Older blue tits dominate over younger ones in reproduction
A new study published by a team at the Max Planck Institute for Biological Intelligence has interesting findings about blue tit reproduction. The study focused on how a bird’s age affects its chance of fathering chicks outside its social pair (extra-pair paternity).
Blue tits are small songbirds found in Europe and Asia. While they typically form pairs for breeding, some males also mate with females outside their pair. This can lead to chicks being fathered by a different male than the one raising them, known as extra-pair paternity.
The researchers looked at the breeding success of younger male blue tits (“yearlings”) in two situations. In one group, older males were present, while in the other, they were removed. The found that yearling males had a much higher chance of fathering chicks outside their pair when older males weren’t around. This suggests that older males may have some kind of advantage over younger ones. They might be more dominant or compete more effectively for mates, making it harder for younger males to find extra-pair mating opportunities.
These findings are important because they help us understand how age structure in animal populations can influence reproduction. The study also raises questions about cooperative breeding systems, where multiple birds help raise young. Perhaps in these groups, younger males can focus more on finding extra mates because others help care for the chicks. More research is needed to fully understand these connections. However, this study provides valuable insights into blue tit breeding behaviour and how age can play a role in a male’s mating success.
