Otter eating a fish. Photo: Colourbox.

Poor diets spur risky choices

Monday 05 Oct 20
by Helle Falborg


Centre for Ocean Life

The Centre brings together Danish marine research across disciplines and universities to develop a fundamental understanding and predictive capability of marine ecosystems.

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New meta-analysis study shows that animals' decisions in risky situations are influenced by what they eat.

For an animal in the wild, filling your belly is often about balancing your chances of getting food, with the danger of becoming food. 

If animals experience a nutritionally poor diet, they are more likely to make risky choices. This is the main finding of a large meta-analysis of risk-taking behaviour in animals, and what causes an individual to be particularly risk prone or risk averse. 

“Our findings show that an animal’s decisions in risky situations are influenced by their diet, where individual’s with a poorer diet are (on average) more likely to make risky choices”, says the study’s first author, Postdoc Nicholas Patrick Moran, DTU Aqua.

Data from studies of more than 100 species

The study analysed data from 128 experimental studies, covering over 100 species of animals of many different sizes and habitats such as squirrels, tadpoles, fish, lizards and capuchins. 

 “We were looking for studies that tested how willing animals were to take risks in a wide range of contexts, like how they explored unfamiliar environments, responded to predators, etc., following periods of good or bad nutrition,” says Nicholas Patrick Moran.

Pooled together, the results showed, that a nutritionally poor food supply causes an increase of about 26% in an animal’s willingness to take risks compared to animals who have experienced a better diet. The study was conducted in cooperation with researchers from Bielefeld University, and the Friedrich Schiller University Jena, Germany, and it is published in Biological Reviews. 

 ‘We did not expect to find such a clear effect, because each species has different ecological factors influencing their behaviour, and there are so many different contexts where risk-taking behaviour is measured. That the effect appears to apply so broadly, so really highlights the significance of our diet to how we act”, says Nicholas Patrick Moran, and adds: 

“Animals weigh up risks when making decisions throughout their lives, and just like with people, some are more prone to risky behaviour and some are more cautious. Understanding how diet and nutrition influence these patterns in behaviour gives us a greater understanding of how animals behave in nature, and maybe us too.”

Dr. Nicholas Moran is a MSCA Research Fellow at the Centre for Ocean Life at  DTU Aqua. This work was carried out in connection with the DFG Collaborative Research Centre, SFB TRR 212 (NC3), with Bielefeld University and Friedrich Schiller University Jena in Germany.

Read the scientific article in Biological Reviews:
Poor nutritional condition promotes high‐risk behaviours: a systematic review and meta‐analysis
13 MAY 2021