This is the first in our mini interview series with the Biology department’s weekly seminar speakers. Apart from a few research-oriented questions, through this blog, we hope to share a little of their lives, their stories and motivations. And perhaps learn and let ourselves be inspired along the way.
This is ‘Small Talk’ with Lauren Pintor from Ohio State University who gave a talk on 23rd September, 2014, on her research with invasive prey and native predators.
Q: Do you ever think of invasive species as the ‘good guys’? What is the general perception of invasive species?
LP: I think there has been a lot of literature lately trying to advocate trying to take a more balanced perspective with invasions, to understand both sides, because there are positive interactions that can occur between invasive and native species. And so, I took itto heart when a series of papers came out on that, and a lot of work that I’ve been doing recently has been looking at interactions between non native species as prey and their influence on native predators. What I’ll talk about in my seminar is a big meta analysis recently completed that shows that a lot of non native species have a net positive effect on native predators. But, it is a two-way interaction and we caution against that message being “oh! non native species are good for native predators!”, because there could be elevated native predator populations which could in turn have negative consequences for other native prey. So, even though it might be positive in one context, you pull other players into it, it could be negative. Understanding and taking a balanced approach, both how an interaction can be positive and negative, allows us to make predictions about ultimate community level consequences. There are a lot of rising cases where you’ve got species that have been in decline that are adapting to novel prey sources and are rebounding as a consequence. For example, the Lake Erie water snake is a threatened species, and has adapted to using invasive brown gobies as prey, leading to a big increase in the water snake population in the lake and delisting of it as a consequence. Down in Georgia, there is a map turtle that eats fresh water mussels, that are imperilled groups worldwide, but these systems have also been invaded by a non native Asian clam and the turtles have switched over to them, and we are starting to see an increase in the map turtles.
I think what you ultimately define an invader as positive or negative is not just a result of an ecological outcome of the interaction, but what I’ve learned working with invasive species is that there are a lot of social, human, historical factors that go along with invasions and how people view them. Some don’t think they’re a big deal, some think they’re really bad. So there is a lot of personal perception that goes into that definition. From an ecological perspective, I think trying to take a balanced perspective and not just thinking them as negative is very good from the perspective of being able to predict long term consequences and changes in the community where you can map out all the outcomes and interactions.
Q: Is there some kind of predator naïveté behaviour, like we see in prey that are introduced to novel predators?
LP: When it comes to predator-prey invasions in particular, we have a very one-sided perspective – the impact of introduced predators on prey. We know how decimated native bird species have been in Guam as a consequence of the brown tree snake. When (our very own) Steve Lima proposed the predator-prey naïveté hypothesis, it was so influential and a very useful framework for thinking about and predicting consequences of predator invasions, but the flip side of the interaction has been largely kind of overlooked. So, yes, from the perspective of a non native species coming in that could be a prey, native predators might be equally as naive so that could contribute to that prey’s escape from its natural enemies and could be why it becomes invasive. But that relationship can change over time as species learn and get more experience and the naïveté goes away.
It might also depend on traits of the native species prior to invasion, so for example, if you were eating a prey that were very similar to this non native species coming in, you might have the right sensory modality or what not to detect that as prey, the right foraging skills, the right predatory tactics to go after that as prey. So you’re not naive. But then there are others maybe, where if your native food source is very different from the new potential prey, then maybe you are equally as naive. So I think it definitely should and could work both ways, but what I’ll talk about today is the importance of individual variation within a native predator-prey population that can influence the outcome of that interaction. So you may have some individuals that are more naive than others, again depending on aspects of their prior diet, aspects of their personality that might make them more or less neophobic, scared of novel things, and in turn that should influence the outcome of that predator-prey interaction.
Q: In working with invasives, have you interacted with non-academics (policy makers, economists, wildlife managers, etc) to discuss the applicability of your findings?
Follow-up Q: How long did it take for your hair to grow back once you pulled it all out?
LP: (Laughs). Well, now being in the School of Environment and Natural Resources, and having very tight connections with state agencies and our school having a very applied mission, I’m trying to make a more active effort to explore how I can make my work applicable to on-the-ground management, and it’s challenging. So far, I guess I haven’t had too many hair pulling-out experiences. When I worked on an endangered dragonfly species, I worked very closely with the USFW and the Endangered Species Recovery Team, and they were very good at taking our information to heart. For example, we were trying to demonstrate metapopulation dynamics on the species and that we should use metapopulation dynamics theory to set up delisting criteria for the dragonfly. So it’s not just that you have recovery of population x but that population has to have a particular spatial structure in order to say that it’s a stable population to help delist that species. Trying to convince managers that that was the way to go as opposed to “well, we just know when there’s probably enough that we can delist them”, that was kind of challenging. Trying to show them empirically that this is what’s actually going on, it’s not just some theoretical construct we’re putting around a species, that these population dynamics are really important for persistence, and just because this patch here doesn’t have many, it can be removed. No, that patch is still important. With invasive species, … for my dissertation I worked with an environment consulting firm that had been contracted to do a lot of work on endangered crayfish that was being outcompeted by the invasive crayfish, and it was very clear that one of the main reasons the species was in decline was because the invader was just kicking its butt. So there was favourable repsonse to our recommendation for how to manage the invasives, whether it was a big eradication effort as opposed to investigating and installing barriers for dispersal and things like that. There, I didn’t pull my hair out too much I think, it was kind of fair.
Q: What is your favourite comic?
LP: Umm.. Sadly, no.. I don’t really read comics. (After some prompting), I do like PhD comics!
Q: What/who has been a major inspiration for where you are right now? They could be books, people, a mind-blowing paper, an animal, or anything.
LP: A big influence to me in terms of my career was a tropical ecology professor at Illion named Carol Augsperger. She was influential, more so not anything to do with research, but just her drive and passion, and her interest in students. It was really inspiring and encouraging at a time when I was not sure what field of work I wanted to go into and so I always think of her a lot, especially when I’m teaching and just thinking about the impact she made on me in the classroom. It keeps my motivation when students make me want to pull my hair out, that I might be able to have that kind of same influence on one student that she had on me which really set my trajectory in ecology. I think if it wasn’t for her and her class, I would have actually gone to culinary school!