Asian elephants have a hierarchical social organisation and can be ‘clannish’.
While males separate from the group when they are ten or so years of age, the females move in an organised manner. The closest group consisting of two or three elephants is formed by a female and her calf or a female with her daughter and the daughter’s calf.
A clan of close to a hundred elephants is the apex of groups, made up of families and closely associated individuals..
Elephants maintain good communication among members within a clan, but there is little or no such interaction between members of different clans, a research study shows.
The nearly decade-long study of Asian elephants, led by T.N.C. Vidya of the Jawaharlal Nehru Centre for Advanced Scientific Research, is the only one of its kind in the country.
Scientists have concluded that African elephants are socially organised as family, groups, bond groups and clans, although as much larger-sized groups. But Asian elephants were thought to be different.
Studies by Prithviraj Fernando and others in Sri Lanka came to the conclusion that Asian elephants had only a family group structure but no clans. Another study by Shermin de Silva found more extended associations beyond families.
Know your elephant
Dr. Vidya and her student Nandini who is the first author of their paper that is published in the journal Behavioral Ecology have data on the elephants they have studied running into several notebooks.
They have a page devoted to each elephant out of the 800 or so that they have been observing, giving the name and identification marks of each.
“Impedimenta is one of the largest females we have seen [in Kabini]. Her skull and ears are very large. The top edge of her ears are beginning to fold forward, the left ear more so… she has a large tear (near the side fold) and a small hole on her right ear… About a third of the ear is prominently depigmented,” says Vidya, describing how they identify elephants.
“We usually give them names according to the clan they belong to. However, some names start with a different letter, because it takes time to identify which clan they belong to,“ she adds.
The field work is the most challenging and interesting part of the study: Through the year, the team stays near the forest where they have rented a house, and with help of trackers who are tribal people from the Nagarhole, Bandipur region, they go into the forest and observe associations between elephants.
Help when in trouble
The Kabini reservoir, being a perennial source of water, always sees elephants coming back to it, especially in the dry season. It is thus a good place to study them.
Female elephants may move together in a coordinated manner or close by (within approximately 250 m) or go to drink water and feed together and return. They can also bunch together when threatened.
“So depending on who’s seen with whom and how often, we can construct social networks,” says Dr. Vidya. The bonded group of elephants also help each other during trouble, such as when threatened by humans or if a calf has difficulty moving.
“But these are observed rarely, and we base our studies upon the associations we see regularly,” she clarifies.
Elephants recognise each other mainly using their sense of smell, and it has been observed during a study of African Savannah elephants that they also recognise each other by their calls. It is interesting that such associations are only among elephant members of a clan. Dr. Vidya and collaborators have sometimes observed aggression and dominance when a female elephant encounters a non-clan member.
For Nandini, a doctoral researcher and co-author of the paper, the appeal of going into the forest transcends all the trouble she had to take. “In the early days, there was no power, and she [Nandini] had to pump water even to take a bath in the evenings,” says Dr Vidya.
Applying social networks
The researchers analysed their data using network analysis and what is known as the Louvain method (commonly used in analysing mobile phone networks).
They found a pattern similar to that seen earlier in African elephants. “The main difference was that ecological constraints affect group size. Group sizes are larger in African elephants; if here [in Asian elephants] you see 2-3 elephants feeding together, you would see five together there [African elephants],” explains Dr. Vidya.
Ecological constraints include disturbance due to human interventions and availability of large areas to roam.
Since clans do not mix with each other, any infection usually circulates only within the clan, and knowing the clan members helps in taking preventive measures.
How information moves
This also helps when translocating elephants, as clans must not be broken up. Also, it helps in understanding the way information spreads among the individuals.
If a barricade, for example, is set up by humans and one member of the clan learns to get past it, we can expect that the information will spread from group to group until the whole clan gets to know. Therefore, knowing the group structure can help manage the elephant groups better.
For the team of workers, it is five solid years of data gathering and further analysis that has eventually paid off as the group structure emerges.
But clearly, the work cannot stop with that, and the forest has many more angles, animals and secrets that wait to be studied.
