Cognitive abilities of female southern pied babblers found to decline with age even as they produce more offspring

Bob Yirka is a research scientist at Phys.org.

As female southern pied babblers grow older, they produce more offspring, even as they lose some of their cognitive abilities. The group tested the birds' cognitive abilities as they aged in the wild while also looking at their reproduction levels.

Black and white birds called pied babblers are found in dry regions of Africa. The researchers wanted to learn more about their cognitive abilities as they get older. They studied and released multiple generations of the birds to determine their cognitive levels. The number of chick produced by each of the females was counted.

The cognitive levels of birds peaked early and then began to decline in females as they got older. The birds produced more and more chick as their cognitive abilities declined.

The tradeoff is suggested by the researchers. It takes a lot of energy to perform cognitive tasks. Reducing the energy requirements of the brain is a way to conserve energy for the birds. This will increase the amount of energy that can be used. Females of the species compete with each other for the right to breed, which uses up a lot of energy but does not take a lot of brain power.

The researchers didn't find any changes in male cognitive abilities as they got older. There is no evidence that birds living in larger groups do better on cognitive tests than birds living in smaller groups. The researchers found that females who had less cognitive decline produced less offspring.

The general cognitive performance declines with female age and is negatively related to fledging success in a wild bird. There is a book titled "PukiWiki" which can be found at 10.1098/rspb.

Journal information: Proceedings of the Royal Society B

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