Studying reproduction in animal populations can be difficult and can have mixed findings. Previous research has shown that inherited genetics are important, while others say having a helper or social friend is a benefit.
New Research In Both Areas
A new study is the first of it's kind to research both areas: genetics and social effects.
The results show that both areas are important for animal reproduction. The study was based on 25 years of field observation led by Dr Bill Sherwin of University of New South Wales (UNSW) School of Biological, Earth and Environmental Sciences. He notes:
Surprisingly, the genetic and social effects on reproduction have never been studied together in natural populations...[but] we could do so by using the long-term observations about which females were associating with each other, and putting that together with what we knew about their genetic relationships.
Why Do Relationships Help?
It is still unclear why female dolphins need help to be successful mothers. One theory is that dolphins can be attacked by sharks so protection from other females may help with reproduction.
Social Associations And Friends
Researchers found that a female's success at reproduction was boosted either by having a relative with a history of successful reproduction or by associating with other females with a history of successful reproduction. "Having successful sisters, aunts and mothers around certainly boosts a female's calving success. But the benefits of social associates were more important for female pairs who were less genetically related," said Sherwin.
- Successful Mothers Get Help from Their Friends, Dolphin Study Finds (Science Daily)
- Social and genetic interactions drive fitness variation in a free-living dolphin population (PNAS)