Science & Tech · Science & Environment · 57 mins ago
Elephant losses linked to fragmented social groups in Sri Lanka
Researchers tracked 443 female Asian elephants in Sri Lanka's Udawalawe National Park from 2007 to 2018.
As elephants disappeared from the observed population and fewer new ones were identified, groups became smaller and less connected.
About 69% of the females tracked at the start were no longer observed by 2018; this included elephants that died or moved away permanently.
The study found that surviving elephants also lost or changed relationships, not just that there were fewer members.
Weaker ties often connect separate groups, so their loss may reduce the whole community's ability to cope with disruption.
Conservation should track social ties as well as numbers, the researchers said, while noting that a separate population survey would be needed to establish whether the elephant population itself declined.
A 12-year study of 443 female Asian elephants in Sri Lanka found that losses and reduced arrivals were linked to a shift from large, connected communities to smaller, more isolated groups.
Researchers said the social network appears to have passed a threshold as elephants disappeared through death or permanent movement and fewer new individuals were recorded.
About 69% of the females tracked at the study’s start were no longer observed in the population by 2018.
The researchers said social ties among surviving elephants also changed, including among the 59 females observed throughout the study.
They said conservation efforts should monitor social relationships as well as population numbers.
- Who
- Researchers led by Anastasia Madsen and Shermin de Silva at the University of California, San Diego, studied 443 female Asian elephants.
- What
- The study linked accumulated elephant losses and fewer new arrivals to fragmentation of the elephants’ social network.
- When
- The elephants were observed from 2007 to 2018. The study was reported on November 13, 2026.
- Where
- Udawalawe National Park, Sri Lanka.
- Why
- Researchers said losses and reduced arrivals weakened connections between groups and pushed the social network past a threshold.
This story does not have two clearly opposing sides.
Researchers observed wild Asian elephants in Udawalawe National Park over 1,665 days.
The number of elephants disappearing each year rapidly exceeded the number newly recorded.
About 69% of the females tracked at the start were no longer observed in the study population.
The study was reported in the journal Science.
- Study population
- 443 female Asian elephants
- Study period
- 2007–2018
- Observation effort
- 1,665 days
- Records analysed
- 7,744 observations with at least one female
- Tracked females no longer observed by 2018
- About 69%
- Females observed throughout the study
- 59
What people are saying
For many species that live through social relationships, social connection is a matter of sharing the same space and building relationships over a lifetime.
For a community to have resilience against external shocks, it must be able to replace relationships that disappear over time with new relationships.