More guppies on the preprint server

After my good experience with the first preprint publication, I recently uploaded my second preprint on the BioRxiv server. I am really excited to share these cool new findings, especially since this study almost did not happen.


Fieldwork is always full of surprises, including flash floods (2018) and cars being stolen (2016). The year of this study (2017), we got stuck on Curacao because our airline was grounded (due to airplane safety concerns, we found out later). Curacao is a great island to spend some time, but it just lacked our favourite little fish: guppies. Luckily, we were able to get new flights and make it to Trinidad a couple of days later.

I love working with guppies, because they allow us to answer some very interesting questions about social living. Guppies live in rainforest streams and in the dry season they often end up in separate pools. These little fish thus naturally experience a variety of physical environments (pools) and social environments (the other fish in the pool). We take advantage of this natural system by trans-locating individual fish to different pools with different social compositions. Most animals would try to go back to their original environment, but for guppies experiencing new physical and social surroundings is just part of their ecology. That we can experimentally control their (social) environment is important, because it allows us to go beyond correlation and ask questions about causality, e.g. how does social composition influence individual foraging success?

To answer this question, we introduced individually marked wild guppies in single sex (male or female) or 50:50 sex compositions, to different pools and studied individuals’ social behavior and their ability to locate novel (experimentally introduced) food patches.

Me, being fascinated by guppies

Male guppies found fewer novel food patches in the absence of female guppies, while female patch discovery did not differ between single-sex or mixed compositions. We argue that these results were driven by sex-dependent mechanisms of social association: males reduced sociality when females were absent, while less social individuals found fewer patches. Females were, however, similarly social with or without males. Finally, males, but not females, preferred to join females over males at food patches.

Our study’s take-home message: for a more thorough understanding of social evolution, it is important to consider how individual (e.g. sex) and (sub)population-level traits (e.g. sex composition) interact in shaping the adaptive value of social living in the wild.

Maybe also: don’t fly with Insel Air.

Snijders L, Kurvers R.H.J.M, Krause S., Tump A.N., Ramnarine I.W., Krause J. (2018) Females facilitate male patch discovery in a wild fish population. BioRxiv.



New guppy publication: the background stories

I am very proud to share my latest publication in Nature Ecology Evolution (NEE). It is the first paper from my ‘guppy’ postdoc at the Leibniz-IGB. It is also the first time (I think) that a manuscript of mine got accepted by the first journal I sent it to, which is also nice for a change :-). Guppies were also the topic of my final year’s highschool science project o, which makes this publication extra special for me. Fish are amazing creatures and I am happy I get to share their stories.

Next to our scientific article, I wrote two background stories:

Social individuals find more food – IGB-website
Guppy_colour_SnijdersHow do you find food when the food is never exactly present at the same place or time? Wild guppies living in the rainforest of Trinidad are faced with this vital question every day. Looking at guppies, it turns out that there are a few keys to finding unpredictable food: being social and surrounding yourself with females. Read more

Being consistent in a dynamic environment: a guppy story – NEE-website
Sometimes things happen that can give you a whole new appreciation of the study system you are working with. For me this thing happened this year. Read more

If you are more of a visual person, I also made a little Youtube video.

The research article can be viewed for free, but please contact me, for example via ResearchGate, if you would like to have the PDF.

Snijders L, Kurvers RHJM, Krause S, Ramnarine IW, Krause J (2018). Individual- and population-level drivers of consistent foraging success across environments. Nature Ecology and Evolution.



New job!

March 2017, I will start as a postdoc with the Leibniz Institute of Freshwater Ecology and Inland Fisheries, also known as IGB-Berlin. Supported by a 12-month IGB-fellowship, I will study the social network dynamics of guppies, both in the wild (Trinidad!) and in the lab.

I will keep you up to date with my experiences and findings in the field (and the lab) via my website. As a teaser, some pictures from last year’s field work in this beautiful country:

Want to know a bit more about the institute I will spend the next 12 months?

The Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) is a creative, lively and diverse place for conducting research and teaching. Scientists from a whole range of disciplines work under one roof at our Berlin and Neuglobsow sites. Hydrologists, chemists, physicists, microbiologists, limnologists, fish ecologists and fisheries biologists from all over the world investigate the fundamental processes governing rivers, lakes and wetlands, and join forces to develop measures conductive to sustainable water management. In the process, we think beyond individual disciplines and spatial boundaries. After all, it will only be possible to develop solutions to the major challenges of the future by taking an integrative research approach.