Aspects of Asian elephants' social life are related to their amount of
stress hormones
Date:
March 17, 2022
Source:
University of Turku
Summary:
An international team of scientists found that sociality is linked
to stress in Asian elephants. For example, loneliness increased
male elephants' level of stress, whereas having babies present
reduced the stress level in female elephants.
FULL STORY ==========================================================================
An international team of scientists found that sociality is linked
to stress in Asian elephants. For example, loneliness increased male
elephants' level of stress, whereas having babies present reduced the
stress level in female elephants.
========================================================================== Social behaviours are common in group-living mammals. It is known that
humans that have friends or other strong social bonds can experience
benefits such as improved health, and increased life span, and a lower
disease risk. These relationships can be attributed to the underlying
effects of lowered circulating glucocorticoid hormones, also called
"stress hormones." But how is social behaviour connected to stress in
other species? Our understanding of its mechanisms in long-lived animals
is largely based on studies in human and non-human primates. Asian
elephants, one of the world's largest terrestrial mammals, have a very intricate social life.
"We investigated four different aspects of the social world of 95 Asian
timber elephants living in their natural habitat in Myanmar. These
elephants work in the timber industry, where they pull and push logs
out of the forest. However, spending much of their time free in their
natural habitat allows the timber elephants to express many of their
natural behaviours, which is often not the case in fully captive systems,
such as zoos. This is a unique research environment and population that
allows us to study many elephants living in their natural environment,
but at the same time have detailed information about their social lives,"
says Dr Martin Seltmann from the Department of Biology at the University
of Turku, the lead author of the study.
Just as humans, lonely elephants seem more stressed Every elephant works together with an elephant handler, and this relationship can last a
lifetime. Therefore, a handler knows very well about his elephant's
behaviours and is able to give detailed information on its social
interactions with other elephants.
From 2014 to 2018, the scientists asked the handlers if their elephants
have friends or if they prefer to stay alone. Furthermore, the team
assessed the size of the elephants work groups as a measure of social
group size, the number of males and females within the work group,
and if there were baby elephants present in the group. In addition,
the researchers also assessed the concentrations of stress hormones from
the elephants' faecal samples.
"We found, that male elephants show higher levels of stress when they
have no friends and when they are in social groups with more males than females. Female elephants show lower levels of stress when babies are
present in the social group. The size of the social group is not related
to levels of stress hormones in males nor females," says Martin Seltmann
and professor Virpi Lummaa, co- author of the study.
The team also expected that females would show signs of stress when
being solitary, because wild elephant females spend their lives with
other female relatives. The researchers think that strong male social
bonds might be more important in the semi-captive setting than in purely
wild elephants. Compared to male elephants, solitary females might still
be able to interact with other individuals without forming strong social
bonds and so the lack of those bonds may not be perceived as a stress.
The findings of this new study highlight the importance of sociality on individual physiological function among elephants, which may have broad implications for the benefits of social interactions among mammals. They
can also help to develop applied methods towards maintaining and improving welfare of captive social animals.
========================================================================== Story Source: Materials provided by University_of_Turku. Note: Content
may be edited for style and length.
========================================================================== Journal Reference:
1. Martin W. Seltmann, John Jackson, Emily Lynch, Janine L. Brown,
Win Htut,
Mirkka Lahdenpera", Virpi Lummaa. Sex-specific links between
the social landscape and faecal glucocorticoid metabolites in
semi-captive Asian elephants. General and Comparative Endocrinology,
2022; 319: 113990 DOI: 10.1016/j.ygcen.2022.113990 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2022/03/220317111900.htm
--- up 2 weeks, 3 days, 10 hours, 51 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)