Fifth-year doctoral candidate Elizabeth Postema of the lab of community ecologist/professor Louie Yang, UC Davis Department of Entomology and Nematology, will be presenting her exit seminar “Antipredator Color and Behavior in Swallowtail Caterpillars” at 12:10 p.m., Thursday, May 25 in 357 Hutchison Hall and on Zoom.

Postema studies the role of animal coloration in predator-prey interatctions with a special focus on color-changing species. She works with both live and artificial swallowtail caterpillars (family Papilionidae) in the field.

She is the lead author of a review article, "Color Under Pressure: How multiple Factors Shape Defensive Coloration," published in June 2022 in the journal, Behavioral Ecology.

The abstract: Behavioral ecologists have long studied the role of coloration as a defense against natural enemies. Recent reviews of defensive coloration have emphasized that these visual signals are rarely selected by single predatory receivers. Complex interactions between signaler, receiver, and environmental pressures produce a striking array of color strategies—many of which must serve multiple, sometimes conflicting, functions. In this review, we describe six common conflicts in selection pressures that produce multifunctional color patterns, and three key strategies of multifunctionality. Six general scenarios that produce conflicting selection pressures on defensive coloration are: (1) multiple antagonists, (2) conspecific communication, (3) hunting while being hunted, (4) variation in transmission environment, (5) ontogenetic changes, and (6) abiotic/physiological factors. Organisms resolve these apparent conflicts via (1) intermediate, (2) simultaneous, and/or (3) plastic color strategies. These strategies apply across the full spectrum of color defenses, from aposematism to crypsis, and reflect how complexity in sets of selection pressures can produce and maintain the diversity of animal color patterns we see in nature. Finally, we discuss how best to approach studies of multifunctionality in animal color, with specific examples of unresolved questions in the field."

On the Yang lab website, Postema says: "After growing up in Ann Arbor, MI, I relocated to Denison University in Granville, OH to pursue my undergraduate degree. Though I began my college career as a studio art major, I quickly found that biology was my calling. I studied a wide range of systems throughout college, from lemon sharks and rock iguanas to deciduous shrubs. I am now conducting research on insect color and behavior in the Animal Behavior program at UC Davis. When I'm not obsessing over bugs, I can usually be found spoiling my pet chickens, drawing sketches for The Ethogram, or writing poetry."

At UC Davis, Postema is a member of the Animal Behavior Graduate Group.

"Elizabeth will be starting a great postdoc position studying beetle coloration at the Field Museum in Chicago," Professor Yang announced.