Nav: Home

Bravery may cost fish their lives

May 04, 2017

Fish that show bravery often become prey themselves, whereas shyer individuals survive to a greater extent. Researchers at Lund University in Sweden have now successfully established a connection between bold personalities and the risk of being killed by a predator in the wild.

The researchers marked common roaches, a widespread freshwater fish, and studied their personalities. After investigating which individuals then became food for cormorants, the biologists at Lund University were able to show that the bravest fish run twice the risk of being eaten compared to the shyest individuals.

Common roaches, just like human beings, are individuals with different personalities and traits. One of these is courage -- and not all common roaches are equally bold.

For a long time, researchers have assumed that the inclination to expose oneself to risks is a compromise between the actual risk itself and any associated consequences on the one hand, and the potential reward on the other. Boldness and the willingness to take major risks are thus a strategy which can lead to something really tasty to eat or a partner with whom to mate. But it can also end badly.

Until recently, there have only been a few research findings from wild populations to support this assumption. That is, until now, when the biologists studied personalities among common roaches in Krankesjön lake in southern Sweden.

Captured common roaches were taken to a lab and placed in a dark concealed area. Then, the researchers measured how long it took each fish to swim out of the concealed area. The bolder the individual, the less time it took. Each common roach was subsequently implanted with a microchip and released in Krankesjön lake.

At the lake, plenty of fish-eating cormorants ate the tagged common roaches. The birds then regurgitated fully functioning microchips on the small island where they rest between searches for food. By using a portable reader, the researchers were able to identify which common roaches had fallen victim to the cormorants -- the bolder or the shyer individuals.

Relating the behaviour of a certain individual to the risk of being killed by a predator is a major challenge. A number of previous studies have instead focused on how morphological characteristics (appearance and shape) are linked to the risk of being eaten by a predator.

"Our study is unique in that we focus on an important behaviour and not morphology, but also because we allow the interplay between predator and prey to take place in their natural habitat, their home lake", says Kaj Hulthén, one of the researchers behind the study.
-end-


Lund University

Related Behaviour Articles:

World-first studies reveal occurrence of 'chew and spit' eating behaviour
A landmark study into the prevalence of the disordered eating behaviour known as 'chew and spit' has revealed concerning levels of such episodes among teenagers.
Collective behavior 480 million years ago
Researchers studied fossilized Moroccan Ampyx trilobites, which lived 480 million years ago and showed that the trilobites had probably been buried in their positions -- all oriented in the same direction.
New method improves measurement of animal behaviour using deep learning
Konstanz researchers develop deep learning toolkit for high-speed measurement of body posture in animals.
Impulsive behaviour linked to sleep and screen time, CHEO study finds
A paper published today in Pediatrics suggests that children and youth who do not sleep enough and use screens more than recommended are more likely to act impulsively and make poorer decisions.
Prenatal parental stress linked to behaviour problems in toddlers
Expectant parents' emotional struggles predict emotional and behavioural problems in 2-year-olds, new research shows.
Transformer cells: Shaping cellular 'behaviour'
Scientists from the Sechenov University, conjointly with their fellow Chinese and American researchers, have examined the latest advances in the use of skeletal muscle progenitor cells, specifying the core challenges inherent to the applicability of MPCs in cell therapy, and outlining the most promising breakthrough technologies.
Heritable behavioral differences between cat breeds
Cat breeds differ from each other in behavior with regard to activity, aggressiveness, shyness, sociability and stereotypical behavior.
Human impact on the activities and social behaviour of urban capuchin monkeys
To better understand how primates adapt to the increasing presence of humans, researchers monitored a group of 17 capuchin monkeys for a year and a half.
Parental behaviour affects the involvement of children in cyberbullying
The information analysed by this group of researchers came to another conclusion: when parenting practices are not very suitable, it seems that the probability increases that the children might be victimised or involved in the double role of aggressor/victim, while in the case of girls, when they are treated in this way, they tend to be cyber-aggressors.
A scientific study reveals the enigmas on social behaviour of western lowland gorillas
A new study reveals one of the enigmas related to the social behaviour of the western lowland gorilla (Gorilla gorilla gorilla) in the heart of the African equatorial rainforest. hese primates show a dynamic social structure -- individuals change frequently between families -- with a high degree of tolerance and peaceful coexistence among the members.
More Behaviour News and Behaviour Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab