Kategorie: News
Clever males prevail - but is it down to the choice of females or their own cleverness?
A recent study shows that intelligent males of the mosquitofish (Gambusia holbrooki) have a better chance of mating. However, it remains unclear whether this is due to females preferring smarter males or whether the latter are more skilful in asserting themselves.
Evolution of intelligence: more than just survival
For a long time, it was assumed that intelligence in animals arose mainly through natural selection - i.e. through advantages in the search for food or escape from enemies. However, a team of researchers led by Ivan Vinogradov from the Australian National University (ANU) in Canberra believe that there is another driving force: sexual selection. A more efficient brain could not only ensure survival, but also help to find more mates and reproduce more successfully.
Labyrinths and paternity tests
The research team tested male mosquitofish for their cognitive abilities by presenting them with tasks such as traversing mazes or swimming around obstacles. The researchers then observed for two months how successfully the males reproduced. In a controlled environment with plenty of food and no predators, over 2,000 paternity tests were carried out.
The result was clear: males that passed the cognitive tests better sired significantly more offspring than their less intelligent conspecifics.
Favouritism or assertiveness?
But why did the smarter fish mate more successfully? There are three possible explanations:
1. females prefer intelligent males - If they can recognise their cognitive abilities, they could specifically choose the smarter mates.
2. intelligent males are better at ‘courtship behaviour’ - they could be more adept at wooing females.
3. cleverness helps to overcome obstacles - Since female mosquitofish flee from intrusive males, particularly intelligent males could gain an advantage through better navigation.
The researchers emphasise that further studies are needed to find out whether the females actually consciously choose smarter males or whether they are simply more successful at securing mating opportunities.
Relevance for other species
The study suggests that cognitive abilities could play a role in reproductive success in many animal species. For example, female songbirds often favour males with a larger song repertoire - an ability that is associated with better cognitive performance.
Overall, the study provides new insights into the evolution of intelligence and the potential benefits of cognitive abilities beyond mere survival.
For the study, which has just been published in the journal ‘Nature Ecology and Evolution’, the scientists presented male mosquitofish with various tasks, including navigating through labyrinths or swimming around transparent https://dx.doi.org/10.1038/s41559-025-02645-3