Science – Dr Lysanne Snijders

This week the moment I was looking forward to for some time is finally there: the MOOC on Animal Behaviour in Conservation is running on Edx!

After over a year of preparation and with the help of many people, we (James Savage, Marc Naguib and I) were able to create a free online course that helps participants apply the animal behaviour perspective on conservation challenges. Specifically, we highlight three challenges: rapid environmental change, human-wildlife conflict and wildlife reintroductions.

In this MOOC, we explore key concepts from animal behaviour and apply them to practical wildlife conservation issues. Such behaviour-sensitive management has led to successful conservation interventions:

A wind farm with technology warning for migrating birds decreased soaring bird mortality to zero with a shutdown period of only 0.2–1.2%.
A livestock grazing strategy avoiding cheetah communication hubs reduced livestock losses with 86%.
A mammal translocation program taking neighbour relations into account led to 24 times more offspring for translocated individuals.

Through informative knowledge clips, case studies, interviews, and practical assignments, participants learn how to use animal behaviour in conservation to effectively monitor threats, increase their understanding of the diverse responses to environmental change, and design innovative interventions.

To find out more or enroll, click here to go to the Edx website.

Photo credits: Marc Naguib

Science

Research overview 2022

November 17, 2022 Lysanne Snijders

It has been a bit quiet on my website, but this is not because nothing was happening. It has been a busy year with research, service, grant writing and education (more on that last point in another post). In this post, I want to give a short overview of some of the research I have been doing this year.

Publications

Smith B.P., Snijders L., Tobajas J., Whitehouse-Tedd K., van Bommel L., Pitcher B., St. Clair C.C., Appleby R.G., Jordan N., Greggor A.L. (in press). ‘Management techniques for deterring and repelling wildlife’ in Smith B.P., Waudby H., Alberthsen C. (eds) Ethical wildlife research in Australia. CSIRO Publishing, Melbourne, Australia. ISBN: 9781486313440

This book chapter provides general operating procedures (GOPs) and guidelines for a variety of non-lethal techniques, which seek to interrupt, reduce or modify the behaviour of wildlife to decrease the occurrence of ‘unwanted’ or ‘undesirable’ behaviours.

Naguib M., Titulaer M., Waas J.R., van Oers K. Sprau P., Snijders L. (2022). Prior territorial responses and home range size predict territory defense in radio-tagged great tits. Behavioral Ecology and Sociobiology 76: 35. DOI: 10.1007/s00265-022-03143-3

The extent to which responses of a resident to a territorial intrusion predict its future responses is not well understood. In this study, we used wild great tits (Parus major) as a model species and revealed that home-range and spatial response, but not vocal response, predict future responses to simulated territory intrusions.

Snijders L., Krause S., Tump A.N., Breuker M, Ramnarine I.W., Kurvers R.H.J.M., Krause J. (2022). Ephemeral Resource Availability Makes Wild Guppies More Social. BioRXiv. DOI: 10.1101/2022.05.20.492799

Resource availability and sociality are tightly coupled. Sociality facilitates resource access in a wide range of animal species. Simultaneously, resource availability may change sociality. We discovered that the presence of temporarily available food patches increases the sociality of wild guppies two-fold, even when the food was no longer present.

Kurvers R.H.J.M, & Snijders L. (2022). Group Size: The balance of the sexes. Elife, 11, e83254. DOI: 10.7554/eLife.83254

In this brief commentary, Ralf Kurvers and I respond to a recently published study on cooperation and competition as drivers of group size variation in ostriches. We highlight the relevance of this research and suggest interesting follow-up questions for future research.

Upcoming research highlights

Principal Investigator:

Exploration behaviour and partial migration in noctule bats (first draft finished)

Effectiveness of animal conditioning in mitigating human-wildlife conflict (data extraction stage)

Population differences in social foraging dynamics of wild guppies (data analysis stage)

Co-author:

Spatiotemporal responses of wild ungulates to hunting in a fenced multi-use area (first draft finished)

Behavioural indicators of bird flue in waterfowl (analysis finished)

Ecoacoustics: a biodiversity yardstick as a facilitating tool for nature-positive food production (funded)

Wildlife going to town: facilitating shared landscapes for humans and wildlife (funded – start 2023)

I look forward to sharing more details about these studies once they come out!

Conservation, Science

New publication: Conditioned taste aversion in human-wildlife conflicts

October 14, 2021October 14, 2021 Lysanne Snijders

On the 13th of October, our review on an animal behaviour-based conservation intervention appeared online in Frontiers in Conservation Science. In this review, we visually, quantitatively and narratively synthesize the existing (English) evidence-base on the effectiveness of conditioned taste aversion (CTA) in human-wildlife conflict contexts. By evaluating this literature in the view of learning principles we were able to compose a decision-support table to guide future applications of this technique. Working with all coauthors for the first time, this project has taught me a lot about learning theory and the state-of-the-art application of it in conservation.

Modern wildlife management has dual mandates to reduce human-wildlife conflict (HWC) for burgeoning populations of people while supporting conservation of biodiversity and the ecosystem functions it affords. These opposing goals can sometimes be achieved with non-lethal intervention tools that promote coexistence between people and wildlife.

CTA has been applied to a wide range of animal taxa (57 (sub)species, 26 families and 11 orders)

One such tool is conditioned taste aversion (CTA), the application of an evolutionary relevant learning paradigm in which an animal associates a transitory illness to the taste, odor or other characteristic of a particular food item, resulting in a long-term change in its perception of palatability. Despite extensive support for the power of CTA in laboratory studies, field studies have exhibited mixed results, which erodes manager confidence in using this tool.

Application of CTA in various human-wildlife conflict categories across time

In this paper, we review the literature on CTA in the context of wildlife conservation and management and discuss how success could be increased with more use of learning theory related to CTA, particularly selective association, stimulus salience, stimulus generalization, and extinction of behavior. We apply learning theory to the chronological stages of CTA application in the field and illustrate them by synthesizing and reviewing past applications of CTA in HWC situations. Specifically, we discuss (1) when CTA is suitable, (2) how aversion can be most effectively (and safely) established, (3) how generalization of aversion from treated to untreated food can be stimulated and (4) how extinction of aversion can be avoided.

For each question, we offer specific implementation suggestions and methods for achieving them, which we summarize in a decision-support table that might be used by managers to guide their use of CTA across a range of contexts. Additionally, we highlight promising ideas that may further improve the effectiveness of CTA field applications in the future. With this review, we aspire to demonstrate the diverse past applications of CTA as a non-lethal tool in wildlife management and conservation and facilitate greater application and efficacy in the future.

Reference
Snijders, L., Thierij, N. M., Appleby, R., St Clair, C. C., & Tobajas, J. (2021) Conditioned taste aversion as a tool for mitigating human-wildlife conflicts. Frontiers in Conservation Science, 72: 744704

Science

New publication: Acoustic exploration is a repeatable behavioral response in migratory bats

April 14, 2021April 15, 2021 Lysanne Snijders

On the 14th of April, my first bat paper came online in the journal Scientific Reports. In this paper, led by the talented Theresa Schabacker, we studied how bats explore novel roost-like environments using a newly developed maze-type testing arena. We here show that individuals differ in how they use echolocation to explore, with some bats consistently under-sampling a novel environment while others over sample.

Through exploration animals gain vital information about the availability of resources, the distribution of conspecifics, and the presence of predators. It also helps them to pick up changes in the environment quicker. Studies on how animals explore novel environments are usually conducted by measuring spatial movements. Yet, when exploring, not only where an animal goes is relevant, but also, or even especially, the information it acquires. Birds get new information primarily by using vision, which is challenging to measure. Bats, on the other hand, primarily use echolocation, which we can measure!

Schematic drawing of the maze used during behavioral assay. A) Opaque start tube where bats were placed at the start of each assay B) Barriers closing entrance to maze C) Gates connecting single chambers D) Position of microphone. ©Rebecca Scheibke

We developed a maze-like test arena in which tree-roosting bats could explore small chambers that were connected through ports. This arena is designed so it can easily be brought to the field, in this case the Pape Ornithological Station in Latvia, and so the bats do not need to be transported away from their habitat. Using a night-vision camera and a sensitive microphone we recorded the spatial and acoustic behavior of migratory Nathusius’ pipistrelles (Pipistrellus nathusii) for two minutes after they voluntarily entered the maze (some never entered). We did this twice for over 50 individual bats and discovered that not only the echolocation behavior and the number of chambers they visited was strongly correlated (more chambers meant more echo calls), individuals also consistently differed in how many calls they made per chamber. Some were just more thorough in sampling these new chambers than others. This sampling behavior was also correlated to another seemingly explorative behavior: the number of times they took peeks (but did not enter) other chambers.

Nathusius pipistrelle. Photo credit: Evgeniy Yakhontov, Creative Commons Attribution-Share Alike 3.0 Unported — Nathusius pipistrelle. These little guys are excellent climbers and crawlers, which helps them in finding suitable new roosts, often in trees and bat boxes. Photo credit: Evgeniy Yakhontov, Creative Commons Attribution-Share Alike 3.0 Unported

These bats remind me of how people differ when going through a museum. Some go and look at every painting in a room while others are satisfied with just a few highlights. Bats are not so different as it turns out. Of course, this raises tons of new questions, like: do more thorough exploring bats indeed detect changes in their environment sooner? Does this bring them a fitness-benefit? Or is it actually very costly to echo-locate this much? And does a quickly changing environment select for more thoroughly exploring bats?

Still so much to explore!

Experimental set-up of maze-type arena for testing exploration behavior in tree-roosting bats. Photo credit: Lysanne Snijders

Reference

Schabacker T, Lindecke O, Rizzi S, Marggraf L, Pētersons G, Voigt CC, Snijders L (2021). In situ novel environment assay reveals acoustic exploration as a repeatable behavioral response in migratory bats. Scientific Reports: Online.

Communication, Science

New publication: Causal evidence for the adaptive benefits of social foraging in the wild

January 23, 2021 Lysanne Snijders

On 20-01-2021 the latest fruit of our Trinidadian guppy research project came online in the Open Access journal Communications Biology. With this experimental field study, we provide rare causal evidence for the adaptive benefits of social foraging in the wild. For both sexes!

For the complete story, check out the paper here.
For the popular science summary, check below (Dutch version here)

Guppies with friends eat more

Guppies that socialise with more conspecifics get more food. This applies to both males and females, despite the common assumption that males are not very social. This is revealed through a unique field study conducted by Wageningen University & Research in Trinidad in collaboration with Leibniz-Institute of Freshwater Ecology and Inland Fisheries.

‘Much research has already been done under lab conditions on the impact of group size on animals’, says Lysanne Snijders. ‘Still, you never know whether the results such studies show, apply equally in nature’. Moreover, in the wild, other factors such as predators’ presence also influence animals’ social behaviour.

Benefits of social behaviour

As far as we know, this is the first time a causal relationship was found between the number of animals of the same vertebrate species and it’s benefits to individuals. In Trinidad, Snijders and her colleagues were able to get a close look at the influence of size and composition of groups under natural circumstances by distributing the guppies over different pools. The behaviour of the fish in different group sizes was extensively analysed and recorded.

Snijders and her team showed that guppies living in larger groups were often more successful at obtaining food. From an evolutionary perspective this is interesting: apparently, an increased food intake is a direct benefit of being social in the wild (as is protection from predators), and may thus partly explain why we often see guppies engage in social associations.

Our fieldwork site in the Trinidad rainforest

Males

Moreover, the study, published in Communication Biology, shows that males and females alike benefit from larger groups. This is remarkable, as females are generally perceived as more social.

Snijders: ‘In the vast majority of guppy research, the study is limited to females because males are thought to be predominantly occupied with mating opportunities. This study, under natural circumstances, clearly shows that males also benefit from social behaviour and that this advantage is not solely restricted to them obtaining females. Assumptions about a lower level of sociability do thus not necessarily translate into fewer social benefits.’