Science

Research overview 2022

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

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: Don’t forget about your friends

Remember those friends you never see anymore after they got hitched? Not in geese!

In our recently published paper, we show that barnacle geese keep hanging out with there favourite early-life social companions also after they pair up. Females show a break during the breeding season but display their social preferences again in the following winter. Males keep their prefered companions throughout the breeding and wintering season and these companionships were predicted by familiarity and genetic relatedness.

We also show that especially males were aggressive during the breeding season towards both males and females and this possibly hampered their female partners to hang out with their own ‘friends’ during breeding but not winter.

In summary, our study reveals the robustness of social preferences formed early in life, carrying over across pair formation, even after extended temporal disruptions. Our findings thus highlight how the early-life social environment can have life-long consequences on individuals’ social life, even in monogamous species.

Reference
RHJM Kurvers, L Prox, DR Farine, C Jongeling, L Snijders (2019)
Animal Behaviour 164: 25-37
Also as a preprint on BioRxiv 

 

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