“For me, nature doesn’t just mean having a vast catalogue of species around us, but what truly fascinates me is how everything is interconnected and interdependent.”
Dennis Rödder at his workplace at the Museum Koenig Bonn. © LIB, K. Meusemann
As the curator of herpetology at the Museum Koenig Bonn, he is particularly fascinated by reptiles and amphibians. As a researcher, he has an eye for the big picture, which is why he is especially interested in the complex relationships in nature. In the interview, he talks about what we can all do to better protect biodiversity right in our own backyard and where he started to make a difference.
When was it clear that I would become a biologist professionally?
Actually, it was very clear very early in my life. As a child, I spent a lot of time in nature and explored various groups of animals. I also got in touch with the first professional associations for amphibians and reptiles at a very young age because I attended various lectures, which then drew me further into the field of biology. In addition, I did my first internships at the Museum Koenig Bonn before completing my high school diploma.
What aspect of your daily work is your highlight?
First, the collection itself and second, my interaction with the collection, colleagues, and students in research and teaching. It is the diversity and the interconnectedness of everything that excites me about my work at the LIB. I also regularly receive inquiries from authorities that lead me to new research questions. This, in turn, connects back to the students because some of them work on these tasks as part of their master’s theses, which I supervise. In terms of my research, I value the interactions with colleagues and students in which we jointly develop research questions. It is always exciting to arrive at results that no one really expected before. We accompany our doctoral students over such a long time, sometimes more than ten years, and it is great to see how they, as well as our joint research, continue to evolve.
What does nature mean to you personally?
It is difficult to confine it to a single feeling because, for me, it’s more than the sum of its parts. Nature, for me, means not only having a vast catalogue of species around us but what fascinates me, especially, is how everything is interconnected and interdependent. This complexity is something you cannot really imagine, and it is hard to grasp when you consider how many levels everything is interconnected. How stable it can be on one hand, but how fragile it is on the other hand in the face of certain disturbances.
Where is your favourite place in nature?
There are several. In 2005, I went to Brazil for a museum course. It was supposed to be about ornithology, but I was always focused on amphibians and reptiles in the evenings. The exciting thing was that we stayed in a small guesthouse with a few ponds, and every evening new species emerged, new amphibian species. A year later, I returned there for my diploma thesis. I identified 109 different species in just one urban area – a world record. It was extremely unique because there’s nowhere else in the world where there are so many amphibian species in such a small area. Now I have transferred this experience to my courses: Once a year, we go on an excursion to the Red Sea, we go diving and snorkelling, conduct behaviour experiments, and get to know the habitat around the coral reef more closely. Here, we find new species every day, no matter how often we dive. I just returned from there two weeks ago, and in total, we have been there eight times now. On the first day, we saw species that we had never observed in those places before. This complexity shows how dynamic it is, how many species there are, and how many dependencies exist between them. Moreover, that is what I am trying to convey.
Crabs, fish, butterflies: Who do you have a personal affection for and why?
Hmm, that is a tough question. Not specific species come to mind for me, but rather their adaptations to different environments that fascinate me. For example, you see a frog sitting in a pond, and it might seem like that’s it. However, if you look closely, you will find some quite bizarre lifestyles or incredibly diverse reproductive cycles. I find this diversity particularly exciting, so that each species, even if it initially seems normal and perhaps common, exhibits its very own behaviours that make it unique. The researcher in me wants to know: In which habitats can they be found? How are their lifestyles and behaviours adapted to each other? For example, in South America, a frog lives in ant nests. Normally, the ants would eat any other species. However, this frog has chemical mimicry that disguises it so that the ants do not even notice it. It is these forms of adaptation that I find so fascinating.
How do you explain the concept of biodiversity to children or older individuals?
It is a very complex, sometimes even a somewhat cumbersome term. So, I’ll try to put it in a visual way: When we walk across a meadow in the summer, we see many individual species. But if we look in detail, we can find many relationships. We find the spider that eats an insect, then a bird that eats the spider. We find all interconnections that we have right in front of our doorstep, and all of this together is biodiversity. Therefore, it is really more than just the sum of individual species; it also includes all these networks, dependencies, temporal changes, and dynamics.
What do you hope people will associate with the LIB in ten years?
On one hand, as a point of contact for all questions about nature, ecosystems, and biodiversity, but also as a provider of solutions. As an institution that advocates for the main problems we currently face – insect decline, overall biodiversity loss, and habitat fragmentation. I hope that we can actually offer regional solutions here and lay the foundations for policy improvements.
What do you consider the greatest challenge in the field of environmental protection?
In essence, it would be to identify key areas at the European level to maintain the connectivity of habitats. Improving microstructures, so-called green and blue infrastructures, as defined by policy. For example, we have already started with things like wildflower strips or hedgerows in agricultural fields. These need to be researched more thoroughly, to understand how effective they are and how they should be designed to work for as many species as possible. Additionally, we can all contribute in our own gardens. That means not eliminating an untidy corner or creating a pollinator garden, which can already make a difference for your own area. Individually, it may have only a small impact, but collectively, it has a significant advantage.
What advice do you have for young biologists starting their careers?
I usually ask as the very first question: Where do they actually want to go? What is the goal in the end? Most of them would like to start a bachelor or master thesis right away, and the specific topic does not matter to them. I always tell them very clearly: “No, it’s not just any topic.” Maybe its okay for a master’s thesis, but what happens afterward? What path does the research set for the students? Unfortunately, few have a long-term plan when they choose this career path. However, having a long-term plan is essential to navigate this challenging career path and establish oneself as a biologist in the professional world.
Which topics from the LIB have you applied in your personal life?
For example, in my garden: About five years ago, we had to remove bamboo, and virtually nothing was left of our garden. Even in a nearby field, it had sent shoots up to 14 meters long. Now we are trying to turn it into a biodiversity oasis. I have planted almost 10,000 flower bulbs there, on an area of about 13 x 10 meters. Can you imagine the quantity? It is my own large-scale eco-experiment. How many species can I gather? How closely packed can everything be while still functioning? Parallel to that, marine aquarium keeping: I have been keeping marine aquariums for about twelve years now. Such a small-scale ecosystem is fascinating.
PD Dr Dennis Rödder has been leading the Herpetology Section at the Museum Koenig since 2011 and supervises students as a lecturer at the University of Bonn. After studying biology at the University of Bonn, he conducted research in biogeography and ecological modelling, first as a postdoctoral researcher at the University of Trier and as an adjunct assistant professor at Utah State University, USA. Since 2010, he has been a professor at the Universidade Estadual de Santa Cruz in Ilhéus, Brazil.