Science

New publication: Repeatability of signalling traits in the avian dawn chorus

Our newest open access paper on repeatability of avian signalling (song)  traits just came online in the journal Frontiers in Zoology.

Repeatability, consistent individual differences, in signalling behaviour is interesting because it means that those receiving the signal (i.e. listening to the song) could reliably learn something about how the individual singer compares to other singers/competitors.

We repeatedly recorded the dawn song of great tit males throughout the breeding season and show that start time of dawn song and repertoire size are individually repeatable both before and during the egg-laying stage of the mate (when she is fertile). Surprisingly the time a male started singing appeared to be more repeatable (consistent) than repertoire size, despite that the start time was also influenced by variable overnight temperatures. Start time was also more repeatable before than during egg-laying and we suggest that this is related to the behaviour of the (assumingly) intended receivers of the song, the females.

For a subset of the singers, we also explored a potential link between the absolute song trait values, the repeatability of these values and personality. We did not find a link but follow-up studies with a larger sample size, and including additional song traits, will be needed to confirm the true absence of such a link.

Reference
Naguib M, Diehl J, van Oers K, Snijders L (2019). Repeatability of signalling traits in the avian dawn chorus. Frontiers in Zoology 16: 1-11.
https://doi.org/10.1186/s12983-019-0328-7 

Science

New publication: Supporting ape rights: a comment on the role of science

Autumn 2018, friend and colleague Edwin van Leeuwen asked me an intriguing question: if I was interested in co-authoring a comment on an essay about Nonhuman rights? This was a topic we had talked about before and I find very fascinating, timely and relevant. So of course I said yes.

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The central essay and our comment, together with other comments, are part of a special issue on the topic of Great Ape Personhood, published by the ASEBL Journal (Association for the Study of (Ethical Behavior)•(Evolutionary Biology) in Literature; St. Francis College, Brooklyn Heights, N.Y.).  As so nicely explained by the editors (Gregory Tague and Christine Webb) in the introduction of this special issue: with his essay, Professor Thompson tries to bridge the false divide between natural science and humanities. Working from the foundations of philosophy and legal theory [and subsequently discussing important focus points for future research], he tries to reach scientists and their thinking in the battle for great ape personhood.

“Thompson relies on Nonhuman Rights Project attorney Steven Wise, who calls on scientists to awaken the thinking of judges deciding the fate of great apes. Perhaps it’s an unfair analogy, but Thompson attempts to do with primatology what climatologists from several generations tried to do – demonstrate how science is part of and can dramatically affect public policy. Thompson shows how what is empirically rational in science is treated differently in the legal arena, and that difference poses a real problem in the question of granting personhood status and other rights to great apes.”

Several interesting comments were made on the essay, both from philosophers and scientists. Edwin and me commented i.a. by suggesting some alternative ways science could support the quest for Great Ape Rights.

This project was definitely out of my comfort zone. And I see that as a good thing. Thompson’s essay and also the philosophers’ brief, written in support by a group of  philosophers, have given me many new insights about the role of philosophy and science in society. How together, philosophy and science can have some very important things to say about the way we live in this world.

The complete issue can be found here.
And (only) the comment made by Edwin and me, here.

Reference
van Leeuwen E.J.C., Snijders L. (2019) A comment on Thompson “Supporting Ape Rights: Finding the Right Fit Between Science and the Law.” ASEBL Journal 14 (1), 46-48.

 

Science

New preprint: 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.

BioRxiv

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.

Lysanne_field
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.

Reference 
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.

 

Science

New publication: the guppy 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.

Reference
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.

 

Science

New preprint: Guppies on a preprint server

This week I submitted a manuscript to a preprint server for the first time. This is a bit scary because a preprint is not peer-reviewed and so is missing a ‘security check’, something that always makes me feel a bit more at ease when communicating my results [but see: http://thebrainissocool.com/2017/12/19/peer-review-is-not-all-that-is-cracked-up-to-be/%5D. However, I think preprint servers are a great idea, because you don’t have to wait for months before you can finally share your results and show people what you are working on. More importantly, preprint servers provide a way, for those interested, to read your findings without having to pass a pay-wall. A version of your study will thus always stay open-access. So, I put my fears (somewhat) aside and decided to submit my recent manuscript to BioRxiv, before submitting it to a scientific journal.

In the manuscript, we describe a field experiment with wild guppies in Trinidad by which we studied foraging success in the wild. We tested if foraging success in the wild differs consistently between individuals and if these differences can be explained by individual traits such as sex and social type, but also by population traits such as sex-ratio. I think the results are very exciting and also somewhat unexpected. If you would like to find out more, then please read the preprint on BioRxiv.

Guppies_BW_Snijders

 

 

 

 

Conservation, Science

New publication: Linking animal social network theory to conservation

Available for free until September 7, 2017Click this link

Last week, June 22, a for me very important paper was published online in the scientific journal Trends in Ecology and Evolution. With this Opinion paper, me and my co-authors hope to stimulate a closer collaboration between animal social network scientists and conservation practitioners. You can read more about it in our press release below. If you are interested in reading the complete scientific article, but do not have access, please send me a message/email. 

As with humans, most animals prefer to associate with some individuals and not with others. The social structure can influence how a population responds to changes in its environment. Examining social networks is a promising technique for understanding, predicting and – if for the better – manipulating this structure. However, whereas the contribution of behavioural biology to conservation is already well recognized, the usefulness of animal social network analysis as a conservation tool has not yet been addressed. A group of behavioural ecologists led by Lysanne Snijders from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) outlines how the understanding of relationships between animals could be applied by wildlife managers and conservationists to support their work in disease management, breeding programs, reintroductions or relocations, or for controlling problem behaviours – to name just a few.

Animal social network studies examine how the individuals of a population are socially connected, how they interact and associate. Knowledge of the social structure can help to identify the flow of information or the spread of disease, and has potential to be used as an indicator of upcoming population changes. Information of that kind would be less – or not at all – noticeable using methods purely based on population size or the observation of single individuals.

Dr Lysanne Snijders, Post Doctoral Researcher at the Department of Biology and Ecology of Fishes at IGB, describes this approach with the help of Aristotle: “The whole is greater than the sum of its parts. Combined effects of social interactions in wildlife populations do not only have important theoretical but also practical implications. Linking animal social network theory to practice can therefore stimulate the design of new practical conservation tools and generate novel insights into how animal social networks change over time.”

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An example from real wildlife

For many species, it is not just diseases that can spread rapidly. Social information can also be transmitted via various routes within a group, for instance, innovative ways to search for food. In the case of the California sea lion, novel foraging strategies have led to conflict with a fishery conservation scheme. The sea lions had discovered that salmonids migrating upriver became more concentrated at a dam, making them easy prey. Unfortunately, those salmonids were endangered species. A recent study [1] showed that knowledge of the network structure could have helped wildlife managers to detect that at first it was only a few successful individuals who “recruited” the others, and that the selective removal of these information spreaders could have contained the problem. In this case social network analysis could therefore have assisted in protecting the endangered salmonids while culling fewer sea lions.

Snijders also suggests a possible example for how animal social network analysis could be used in conservation work in Europe: “In cases of recently reintroduced group living animals, such as the European bison, social network analyses could give insights into how a population’s long-term persistence might vary with particular behavioural processes within the group. But also into how group and individual movements might be effectively manipulated to avoid human-wildlife conflicts such as entering restricted areas like farm land.”

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Perspectives for implementation

In a field in which funds and time are limited, any newly suggested approach should have a distinct added value. Not every conservation challenge that is linked to a species’ social behaviour will require a social network approach to address it. The scientists also acknowledge that their proposal has to overcome another important hurdle first: before applying the knowledge of social relationships to management practices, it should become feasible and cost-effective to collect the required data in the first place. But with technological options becoming more common and affordable, an animal social network analysis approach could increasingly become an option.

There are several methods out there that have been successfully applied to map wildlife social networks, ranging from sampling individuals at fixed locations, to walking transects, to automatically spatially tracking the animals. Rapid advancements in technology, like proximity loggers and GPS tags, allow for ever smaller animal species to be tracked, while at the same time becoming more affordable. In addition, collaborations between research institutes and conservationists might provide opportunities for sharing the costs or the technology.

A video introduction to animal social networks by Lysanne Snijders >

Article:

Snijders, L., Blumstein, D. T., Stanley C. R., Franks, D. W. (2017): Animal Social Network Theory Can Help Wildlife Conservation. Trends in Ecology and Evolution.

Read this article >

References:

[1] Zachary A. Schakner, Michael G. Buhnerkempe, Mathew J. Tennis, Robert J. Stansell, Bjorn K. van der Leeuw, James O. Lloyd-Smith, Daniel T. Blumstein (2016): Epidemiological models to control the spread of information in marine mammals. Published 14 December 2016. DOI: 10.1098/rspb.2016.2037

 

See original press release here.