Interview with Liana Zanette

Written By: Mariana, a Junior Giraffe Club member

Dr. Liana Zanette is a Professor of Biology at Western University in London, Ontario where she teaches Conservation Biology and Population Ecology. Liana’s research examines the relationship between predators and their prey with a focus on the ‘Ecology of Fear’.

Liana’s research has been featured in several documentaries including “Nature’s Fear Factor”, “Animal Espionage”, “Spying on Animals”, and “Cat Crazed”.

Liana received her BSc in Psychology from the University of Toronto and an MSc in Biology from Queen’s University. After that, she did her PhD in Australia where she conducted research on forest fragmentation and its effects on birds. This was followed by a Killam Postdoctoral Fellowship at the University of British Columbia and then a faculty position at Western University. Liana’s research takes her to many places in the world where she works on a variety of amazing animals from birds and bears in Canada, cougars in California, wolves in Poland, marsupials in Australia, to wildlife in Eswatini and South Africa.

Junior Giraffe Club member Mariana asked Liana some questions about her role in her experiences, her research, and more:

1. What have been some of the most surprising findings from your research on fear in wildlife?

What I consider most remarkable about the findings from our research in the Ecology of Fear is the extent to which humans are the most feared predator on the planet. The magnitude of the effect is staggering whereby wildlife are at least two times more afraid of humans than the next largest predator in any system we have sampled in the world. The effect is also incredibly comprehensive across communities impacting wildlife in Africa, Asia, North America, and Europe. 

When we think about what this fear of humans means, it really reveals a whole new dimension to the environmental impacts that humans have on the planet. Certainly, we know that habitat loss, climate change, and other human-caused factors alter landscapes and reduce biodiversity. What our research indicates is that just by being out on the landscape, humans are having an enormous effect on animal behavior because wildlife are terrified of us, recognizing humans as extraordinarily lethal predators. And, because there are over 8 billion of us in every nook and cranny of the planet, the scale of our effect is literally global. 

The ecological relevance to these changes in animal behavior is that they are costly for wildlife. Scared prey typically eat less; it is not possible to have your head up looking for predators and your head down looking for food at the same time for example, and wildlife will also avoid nutritious patches of food when they think their predators are lurking nearby. We have demonstrated in other field manipulations on birds, large carnivores, and medium-sized carnivores that because wildlife miss meals to avoid becoming a meal they produce 53% fewer offspring over the course of a breeding season. We have also demonstrated that fear of predators affects multiple different species thereby causing cascading effects down the food chain. 

2. How do you see the field of ecology evolving in the next decade, particularly in the area of predator-prey interactions?

I foresee that the field of ecology will now better incorporate the role of fear when it comes to understanding how predator-prey interactions work. The traditional view of predator-prey interactions that we typically read in textbooks, is that the only way predators can affect their prey is by killing them. And this makes sense; you have two zebras, a lion eats one, you have one zebra left in the population. The obviousness of this effect of eating prey is one reason why the fear that predators inspire in prey, and the behavioral responses of those prey to avoid being eaten, was considered to be inconsequential.  

We know now that fear of predators can be as or more important as the direct killing that predators do when it comes to prey population numbers and communities in the food chain.  In other words, predators were traditionally considered to have a single effect on prey – they eat them.  What we now better understand is that predators actually play a dual role in that they eat and scare prey and each of these effects adds up to big ecological changes. 

Let’s think about what this means to the phenomenon we have seen across the globe.  For example, it has long been noted in ecology textbooks that when predators are removed from ecosystems, ecosystems often collapse. When a top predator is removed that has a positive effect on their prey which then can have a severe negative effect on the prey’s food further down the food chain, often turning healthy ecosystems into degraded ones. Sometimes, when predators are restored, we can see a reversal of this negative impact and an improvement in ecosystem health. This and many other examples of ‘trophic cascades’ suggest that predators can have effects on not just their prey but all tiers of the food chain, far more than we would have expected from direct killing alone. We can now better understand why predators play such a pivotal role in nature because they have not one, but two impacts; eating prey and scaring them. 

3. According to Ecology of Fear, you have many collaborative projects. Can you tell us about one of them?

Photo of a Reticulated Giraffe taken by Dr. Zanette. “Quite different from those we see in South Africa. They have very vibrant contrast of white in between the tan patches and they are just so gorgeous.”

The collaborative project we are most currently working on is in Florida. We work with the Florida Fish and Wildlife Commission on the Panhandle of Florida. Part of the mandate of the FFWC is to protect shorebird population numbers. 

The issue here is that shorebirds around the globe have been declining in numbers. Today, the main mechanism is thought to be due to medium-sized carnivores (like coyotes and raccoons in North America for example). Because humans have exterminated many large carnivores (and large carnivores love to eat medium-sized ones) in many places in the world, medium-sized carnivores now do not need to worry about being eaten. As a result, they can be fearless which means that they can feed as much as they want wherever they want thereby having this negative effect on the ecosystem. This same situation is occurring in Florida where medium-sized carnivores venture onto shorebird nesting habitat and eat shorebird eggs, chicks, and sometimes the adults. This is leading to declining shorebird population numbers. 

Last year in Florida, we established with one of our ABR experiments (Automated Behaviour Response systems), that medium-sized carnivores in Florida fear humans most (of course). This year, we have set up speakers broadcasting vocalizations facing toward medium-sized carnivore habitats. Behind our speakers is shorebird nesting habitat. Over the entire breeding season, our speakers broadcast either human vocalizations or a non-scary control (frogs) at that interface between shorebird nesting habitat and medium-sized carnivore habitat. The idea is to see whether we can turn intruding predators onto shorebird nesting habitat when frogs are playing, into retreating predators when humans are being broadcast, thereby protecting shorebird nests and improving shorebird numbers. This work has just been completed this month, so we will be busy over the next months with data analyses.

4. You mentioned at our get-together that you are looking at whether fear can be used as a conservation tool. What primary goals do you hope to achieve with your current research projects?

While it is incredibly interesting and exciting to discover that wildlife around the globe fear humans most, it is also incredibly depressing because there are so many of us, everywhere. The impact of humans on wildlife is enormous. In addition to animal behavior, we also focus on conservation biology in my lab. Humans have created so many conservation issues that it is difficult not to get depressed. But, the first rule of conservation biology is that you can never get depressed, otherwise, you will not be able to forge ahead; but forging ahead is an absolute necessity. 

So, in an attempt to try and make the fear of humans a little less depressing, we are sort of turning it on its head and are conducting experiments to establish whether we can use the fear of humans as a conservation tool; to mitigate the damage that humans have done. We have several projects on the go but the general idea is to use the sounds of humans talking calmly, in locally used languages to see whether we can scare prey away so as to benefit their prey as in the experiment I described in Florida above. In another experiment, the idea is to play human vocalizations in areas of high poaching of rhino.  We know from our work in South Africa that rhinos fear humans much more than they fear even lions.  Consequently, if we make rhinos think that there are humans around, we may be able to keep them out of high poaching areas so that they simply cannot be poached. 

5. What advice would you give young researchers interested in pursuing a career in ecological research?

You have to start with a super-charged interest in ecology and that is a no-brainer for the Junior Giraffe Club. It is also quite important to study the ecological literature well so that you are up to speed on how scientists currently understand how nature functions. This can sometimes be reflected in good grades which do become important as students move up the ranks. 

I would also suggest that it is incredibly important to get some research experience.  Fieldwork can be very difficult. It is demanding and entails a lot of hard work and it is often physically uncomfortable while at the same time being extremely rewarding. It is not always for everyone. By going out there and doing research, you will have a better idea as to how well it suits you. This also allows you to learn all the techniques and tools of the trade that you will need to know to carry out your own research project one day. 

I would also add that in addition to designing an experiment and carrying it out in the field, research also can entail a lot of somewhat boring tasks – pipetting if you have to run assays in the lab; quantifying the behavior of wildlife from 15,000 videos frame by frame as we typically do – but these tasks are all part of being a researcher.  Once the data are all in, then comes the months spent in statistical analyses. All data sets sit there doing nothing until the scientist uncovers the story that they are telling us. That is part of our job and it requires a lot of thought and consideration. But it can be a lot of fun too to put together the pieces of the puzzle that will then reveal the overall picture.  That picture brings us closer to a more complete understanding of nature. How cool is that?

Finally, one must learn how to be a good writer and speaker so as to communicate your results to the scientific community and the public at large. I sometimes find that while many students are very interested and really good at the fieldwork, what makes or breaks a career in research is following the experiment through all the way to publication to ensure that the results of your work are getting out there.  This is the only way science can progress. We also owe it to our government and/or other funders who provide the finances to get a research project done.