Nav: Home

Sisters improve chances of reproduction in Asian elephants

July 24, 2019

Researchers at the University of Turku found that the presence of a maternal sister was positively and significantly associated with annual female reproduction in a population of working elephants in Myanmar. In addition, an age-specific effect was found: young females were more sensitive to the presence of sisters and even more likely to reproduce when living near a sister.

- We studied Asian elephants working in the teak industry in Myanmar. The elephants are released to the forest for the evenings and nights and other holiday periods, when they can move around freely, eat and meet other elephants. Our study compared the annual reproductive rate of females living with and without maternal sisters. We found that young females, in particular, are more likely to reproduce in a given year when living near a maternal sister, and this effect was strongest when the sister was 0-5 years younger, says Emily Lynch, lead author of the study.

The authors claim that while the proximate mechanism driving enhanced reproduction may be related to improved health generated by sociality, such age-related benefits suggest other factors may be at play.

- Especially because the parenting experience may be crucial for successfully rearing offspring, young, inexperienced females are at a disadvantage and assistance from relatives may therefore be particularly valuable to young females.

Relationships among females have an important evolutionary basis

- Although there is widespread evidence that individuals prefer relatives over non-relatives as social partners, little is known about the potential benefits associated with living with kin in long-lived, social mammals, Lynch says.

Because elephants are highly social and matrilocal animals, meaning that females remain in their natal group with female relatives throughout their lifetime, it is likely that social relationships provide varying benefits across a female's lifetime.

- Sociality is known to improve both physical and mental health in humans, for example. This study shows that in elephants socialising with female relatives improves the changes of female reproduction. However, the motivation to nurture relationships with female relatives is age-dependent, which, in turn, results in a variety of fitness benefits. Overall, the study suggests that relationships among female kin are of evolutionary importance in long-lived social mammals, Lynch says.

These results build on previous work on this population, in which it was discovered that the presence of a maternal grandmother is associated with improved grand calf survival and increased reproductive output of the daughter, and this effect was particularly strong among young daughters.

- This study is particularly exciting because we were able to access information on elephant reproduction across several generations to effectively examine the evolutionary consequences of female social relationships with kin. Access to such longitudinal data on a long-lived, social mammal is rare and we are now able to have a better grasp of the importance of living with relatives in elephants, Lynch says.
-end-
Emily C. Lynch, Virpi Lummaa, Win Htut and Mirkka Lahdenperä: Evolutionary significance of maternal kinship in a long-lived mammal on the Philosophical Transactions of the Royal Society B: Biological Sciences: The evolution of female-biased kinship in humans and other mammals. https://doi.org/10.1098/rstb.2018.0067

More information: visiting researcher Emily Lynch (emily.lynch@utu.fi), University of Turku

University of Turku

Related Relationships Articles:

Disruptions of salesperson-customer relationships. Is that always bad?
Implications from sales relationship disruptions are intricate and can be revitalizing.
Do open relationships really work?
Open relationships typically describe couples in which the partners have agreed on sexual activity with someone other than their primary romantic partner, while maintaining the couple bond.
The 7 types of sugar daddy relationships
University of Colorado Denver researcher looks inside 48 sugar daddy relationships to better understand the different types of dynamics, break down the typical stereotype(s) and better understand how these relationships work in the United States.
Positive relationships boost self-esteem, and vice versa
Does having close friends boost your self-esteem, or does having high self-esteem influence the quality of your friendships?
Strong family relationships may help with asthma outcomes for children
Positive family relationships might help youth to maintain good asthma management behaviors even in the face of difficult neighborhood conditions, according to a new Northwestern University study.
In romantic relationships, people do indeed have a 'type'
Researchers at the University of Toronto show that people do indeed have a 'type' when it comes to dating, and that despite best intentions to date outside that type -- for example, after a bad relationship -- some will gravitate to similar partners.
Advancing dementia and its effect on care home relationships
New research published today in the journal Dementia by researchers from the University of Chichester focuses on the effects of behavioral change due to dementia in a residential care home setting.
Passion trumps love for sex in relationships
When women distinguish between sex and the relational and emotional aspects of a relationship, this determines how often couples in long-term relationships have sex.
The interplay between relationships, stress, and sleep
A new Personal Relationships study documents how the quality of a person's romantic relationship and the life stress he or she experiences at two key points in early adulthood (at age 23 and 32) are related to sleep quality and quantity in middle adulthood (at age 37).
From asexuality to heteroflexibility: New openness about intimate relationships
The 21st century has ushered in a ''quiet revolution'' in the diversity of intimate relationships, and a leading scholar says the scale and pace of this social transformation warrants a ''reboot'' of relationship studies.
More Relationships News and Relationships Current Events

Top Science Podcasts

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

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#542 Climate Doomsday
Have you heard? Climate change. We did it. And it's bad. It's going to be worse. We are already suffering the effects of it in many ways. How should we TALK about the dangers we are facing, though? Should we get people good and scared? Or give them hope? Or both? Host Bethany Brookshire talks with David Wallace-Wells and Sheril Kirschenbaum to find out. This episode is hosted by Bethany Brookshire, science writer from Science News. Related links: Why Climate Disasters Might Not Boost Public Engagement on Climate Change on The New York Times by Andrew Revkin The other kind...
Now Playing: Radiolab

An Announcement from Radiolab