidonax flycatchers: a case study from the first occurrence record of Dusky Flycatcher in Virginia. Journal of Field Ornithology. DOI 10.1111/jofo.12132

Koenig, W.D., E.L. Walters, and A.M. Liebhold. 2011. Effects of gypsy moth outbreaks on North American woodpeckers. Condor: an international journal of avian biology. Condor 113:352-361.

Red-headed Woodpecker Population Declines

Red-headed woodpeckers have undergone large population declines over much of their range. We examine various potential causes and make recommendations on how to reverse the population decline.

Koenig, W.D. and E.L. Walters. 2017. Testing alternative hypotheses for the cause of population declines: the case of the Red-headed Woodpecker. Condor 119:143-150

Habitat Conservation PlansGolden-cheeked Warbler / Species Management Plans

I was part of an NCEAS (National Center for Ecological Synthesis and Analysis) working group examining the science behind the United States Fish & Wildlife Service's Habitat Conservation Plan. Under Section 10 of the Endangered Species Act, Habitat Conservation Plans must be developed when endangered species are found on private land and a risk of "take" is apparent. We summarized the science behind all of the HCPs that had been conducted up until the date we initiated our analysis. The fruit of our labor was published in Conservation Biology in 2001. Prior to this work, I had coauthored species management plants for the red and blue listed forest and grassland birds of British Columbia.

Desert TortoiseHarding, E.K., E.E. Crone, B.D. Elderd, J.M. Hoekstra, A.J. McKerrow, J.D. Perrine, J. Regetz, L.J. Rissler, A.G. Stanley, E.L. Walters*, and NCEAS HCP Working Group. 2001. The scientific foundations of habitat conservation plans: a quantitative assessment. Conservation Biology 15:488-500 (*order of authors alphabetical after lead author)

Fraser, D.F. and E. Walters. 1993. Preliminary species management plan for Brewer’s Sparrow, subspecies breweri, in British Columbia. British Columbia Ministry of Environment, Lands and Parks Report, Victoria. 12pp.

Fraser, D.F., E.L. Walters, and C. Siddle. 1990. Species management plans for the red and blue listed forest and grassland birds of British Columbia. Contract report to the Wildlife Branch, Ministry of Environment, Victoria, B.C.

Transportation-related Wildlife MortalityLake Jackson Ecopassage

Collaborator: Matthew J. Aresco (Nokuse Plantation)

I have been interested in the effect of roads on population demographics for a number of years. As a former member of the Lake Jackson Ecopassage Advisory Group, we were charged with making recommendations on how to stem the unprecedented wildlife mortality associated with US Highway 27 at Lake Jackson, Florida. This 1-km stretch of highway has the highest turtle road mortality ever recorded worldwide. For more information, see the Lake Jackson Ecopassage web site that has been set up. A similar situation is occurring with the endangered Alabama Red-bellied Turtle. We are currently working on some demographic models that show the population is currently headed to extinction, given yearly mortality attributed to roads.

Purple Martin Population Declines

In the early 1990s, I was part of a study that documented that fewer than 30 Purple Martins were left in British Columbia. We erected hundreds of nest boxes in a last-ditch conservation effort to prevent the species from being extirpated from the province. It worked - recent population estimates are currently in the hundreds.

Fraser, D.F., C. Siddle, D. Copley and E. Walters. 1997. Status of the Purple Martin in British Columbia. Wildlife Working Report No. WR-89. 38 p.

Copley, D.R. and E.L. Walters. 1991. Purple Martin nest box programme summary - 1990. Victoria Naturalist 47:4-9.Purple Martin

Siddle, C., E.L. Walters, and D.R. Copley. 1991. Status report of the Purple Martin, Progne subis, in British Columbia. Contract report to the Wildlife Branch, Ministry of Environment, Victoria, B.C.

Walters, E.L., D.R. Copley and S.J. Statton. 1990. Purple Martin report finds fewer than 30 birds left in B.C. Victoria Naturalist 47:1-4.

Utility Structure - Wildlife Interactions

Collaborator: Richard E. Harness (EDM International, Inc.)

Catastrophic failure from woodpecker nestingSince 1997 I have been working with utility organizations and companies throughout the United States and Canada to examine factors influencing wildlife - utility structure interactions. The focus of my work has been on determining the extent to which woodpeckers damage utility structures and evaluating potential preventative and mitigative measures. My research has found that most woodpeckers are using wood utility structures for either nesting or foraging activities. Ways of preventing such damage depend upon the species involved, geographic location, nearby habitat structure, integrity of the pole, chemical treatment of the pole, previous mitigation measures, and many other factors. Each case of damage must be examined on an individual basis - there are no general trends that allow companies to predict utility structure susceptibility to damage. A field visit (supplemented with historical information) is usually necessary so that recommendations can be made to prevent, reduce, or repair woodpecker damage.

Harness, R.E. and E.L. Walters. 2005. Knock on wood: woodpeckers and utility pole damage. IEEE Industry Applications Magazine 11(2):68-73.Pileated Woodpecker damage

2004. Harness, R.E. and E.L. Walters. Woodpeckers and utility pole damage. Rural Electric Power Conference. May 23-25, 2004, Scottsdale, AZ. 7p.

Harness, R.E. and E.L. Walters. 2003. Mitigating woodpecker damage to utility poles. Western Energy Institute and Northwest Public Power Association. November 5-6, 2003, Reno, NV. 11p.

Walters, E.L. 2001. When good woodpeckers go bad: why do they damage utility structures? Western Energy Institute and Northwest Public Power Association. October 2001, Reno, NV. 6p.

Walters, E.L. 2000. Woodpeckers 101: the basics of woodpecker biology. Northeast Pole Conference. October 2000, Binghamton, NY. 7p.

Walters, E.L. 1997. Woodpecker biology and behavior. Electric Power Research Institute. May 1997, Charlotte, NC. 6p.

Marine Mammals

Baird, R.W., Walters, E.L. and P.J. Stacey. 1993. Status of the Bottlenose Dolphin, Tursiops truncatus, in Canada. Canadian Field-Naturalist 107(4):466-480. Reprints available upon request

Walters, E.L. R.W. Baird and T.J. Guenther. 1992. New killer whale “pod” discovered near Victoria. Victoria Naturalist 49(3):7-8.


WILDLIFE BIOLOGY

Cavity-nesting Birds

I have been studying cavity-nesting birds (47 species) and mammals since 1990. To date, I have had the opportunity to report on and/or conduct research on 19 of the 22 species of woodpeckers found in North America. Field work has been conducted at research sites in Arizona, British Columbia, California, and Florida. The bulk of my postgraduate thesis and dissertation work has examined hole-nesting communities associated with woodpecker holes.

Habitat and space use of the Red-naped Sapsucker, Sphyrapicus nuchalis, in the Hat Creek Valley, south-central British Columbia

Collaborator: Edward H. Miller (Memorial University)

Upper Hat Creek ValleyRed-naped Sapsuckers are purported to be keystone species in the communities in which they are found. My MS research examined the nature in which sapsuckers use habitat and space. Using radio telemetry, I established home range estimates and documented their use of habitat as they foraged and nested. This study was part of a larger study initiated by my former advisor, Ted Miller, in 1989. Some of the publications that have resulted from this work are listed below.

Walters, E.L., E.H. Miller, and P.E. Lowther. 2014. Red-naped Sapsucker (Sphyrapicus nuchalis). The Birds of North America Online (A. Poolel, Ed.). Ithaca: Cornell Lab of Ornithology; The Birds of North America Online. doi:10.2173/bna.663b

Red-naped SapsuckerWalters, E.L., E.H. Miller, and P.E. Lowther. 2014. Red-breasted Sapsucker (Sphyrapicus ruber). The Birds of North America Online (A. Poolel, Ed.). Ithaca: Cornell Lab of Ornithology; The Birds of North America Online. doi:10.2173/bna.663a

Walters, E.L. 2004. Study identifies nest-cavity predators: woodpecker nests in British Columbia are examined. Bluebird 26:15-17.

Walters, E.L., E.H. Miller, and P.E. Lowther. 2002. Yellow-bellied Sapsucker (Sphyrapicus varius). In The Birds of North America, No. 662 (A. Poole & F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA. Reprints available upon request

Walters, E.L., E.H. Miller, and P.E. Lowther. 2002. Red-breasted Sapsucker (Sphyrapicus ruber) and Red-naped Sapsucker (Sphyrapicus nuchalis). In The Birds of North America, No. 663 (A. Poole & F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA. Reprints available upon requestUpper Hat Creek Valley

Walters, E.L. and E.H. Miller. 2001. Predation on woodpeckers in British Columbia. Canadian Field-Naturalist 115(3): 413-419. Reprints available upon request

Walters, E.L. 1996. Habitat and space use of the Red-naped Sapsucker, Sphyrapicus nuchalis, in the Hat Creek Valley, south-central British Columbia. MSc. Thesis, University of Victoria, Victoria, B.C. Canada. Erratum

Miscellaneous Research on Woodpeckers

Koenig, W.D., E.L. Walters, J.R. Walters, J.S. Kellam, K.G. Michalek, and M.S. Schrader. 2005. Seasonal body weight variation in five species of woodpeckers.  Condor 107(4):810-822.

Miller, E.H., E.L. Walters and H. Ouellet. 1999. Plumage, size, and sexual dimorphism in the Queen Charlotte Islands Hairy Woodpecker. Condor 101:86-95.

Steeger, C., M. Machmer and E. Walters. 1996. Ecology and management of woodpeckers and wildlife trees in British Columbia. Fraser River Action Plan, Environment Canada, Ottawa. 23p. Reprints available upon request

Walters, E.L. 1994. A critical review of “A methodology for surveying woodpeckers in British Columbia”. Contract report to the Wildlife Branch, Ministry of Environment, Victoria, B.C.

Radio Telemetry

I have been conducting telemetry studies for over 23 years, beginning with my postgraduate work on space use by Red-naped Sapsuckers in 1994. This was followed a year later with telemetry work in Arizona involving Red-naped Sapsuckers, Williamson's Sapsuckers, Red-breasted Nuthatches, Pygmy Nuthatches, Hermit Thrushes, and Orange-crowned Warblers. Other projects later on included research on Red-bellied Woodpeckers in Florida (1997) and California Towhees (2004-2006). In 1996 I helped coauthor a standards manual that is used by the British Columbia government for anyone initiating telemetry studies in that province. We are currently using telemetry with Hispaniolan Woodpeckers and Palmchats in the Dominican Republic in addition to nanotags with our Acorn Woodpecker population.

Andrusiak, L, E.L. Walters, T. Eliot and K. Simpsons. 1996. Standards manual for wildlife radio telemetry. Resources Inventory Committee, Ministry of Environment, Lands, and Parks, Victoria, B.C.

Wildlife Viewing Plans

Brewer's SparrowWalters, E.L. and D.R. Copley. 1991. Waterfowl use of the Martindale Flats management area. Report to the Parks & Conservation Committee, Victoria Natural History Society. Victoria, B.C.

Fraser, D.F., C. Berryman, E.L. Walters and L.R. Ramsay. 1990. Wildlife viewing plan for Goldstream Provincial Park. Contract report to the Ministry of Parks, Vancouver, B.C.

Fraser, D.F., L.R. Ramsay, and E.L. Walters. 1990. Wildlife viewing plan for Manning Provincial Park. Contract report to the Ministry of Parks, Vancouver, B.C.

Wildlife Diseases / Parasites

Wildlife diseases and parasites play important roles in regulating populations. In the publications listed below, we show that mortality due to a protozoan accounted for mortality estimates upwards of 100,000 Band-tailed Pigeons in a 2-month period. Work with haematozoan parasites of Red-bellied Woodpecker revealed that only males exhibited decreased mass and body condition with parasite loads.

Stromberg, M.R., W.D. Koenig, E.L. Walters, and J. Schweisinger. 2008. Estimate of Trichomonas gallinae-induced mortality in band-tailed pigeons, upper Carmel Valley, California, winter 2006-2007. Wilson Journal of Ornithology 120(3):603-606.

Red-bellied WoodpeckerSchrader, M.S., E.L. Walters, F.C. James., and E.C. Greiner. 2003. Seasonal prevalence of a haematozoan parasite of the Red-bellied Woodpecker (Melanerpes carolinus) and its association with host condition and overwinter survival. AUK 120(1):130-137.

Foster, G.W., J.M. Kinsella, E.L. Walters, M.S. Schrader, and D.J. Forrester. 2002. Parasitic helminths of red-bellied woodpeckers (Melanerpes carolinus) from the Apalachicola National Forest in Florida. Journal of Parasitology 88(6):1140-1142.

 

 

Birds as Hosts of Tick Pathogen Transmission

Collaborator: Holly D. Gaff (Old Dominion University), Jory Brinkerhoff (University of Richmond) ONGOING RESEARCH

Avian hosts likely play an important role in tick dispersal. Several species of ticks in eastern Virginia have shown sudden and dramatic range shifts. These tick species act as vectors of human disease and thus a complete understanding of the role that avian hosts play in these range shifts is of critical importance. Our research examines how both resident and migratory avian species act as hosts to different tick life stages at various times of year. Our sampling occurs at several key locations in Virginia in order to map the progression of new tick species and the pathogens they carry as they move deeper into Virginia.

Heller, E.L., Wright, C.L., Nadolny, R.M., Hynes, W.L., Gaff, H.D., and E.L. Walters. 2016. New records of Ixodes affinis parasitizing avian hosts in southeastern Virginia. Journal of Medical Entomology. DOI 10.1093/jme/tjv175 2016.

Eric L. Walters © 2017 All rights reserved.