Annual lab peony trip


Every year, we make the (pretty short!) walk to the Arb to see the peonies. This year, we didn’t quite make it for peak peonies, but there were still lots in bloom!

view of the back of someone in a purple shirt looking at an information card about peonies. Many peonies in bloom are in view beyond the person with the back to the camera, as are two other lab members

The 2022 field season has begun!


Our field season has begun! And it turns out the weather gets better every day of field season — this trend will continue through November, right?

Day 1: We started sampling on June 1st which was, unfortunately, a rainy day, but that didn’t stop the field crew!

Siobhan heading out to the deep spot on Crooked (W) in the rain.

Day 2: The weather was somewhat nicer — no rain, but still cloudy.

Teresa collecting a water sample with the van Dorn bottle.
Sun collecting a plankton tow.

Day 3:

Beautiful weather for Noah’s first day in the field!

Noah giving a thumbs up to the beautiful weather for his first day in the field!

We’re looking forward to field season, even if the weather isn’t always as nice as it was on day 3!

Kristel receives department JEDI award!


Congratulations to Kristel, one of two recipients of this year’s departmental Justice, Equity, Diversity, and Inclusion (JEDI) award! Kristel received the award specifically for her work on Feria de Ciencias, which is an annual event that engages local primary school students about science in Spanish. Kristel has been a principal organizer of this, working with the En Nuestra Lengua after school program (where Kristel also volunteers!) to bring it to fruition.

In addition to her work with Feria de Ciencias, Kristel has been highly involved in multiple other JEDI efforts while in grad school. This has included: department service focused on JEDI issues (including serving on the department’s Diversity Committee), helping to organize the annual BioBlitz in the Detroit area, helping with EcoDia (an event held in Mexico for children ages 5-12 from rural communities in Chiapas), and via thoughtful, supportive mentoring of students from underrepresented groups.

Kristel is highly deserving of this award and we’re very happy she is receiving this recognition! Congrats, Kristel!

Stations at Feria de Ciencias (photo courtesy of Kristel Sánchez)

Kristel smelling ants with an EcoDia participant!

New article on virulence evolution!


We have a new article exploring virulence evolution during a naturally occurring parasite outbreak! This paper includes work led by Camden Gowler as part of his dissertation work, as well as Haley Essington’s undergraduate honors thesis project. The study tracked an outbreak of the virulent bacterial parasite Pasteuria ramosa in a lake population; this was a large outbreak, with ~40% of the population being infected at the peak of the epidemic. Not surprisingly, considering the size of the outbreak of this sterilizing parasite, host density declined precipitously during the epidemic.

In addition to monitoring the epidemiological dynamics, Camden collected host and parasite from different time points during the outbreak. Camden and Haley then led a study that exposed Daphnia clones to parasites isolated at different time points. We did not detect any significant changes in host resistance or parasite infectivity. We also did not find evidence of shifts in two measures of parasite virulence, host lifespan and number of clutches produced by hosts. To our surprise, the parasite evolved over the course of the epidemic to produce significantly fewer spores in infected hosts. You can read more about this in the article which is now available online at Evolutionary Ecology; it’s open access, so free for all to read!

lake with plants in foreground and trees in distance
A photo of Little Appleton Lake, which was the focus of the study in the new Gowler et al. Evolutionary Ecology paper. Photo credit: Libby Davenport

Libby is now a PhD Candidate!


Congratulations to Libby on completing her qualifying exams! During Fall semester, she gave a presentation about her research, wrote a dissertation proposal, and took her oral exams — while also collecting and filtering almost 1000 water samples during field season! Libby is now a PhD candidate and is looking forward to analyzing all those samples and trying out some winter sports.

Libby out sampling (photo credit: Siobhan Calhoun)

New paper on the visual ecology of selective predation on infected hosts!


Former Duffy Lab postdoc Nina Wale (who is now an assistant professor at Michigan State) is lead author on a new paper in Ecology and Evolution that explores whether visual symptoms of infection can drive selective predation on infected hosts. This has been the leading hypothesis for why bluegill sunfish feed selectively on Daphnia that are infected with parasites, but the hypothesis had not been rigorously tested, and it’s possible that other factors (e.g., differences in swimming behavior) could drive the selective predation. The field of visual ecology has revealed that, because of mismatches between human and animal visual systems, humans can overestimate the importance of visual signals that mediate ecological interaction. For this reason, we took a “predator’s eye view” to try to understand whether, and by how much, altered visibility of infected hosts alters predation.

In this study, we used a model of the bluegill visual system, measurements of the light environment in natural lakes, and quantification of infection-induced changes in Daphnia transparency to evaluate the hypothesis that visual symptoms of infection drive selective predation. We found show that three common parasites, Metschnikowia bicuspidataPasteuria ramosa, and Spirobacillus cienkowskii, decrease the transparency of Daphnia, rendering infected Daphnia darker against a background of bright downwelling light. This change in brightness contrast means that bluegill can see infected Daphnia at greater distances than uninfected Daphnia—between 19% and 33% further, depending on the parasite. Thus, visual symptoms of infection can explain selective predation on infected Daphnia. Or, put differently: unhealthy hosts are less stealthy hosts.

This work included the honors thesis work of former Duffy Lab undergrad McKenna Turrill, and was a collaboration with Becky Fuller (Illinois) and Sönke Johnsen (Duke).


Welcome Kris, Sun, and Teresa!

From Left to Right: Teresa, Kris, and Sun

In August and September, three new folks joined the lab! Kris McIntire and Syuan-Jyun Sun are new postdocs in the lab. Kris joins us from Illinois State University, where she completed her PhD. Sun received his PhD from Cambridge, then did a postdoc at National Taiwan University. Teresa Sauer is a new PhD student in the lab, joining us from Fairfield University in Connecticut. We’re very excited to have them in the lab!