Margaret and Dave setting up nest box




Biology Program

Penn State Erie, The Behrend College        

Dr. Margaret A. Voss

Associate Professor of Biology

Ph.D., Biology

Syracuse University, Syracuse NY, 2001


M.S., Environmental and Forest Biology

SUNY College of Environmental Science and Forestry, Syracuse NY, 1995


B.S., Environmental and Forest Biology

SUNY College of Environmental Science and Forestry, Syracuse NY, 1992



Teaching Interests:

Behavioral Ecology, Physiological Ecology, and Comparative Anatomy.

I believe students must be given opportunity to practice science if they are to become scientists, thus I incorporate student-formulated hypothesis testing into labs wherever possible and use student generated questions as the basis for class discussions. I believe that every student brings a wealth of information into the classroom. I try to tap into that resource through interactive Socratic-style discussions whenever possible.

Research Interests: 

Behavioral Ecology and Physiological Ecology

I am a physiological ecologist; I study the relationship between internal (physiological) and external (ecological) environments, and the adaptive mechanisms that allow animals to function under extreme conditions. I attempt to understand the evolutionary significance of non-optimal behavior, or so called Darwinian Puzzles, through my work on avian reproductive behavior and physiology. I am interested in why many small, migratory passerines nesting in cool North American environments are single sex incubators. In almost 80% of non-passerine families, both parents incubate. However, in approximately 62% of all passerine families, only the females incubate. This is an evolutionarily derived behavior. Constant temperatures are thought to be optimal for avian embryonic development. This requirement is clearly impossible if an incubating female regularly leaves the nest to forage, allowing eggs to cool to sub-optimal temperatures. My projects quantify the constraints behavioral thermoregulation places on embryo development and parental energetics. Toward this end, I use biophysical models of egg thermodynamics coupled with optimality models to test ideas about non-optimal foraging and incubation behavior.

Ongoing Projects:

Optimal foraging behavior, avian energetics and embryonic development – I am primarily interested in the trade of between parental self-maintenance during incubation and maintenance of adequate egg temperature for proper embryonic development.

The influence of embryonic development on parental behavior. Intermittent incubators must balance internal energy demands with the thermal requirements of the eggs. Egg temperature depends on three components of the incubation session-recess cycle: 1) egg cooling during recesses, 2) egg heating and 3) equilibrium temperatures during sessions. Dr. Caren Cooper (Cornell Lab of Ornithology) and I are testing hypotheses about the influence of day length and ambient temperature on the trade-offs between mean egg temperature and foraging time within the context of latitudinal variation in parental investment. We use biophysical models to predict that heat flux from eggs as embryonic development proceeds. The dynamic aspects of parent-embryo trade-offs highlight the need to view incubation along a continuum of thermal contributions of parental care rather than as an all-or-none process.

Does variation in microclimate actually benefit developing avian embryos? When animals are kept in captivity, they are often maintained at what we believe to be optimal environmental conditions. If pathogens and their host organisms are in a continual evolutionary struggle, an arms race of sorts, then constant environments should favor the pathogens. Bacterial generation times are much shorter than those of vertebrate species, allowing for rapid multiplication under constant environmental conditions. Thus, what we perceive as variable and therefore “non-optimal” environmental conditions might actually be beneficial to some host organisms. I believe this might contribute to the phenomenon of intermittent incubation, which is clearly less efficient than constant incubation from the point of view of the developing embryo. I currently collaborate with colleagues at Behrend to test this idea. We believe that nest microclimate is maintained through structural and behavioral means to augment embryonic development. The choice of plant material used in construction, the content and structure of the nest lining (feathers, fur, grasses), and parental incubation behavior may interact to regulate the microbial flora of nests. Maintaining beneficial microbes while  minimizing pathogenic strains may be an important factor in decreasing embryonic mortality. We are currently working to 1) characterize the microbial communities present in nests and eggs of several species of North American birds, 2) investigate correlations between species specific nest structure and microbial flora, 3) determine if microbial communities change in composition before and after nestling fledge, 4) determine if microbial communities change in composition when nest microclimate is altered, and 5) document changes in parental incubation behavior and embryonic mortality associated with composition changes in microbial communities in nests. 


Recent Publications:

Cooper, C., M. Voss, D. Ardia, S. Austin, WD. Robinison. (in press). Light increases the rate of embryonic development: implications for latitudinal trends in incubation period. Functional Ecology doi: 10.1111/j.1365-2435.2011.01847.x.


Schnars, J.L., M.A. Voss, J.R. Stauffer. 2011. Hatching Success of PCB Injected Snapping Turtle (Chelydra serpentina serpentina) Eggs. Environmental Toxicology and Chemistry, 30 (4):915–919.


Voss, M.A. and C.B. Cooper. 2010. Using a free on-line Citizen Science Project to Teach Observation and Quantification of Animal Behavior. The American Biology Teacher 72 (7):437–443. ISSN 0002-7685, electronic ISSN 1938–4211.


Voss, M.A., D. Shutler and J. Werner. 2010. A hard look at blood-sampling of birds. The Auk 123 (3): 704-708.


Cooper, C.B., M.A. Voss, and B. Zivkovic. 2009. Extended laying interval of ultimate eggs of the Eastern Bluebird. The Condor 111(4):752-755.


Ardia, D.R. , J.H. Pérez , E.K. Chad, M.A. Voss , and E.D. Clotfelter. 2009. Temperature and Life History: Experimental Heating Leads Female Tree Swallows to Modulate Egg Temperature and Incubation Behavior. Functional Animal Ecology, 78:4-13 (doi: 10.1111/j.1365-2656.2008.01453.x).


Voss, M.A. , M.A. Rutter, N. Zimmerman, and K. Moll. 2008. The Adaptive Value of Thermally Inefficient Male Incubation in the American Barn Swallow (Hirundo rustica erythrogaster). The Auk 125 (3):637-642.(doi: 10.1525/auk.2008.07046)


Voss, M.A., Hainsworth, F.R., Ellis-Felege, S.N. 2006. Use of a New Model to Quantify Compromises between Embryo Development and Parental Self-maintenance in Three Species of Intermittently Incubating Passerines. Journal of Thermal Biology, 31(6):453-460.


Hunnicutt, DW, Cingolani, J, and M.A. Voss. 2005.Use of mtDNA to Identify Genetic Introgression among Related Species of Catfish. In press, Journal of Great Lakes Research 31(4):482-491.


Hainsworth, FR, and M.A. Voss. 2002. Intermittent Incubation: Predictions and Tests for Time and Heat Allocations. Chapter 15 in Avian Incubation: Behaviour, Environment and Evolution, D.C. Deeming, editor. Oxford Ornithology Series, Oxford University Press, Oxford, England. ISBN:0-19-850810-7


Voss, M.A. and F.R. Hainsworth. 2001. Relatively Simple, Precise Methods to Analyze Temperature Transients in Ectotherms. Journal of Thermal Biology. 26:121-132


Hainsworth, FR, T Moonan, M.A. Voss, KA Sullivan, and WW Weathers. 1998. Time and Heat Allocations to Balance Conflicting Demands during Intermittent Incubation by Yellow-eyed Juncos. Journal of Avian Biology. 29:113-118


Nueman, J, DL Pearl, PJ Ewins, R Black, DV Weseloh, M Pike (né Voss), and K Karwowski. 1997. Spatial and Temporal Variation in the Diet of Double-crested Cormorants (Phalacrocorax aurtius) Breeding on the Lower Great Lakes in the early 1990's. Canadian Journal of Fisheries and Aquatic Sciences. 54 (7):1569-1584






















Penn State Erie LogoStudents taking bacteria samples from eggs in fieldStudent in the fieldBanding Black-capped Chickadees in the field, early springStudents taking bacteria samples from eggs