Rachel Anderson

What do you do when your predator is also your competitor?


Animals, Aquatic, Behavioral Ecology, Conservation, Ecology, Evolution, Evolutionary processes, Experimental, Field, Lab, North America, Observational, Restoration


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Other Resources

Anderson, Rachel B., and Sharon P. Lawler. 2016. Behavioral changes in tadpoles after multigenerational exposure to an invasive intraguild predator. Behavioral Ecology 27:6 1790-1796

Presentation Notes

Researcher’s Background

Rachel is a herpetologist and conservation biologist in Monterrey, California. She is “currently teaching biology at community college, where I can focus on teaching and learning, and getting as many people excited about biology as I can. I’m also working as a biological consultant doing amphibian surveys for local parks, so I can continue in the conservation work that I love. Sometimes these two intersect and I can mentor local high schoolers or college students in field research.”


PB: Why did you become a biologist?

RA: I love living things and the natural world, and asking and answering questions about it seemed/seems very natural to me.


PB: What is your favorite part about your job?

RA: I love being outside, handling animals, and I love getting other people excited about it too.


PB: What obstacles have you overcome to get where you are?

RA: Not many other than self-doubt and impostor syndrome.


PB: What advice do you have for aspiring biologists?

RA: Introduce yourself to people who are studying things you’re interested in, and try to get research opportunities (you have to ask for the things you want).


PB: Do you feel that any dimension of your identity is invisible or under-represented/marginalized in STEM?

RA: Scientists aren’t supposed to be racked with anxiety, depression, self-doubt, etc., yet so many of us, including myself, quietly are. It would be helpful to the community if we could discuss and acknowledge these things more openly. Also, people don’t necessarily expect a tiny woman to be a field biologist (although this good old boys club mentality seems to be in decline, I still see older men only associating with other older men, holding positions of power, etc, at herp and ich meetings) so it can take extra work to assure people that I’m just as capable of being outside in the elements, working hard, generating interesting ideas, etc. This is kind of minor but people also don’t expect biologists to be vegans or to have strict ethics around the treatment of animals, and seem to assume that we’ll be fine with dissecting animals, with sacrificing them at the end of experiments, and it’s regarded with hostility even when we ask if there might be a different way of doing things (and isn’t that the point of scientific inquiry??) 

Research Overview

Take home message of study

California red-legged frogs that evolved in the presence of invasive bullfrog developed a response to both the predatory and competitive effects of invasive bullfrogs, potentially mitigating the impacts of their introduction.

Study system

California Red-legged Frog (Rana draytonii) larvae in the researcher’s hand at a field site. Fairly late stage; no longer subject to predation pressure from bullfrogs.

Key Research Points

Main figure

Tadpoles of Rana draytonii (California Red-legged Frogs) that co-evolved with bullfrogs (syntopic) respond to chemical cues of bullfrogs (their predators and competitors) initially by hiding, and later, after reaching a size refuge, increased foraging behavior. Tadpoles that were naive to bullfrogs (allotopic) ignored the chemical cues. Thus, syntopic tadpoles evolved a response to both the predatory and competitive effects of invasive bullfrogs, potentially mitigating these impacts.

Societal Relevance

This research is relevant to the protection of California’s natural heritage. The California red-legged frog is a traditional food source for indigenous people. Also, this work is relevant because amphibians are bioindicators, and endangered species as umbrella species for conserving and restoring native habitats

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