Studies have identified that 18 elephant routes exist between Tamil Nadu and Kerala
| Photo Credit: ANI

The elephant population in India stands at 25,000 to 30,000, earning the species an “endangered” status. Their range today is estimated to be only 3.5% of what it was earlier, being restricted to the Himalayan foothills, the northeast, some forests of central India, and hilly forests of Western and Eastern Ghats.

Of particular concern is the fragmentation of their habitat: small, forested areas providing sustenance for elephants, interspersed with human-developed landscapes. Fragmentation can also lead to restricted breeding choices. This creates genetic bottlenecks and, in the long term, a reduction in the fitness of the herds.

Frequent movement of elephants between their habitable zones brings them into contact with roads and railway lines. The range of a female elephant covers about 500 sq. km, and traveling over so much distance in the age of fragmented habitats makes a road or railway crossing very likely.

Fortunately, not all elephant tracks pose these hazards. The elephants of Bandipur, Mudumalai and Wayanad go on a seasonal summer migration. They head for the Kabini Dam backwaters for both water and green grass. Studies have identified that 18 elephant routes exist between Tamil Nadu and Kerala.

Wildlife corridors are a solution — these managed lands allow for migration with minimal human contact. One good example is the Motichur-Chilla corridor in Uttarakhand, which allows the flow of elephant genes between the Corbett and the Rajaji National Parks. However, there is always the risk of conflict with humans, with elephants occasionally feasting on crops, or crossing roads and railway tracks.

Train speed

In a Canadian study attempting to mitigate animal-train collisions, train-triggered warning systems comprising flashing lights and bell sounds were installed at various locations along the tracks. These signals activated 30 seconds before train arrival, were aimed at conditioning animals to associate the warnings with approaching trains.

Cameras recorded animal responses to trains with and without warning signals, on both straight and curved tracks. Large animals, such as elks (from the deer family) and grizzly bears left the tracks about 10 seconds before the train arrived when there was no warning system, and about 17 seconds before the train arrived when warning bells and lights were deployed (Transportation Research, vol 87, 2020).

The response to an approaching train is less in curved sections of the track, probably due to reduced visibility. In such places, sound is used by animals. However, the ability to hear an approaching train is significantly influenced by factors such as high train speed.

AI methods

When should an engine driver reduce speed when passing through forests that are elephant habitats? The Indian Railways has a vast network of optical fiber cables. These support telecommunications and carry data, and importantly transmit signals for train control. In a recently introduced system called Gajraj, geophonic sensors on these OFC lines are tuned to pick up the vibrations of the deep and resonant footsteps of passing elephants.

This AI-based intrusion detection system analyses data from the sensors, extracting relevant features such as frequency components and duration of vibration. If elephant-specific vibrations are detected, an alert is promptly sent to locomotive drivers in the area, and train speeds are reduced. The system is now operational in the Alipurduar area of north West Bengal, which has been the site of several tragic accidents in the past.

(The article was written in collaboration with Sushil Chandani, who works in molecular modelling)

In this undated photo, an African elephant family comforts a calf in Samburu National Reserve, Kenya. A new study in Nature Ecology & Evolution demonstrates that elephants respond to individual names, one of the few animal species known to do so.
| Photo Credit: AP

Over the years, researchers who study elephants have noticed an intriguing phenomenon. Sometimes when an elephant makes a vocalization to a group of other elephants, all of them respond. But sometimes when that same elephant makes a similar call to the group, only a single individual responds.

Could it be that elephants address each other by the equivalent of a name? A new study involving wild African savannah elephants in Kenya lends support to this idea.

The researchers analyzed vocalizations – mostly rumbles generated by elephants using their vocal cords, similar to how people speak – made by more than 100 elephants in Amboseli National Park and Samburu National Reserve.

Using a machine-learning model, the researchers identified what appeared to be a name-like component in these calls identifying a specific elephant as the intended addressee. The researchers then played audio for 17 elephants to test how they would respond to a call apparently addressed to them as well as to a call apparently addressed to some other elephant.

The elephants responded more strongly on average to calls apparently addressed to them. When they heard such a call, they tended to behave more enthusiastically, walk toward the audio source and make more vocalizations than when they heard one apparently meant for someone else.

The study’s findings indicate that elephants “address one another with something like a name,” according to behavioral ecologist Mickey Pardo of Cornell University and formerly of Colorado State University, lead author of the study published on Monday in the journal Nature Ecology & Evolution.

“Certainly, in order to address one another in this way, elephants must learn to associate particular sounds with particular individuals and then use those sounds to get the attention of the individual in question, which requires sophisticated learning ability and understanding of social relationships,” Pardo said.

“The fact that elephants address one another as individuals highlights the importance of social bonds – and specifically, maintaining many different social bonds – for these animals,” Pardo added.

Elephants, Earth’s largest land animals, are highly intelligent, known to have keen memory and problem-solving skills and sophisticated communication. Previous research has shown that they engage in complicated behavior – visual, acoustic and tactile gestures – when greeting each other.

Why would an elephant call to another elephant by “name”?

“We don’t know exhaustively, but from our analysis it appears commonly during contact calls where an elephant calls to another individual – often by name,” said Colorado State University conservation biologist and study co-author George Wittemyer, chair of the scientific board of the conservation group Save the Elephants.

“It was also common among a mother’s rumbles to her calves, often to calm them down or check in with them. We thought we would find it in greeting ceremonies, but it was less common in those types of vocalizations,” Wittemyer added.

Using individual-specific vocal labels – names – is rare, but not unprecedented, in the animal kingdom. Dolphins and parrots have been shown to do this, too. But when they do it, they just imitate vocalizations made by the other animal. In elephants, the vocal labels are not simply imitating the sounds made by the addressee.

“Instead, their names seem to be arbitrary, like human names,” Pardo said. “Addressing individuals with arbitrary names likely requires a capacity for some degree of abstract thought.”

“I think this work highlights how intelligent and interesting elephants are, and I hope that engenders greater interest in their conservation and protection,” Wittemyer added.

Might people one day be able to “talk” with elephants?

“That would be fantastic, but we are a long way off from that,” Wittemyer said. “We still don’t know the syntax or basic elements by which elephant vocalizations encode information. We need to figure that out before we can make deeper progress on understanding them.”

The male savannah elephant Doma and the male savannah elephant Mainos engage in greeting behaviour at Jafuta Reserve in Zimbabwe, in this undated handout picture.
| Photo Credit: Reuters

People greet each other in a variety of ways. They might say “hello,” “guten tag,” “hola,” “konnichiwa” or “g’day.” They might shake hands, bump fists, make a fist-and-palm gesture or press their hands together with a gentle head bow. They might kiss on the cheek or hand. And they might give a nice big hug.

For elephants, greetings appear to be a similarly complex affair. A study based on observations of African savannah elephants in the Jafuta Reserve in Zimbabwe provides new insight into the visual, acoustic and tactile gestures they employ in greetings, including how greetings differ depending on factors such as their sex and whether they are looking at each other.

“Elephants live in a so-called ‘fission-fusion’ society, where they often separate and reunite, meeting after hours, days or months apart,” said cognitive and behavioural biologist Vesta Eleuteri of the University of Vienna in Austria, lead author of the study published this month in the journal Communications Biology.

Elephants, Earth’s largest land animals, are highly intelligent, with keen memory and problem-solving skills and sophisticated communication.

Female elephants of different family groups might have strong social bonds with each other, forming “bond groups.” Previous studies in the wild reported that when these groups meet, the elephants engage in elaborate greeting ceremonies to advertise and strengthen their social bond, Eleuteri said.

Male elephants have weaker social bonds, and their greetings may function more to ease possible “risky reunions” – a hostile interaction. They greet mainly by smelling each other, reaching with their trunks, Eleuteri added.

The study detailed around 20 gesture types displayed during greetings, showing that elephants combine these in specific ways with call types such as rumbles, roars and trumpets. It also revealed how smell plays an important role in greetings, often involving urination, defecation and secretions from a unique elephant gland.

Elephants may greet by making gestures intended to be seen, like spreading the ears or showing their rump, or with gestures producing distinct sounds like flapping the ears forward, or with tactile gestures involving touching the other elephant.

“We found that they select these visual, acoustic and tactile gestures by taking into account whether their greeting partner was looking at them or not, suggesting they’re aware of others’ visual perspectives. They preferred using visual gestures when their partner was looking at them, while tactile ones when they were not,” Eleuteri said.

Greeting behaviour has been studied in various animals.

“Many other species greet, including different primates, hyenas and dogs,” Eleuteri said. “Animal greetings help mediate social interactions by, for example, reducing tension and avoiding conflict, by reaffirming existing social bonds, and by establishing dominance status using different behaviors.”

The new research built on previous studies of elephant greeting behavior. The nine observed elephants – four females and five males – were “semi-captive,” freely roaming their natural environment during daytime and kept in stables at night.

Greetings used by the female elephants closely matched the behavior of wild elephants. The greeting behavior of the male elephants appeared to differ from their wild counterparts. Wild male elephants tend to be solitary, forming loose associations with other elephants.

The temporal gland, midway between the eye and the ear, secretes a substance called temporin containing chemical information about an elephant’s identity or emotional and sexual state. Elephants often use their trunks to check out the temporal glands of others.

“The urine and feces of elephants also contain chemical information important for elephants, like the identity of the individual, their reproductive state or even their emotional state,” Eleuteri said.

“Elephants might defecate or urinate during greetings to release this important information. Another option is that they do this due to the excitement of seeing each other. But the fact that the elephants often moved their tails to the side or waggled their tails when urinating and defecating suggests they may be inviting the recipients to smell them. Maybe they don’t need to tell each other how they’re doing, as they can smell it,” Eleuteri added.