Communication, Science

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

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.

Three female Trinidadian guppies

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.’

Guppies eating a berry they just found

Reference

Snijders, L., Krause, S., Tump, A.N. et al. Causal evidence for the adaptive benefits of social foraging in the wild. Commun Biol 4, 94 (2021). https://doi.org/10.1038/s42003-020-01597-7

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 

 

Conservation, Science

New publication: Elephant rewilding

Recently, I received the honourable request to comment on an article about the rewilding of captive Asian elephants. It’s not a topic I am very familiar with, so writing this commentary actually became a wonderful learning experience for me.

Several strong commentaries from cultural, ethical and psychological perspectives were already written. Here I tried to also add a relevant ecological & evolutionary perspective, focussing on the behavioural ecology of Asian elephants and their functional role in the ecosystem.

Abstract: Baker & Winkler make a thought-provoking contribution to the discussion of what role captive animals could play in nature conservation and how we could get there through rewilding. There certainly is potential for captive Asian elephants, Elephas maximus, to become targets of conservation efforts, but there are also many questions: (1) How much do (behavioural) traits of captive-origin animals differ from their free conspecifics? (2) What predicts the likelihood and strength of social reintegration of captive animals into free populations? (3) How much of an Asian elephant’s functional role in the environment can captive animals still fulfil and how may this influence the evolutionary dynamics of Asian elephant populations? These questions are challenging, but also an opportunity to gain crucial knowledge and insight into the elephant’s ecological role, as well as our own.

If you are interested in reading the complete commentary (approx. 1000 words) see here.

Reference
Snijders L (2020) Ecological and evolutionary dynamics of elephant rewilding. Animal Sentience 28(6): 1-4.

Communication, Conservation, Science

The case of cats and conservation

Tanja and I explored another conservation conflict on our Medium blog.

When a potential response to an urgent situation is either unlikely to work at all or unlikely to address the bulk of the problem, under what conditions should we try it anyway?

In this exploration, we wanted to share perspectives on the controversial case of cats in Australia, also by some called the ‘war against cats’. In 2015, the Australian Government launched the threatened species strategy to kill 2 Mio cats in Australia by 2020 with the aim to protect endemic wildlife. Four years after the strategy was launched, Australian researchers in Conservation Letters questioned the motives (conservation or politically driven) and the science behind the decision.

Just how much of a sensitive topic this particular case study is, we noticed by how difficult it was for us to find contributors. Luckily we found two experts from Moral Philosophy that shared their insight with us:

Carlos Gray Santana is an Assistant Professor in Philosophy at the University of Utah. Dr Santana’s uses ethics to shed light on complicated issues such as the environment and human cognition. William S. Lynn is a Research Scientist in the George Perkins Marsh Institute at Clark University. The focus of Bill’s work is the ethics and politics of animal protection and sustainability.

For optional guidance, we asked the experts the following questions:

  • Why is the matter of cats and wildlife so controversial?
  • Why do you think politicians focus on culling cats rather than on habitat loss (as suggested in Doherty et al. 2019) and could open discussions be fostered to move beyond culling?
  • How do you think the public would respond when culling of cats turns out not to be effective in halting endemic species decline?

Curious about what they had to say? Read our blog post here.
And you can also follow us on Twitter!

Photo credits: Pacto Visual on Unsplash