Elephant trunk whiskers exhibit material intelligence, revealing the secret behind an amazing sense of touch

Amazing stuff!

"... The 1,000 whiskers that cover an elephant's trunk have unusual material properties that highlight where contact happens along each whisker, giving elephants an amazing sense of touch that compensates for their thick skin and poor eyesight. ..."

"To the point

• Sense of touch despite thick elephant skin: Researchers have discovered that the hairs on elephants' trunks are responsible for their extraordinary sense of touch. 
• Special material properties: Elephant sensory hairs have a stiff base and a soft tip, which enables them to precisely feel objects and recognize where contact is made. These properties are similar to the whiskers of cats and differ from the completely stiff sensory hairs of rats and mice. ...
• Applications in robotics: The findings will be used in the development of robot-assisted sensor technologies that mimic the stiffness gradient of elephant tactile hairs.

..."

From the editor's summary and abstract:

"Editor’s summary

Mammals such as cats and rats use whiskers to help sense their environment. In rats, the short whiskers and long whiskers resonate at different frequencies, helping rats map out their surroundings as the keratin-based fibers contact the edges and surfaces of nearby objects.

Elephants also have whiskers, which line the length of their trunks. Schulz et al. used micro–computed tomography imaging, electron microscopy, mechanical testing, and finite element analysis to map out the structure and properties of these whiskers.

At the base of the trunk, the whiskers are thick, circular, porous, and stiff, but they progress toward being thin, ovular, dense, and soft toward the tip, which contrasts with whiskers found in most other mammals. This combination of structure and form helps magnify the signals transmitted to the trunk. ...

Structured Abstract

INTRODUCTION

Animals have evolved a diverse array of sensing systems that help them traverse complex terrain, locate food, and detect predators. Many terrestrial and aquatic mammal species use specialized sensory hairs, known as whiskers, as active tactile sensory organs to monitor their environment. A follicle surrounds each whisker’s base with mechanoreceptors that respond to physical whisker stimulation and thereby extend the animal’s sense of touch. Most research focuses on how the geometry and/or neuromechanics of the whisker-follicle structure affect tactile sensitivity. This study analyzes variations in intrinsic whisker properties, including how porosity and stiffness change along the whisker.

RATIONALE

The boneless elephant trunk is covered with about 1000 whiskers that expand the sensory volume of this highly dexterous appendage. These whiskers do not possess the innervated local muscles that allow the characteristic “whisking” behavior commonly seen in rats and mice, and they cannot regrow, so we hypothesized they may also differ in other fundamental ways. This study applies several precise measurement approaches to characterize the geometry, porosity, and stiffness of Asian elephant (Elephas maximus) whiskers and uses mechanical simulation to show how the captured characteristics may affect trunk touch.

RESULTS

We measured the geometry, porosity, and material stiffness from the base to the tip of elephant whiskers and entered these properties into our open-source, customizable finite element model that allows whisker properties to vary longitudinally. This simulation was then used to compare elephant whiskers with rat whiskers, which exhibit uniform material stiffness along their length. By contrast, elephant whiskers showcase three independent functional gradients. The geometry of elephant whiskers shows a tapered ovular cross section, facilitating bending as the trunk extends between obstacles. Elephant whisker porosity is characterized by a network of hollow tubules in the inner cortex; this horn-like microstructure at the base merges into a dense whisker tip.

A porous base provides functional benefits of mass reduction and impact resistance, similar to the horns of bighorn sheep.

Our stiffness analysis shows that elephant whiskers transition from a stiff base (modulus of elasticity = 2.99 GPa) to a soft, resilient tip (0.0706 GPa), a shift of two orders of magnitude, although elephant body hair has approximately constant stiffness from base (2.20 GPa) to tip (1.15 GPa). The stiffness gradient of elephant whiskers provides two key benefits over homogenous whiskers: reduction of base stress during large deflection and amplification of signal differences along the whisker length, strengthening the encoding of contact location.

CONCLUSION

The geometry, porosity, and stiffness gradients of Asian elephant whiskers seem tuned to augment tactile sensing. Their tapered ovular geometry increases interaction with textures and allows preferred bending directions; the shift from a porous base to a dense tip reduces mass, increasing the whisker’s resonant frequency and reducing breakage; and the transition from a stiff base to a soft tip increases tip deflection and facilitates contact encoding along the whisker. The physical intelligence of these three functional gradients found together in elephant whiskers expands our understanding of touch and could inspire new approaches in artificial tactile sensing."

Elephant trunk whiskers exhibit material intelligence, revealing the secret behind an amazing sense of touch

Elephant trunk whiskers exhibit material intelligence (original news release)

Functional gradients facilitate tactile sensing in elephant whiskers (no public access)

Functionally graded keratin facilitates tactile sensing in elephant whiskers (preprint, open access)

... with a 3D-printed replica of an elephant's trunk hair, which helped the research team understand how a transition in material stiffness facilitates contact sensing in the tactile hairs of elephants and cats.

IUCN counted 135,690 African forest elephants (an increase of 16%) between 2016 and 2024 thanks to better detection using DNA signatures

Good news! How much is there still an undercount?

The IUCN (International Union for Conservation of Nature and Natural Resources) still claims African elephants "remain critically endangered." Really! I bet, the IUCN would still make this dubious claim when there a 500,000 or more African elephants. It's good for their business, I suppose!

"A recently published survey from the IUCN counted 135,690 African forest elephants between 2016 and 2024, 16 percent more than the previous attempt (2006-2015). The increase is partly due to better detection—this time around, the researchers used DNA signatures in dung to track individual elephants—so it’s not clear whether it reflects a real recovery."

"... This is the first time African Forest Elephants (Loxodonta cyclotis) have been assessed independently from African Savanna Elephants (Loxodonta africana), following their recognition as distinct species in 2021. ..."

Doomslayer: Progress Roundup - by Malcolm Cochran

DNA Methods Help Uncover Endangered African Elephants

DNA methods help uncover further African Forest Elephants – but species remains critically endangered "A new assessment of African Forest Elephants reveals an estimated 135,690 individuals1, with an additional 7,728 to 10,990 elephants based on more tentative ‘guesses’. Updated methods provide a clearer, more accurate understanding of the species’ status - revising population figures by an additional 16%, compared to figures published in 2016."

If you give an elephant an apple, it will gesture in many different ways for more

Amazing stuff! How intelligent are elephants?

"For elephants, communication is a complicated affair. These massive mammals bellow, trumpet, and rumble at frequencies we humans can’t hear. They detect one another’s seismic waves, touch each other with their trunks, and secrete chemicals from specialized glands. They even address each other with specific, name-like calls and combine visual signals—such as ear-flapping, trunk-swinging, and tail-waggling—with vocalizations when greeting in the wild.

Researchers haven’t confirmed, however, whether these prodigious pachyderms use their gestures to deliberately communicate what they want—a type of behavior known as goal-directed intentionality, which has previously only been observed in primates.

To find out, the authors of a new study presented semi-captive African savannah elephants with two trays: one empty, the other full of apples. The animals ended up using a wide range of gestures , which they only performed when an experimenter was present and looking at them; the animals repeated and elaborated their movements when they failed to receive the desired treats. ..."

From the abstract:

"A crucial feature of language is the ability to communicate cognitive goals to a specific audience, i.e. goal-directed intentionality. Core criteria for this ability include

(i) audience directedness: signalling in the presence of an attentive audience,

(ii) persistence: continuing signalling until goals are met, and

(iii) elaboration: using new signals following communicative failure.

While intentional use has been demonstrated in individual gestures in some non-primates, primates—in particular apes—show this ability across many gestures. But is goal-directed intentionality across many gestures restricted to primates?

We explored whether savannah elephants use many gestures with goal-directed intentionality. We presented semi-captive elephants with desired and non-desired items, recording their communicative attempts when an experimenter met, partially met or failed to meet their goal of getting the desired item.

Elephants used 38 gesture types almost exclusively when a visually attentive experimenter was present, demonstrating audience directedness.

They persisted in gesturing more when their goal was partially as compared with fully met but showed no difference in persistence when the goal was met or not met.

Elephants elaborated their gesturing when their goal was not met. We find goal-directed intentionality across many elephant gestures and reveal that elephants, like apes, assess the communicative effectiveness of their gesturing."

ScienceAdviser

Elephants gesture to signal what they want—just like us "New experiments show elephants use a wide range of movements to express their desires"

Investigating intentionality in elephant gestural communication (open access)

Elephants Shield Calves As Earthquake Strikes California with Molly Gambhir

Amazing stuff!

Elefantin trauert um beste Freundin nach 25 Jahren Partnerschaft

Sehr empfehlenswert und traurig!

Elephant displays sophisticated hose skills at Berlin Zoo and fascinates scientists

Very recommendable! Amazing stuff!

Captive Elephant showering can be captivating

Amazing stuff!

"When scientists spotted an elderly pachyderm named Mary using a hose to shower herself off at the Berlin Zoo, they were impressed with her tool-using prowess. Elephants are already famous for their smarts, but Mary’s dexterity with the hose—changing her grip to spray different parts of her body, an apparent understanding of water ballistics, and other skills—suggested an even more sophisticated insight than researchers had imagined. That wasn’t the end of the story, however.

It turns out that one of Mary’s comrades wasn’t as impressed. A much younger pachyderm named Anchali, seemingly in response to all of the attention Mary was getting, figured out how to shut the hose off—kinking it and stepping on it—a type of sabotage rarely seen among animals.

The observations further cement elephants as complex thinkers, says Lucy Bates, a behavioral ecologist who was not involved in the study. She says both behaviors suggest insight instead of simple trial-and-error. But that’s a difficult thing to prove without more observations, she says. “Obviously we don’t know if [Anchali’s] original intention was to stop Mary’s shower, but the fact she persevered and got better at doing this is quite compelling.”"

From the highlights and abstract:

"Highlights

• Elephants show elegant and elaborate water-hose tool use

• Elephants can use hoses in different ways depending on purpose

• Elephants show marked individual differences in showering behaviors

• Elephant Anchali disrupted water flow to showering elephant Mary by hose clamping

Summary

Since Jane Goodall’s famous observations of stick tool use by chimpanzees, animal tool use has been observed in numerous species, including many primates, dolphins, and birds. Some animals, such as New Caledonian crows, even craft tools. Elephants frequently use tools and also modify them. We studied water-hose tool use in Asian zoo elephants. Flexibility, extension, and water flow make hoses exceptionally complex tools. Individual elephants differed markedly in their water-hose handling. Female elephant Mary displayed sophisticated hose-showering behaviors. She showed lateralized hose handling, systematically showered her body, and coordinated the trunk-held water hose with limb behaviors. Mary usually grasped the hose behind the tip, using it as a stiff shower head. To reach her back, however, she grasped the hose further from the tip and swung it on her back, using hose flexibility and ballistics. Aggressive interactions between Mary and the younger female elephant, Anchali, ensued around Mary’s showering time. At some point, Anchali started pulling the water hose toward herself, lifting and kinking it, then regrasping and compressing the kink. This kink-and-clamp behavior disrupted water flow and was repeated in several sessions as a strict sequence of maneuvers. The efficacy of water flow disruption increased over time. In control experiments with multiple hoses, it was not clear whether Anchali specifically targeted Mary’s showering hose. We also observed Anchali pressing down on the water hose, performing an on-hose trunk stand, which also disrupted water flow. We conclude that elephants show sophisticated hose tool use and manipulation."

ScienceAdvisor

This elephant learned to use a hose as a shower. Then her rival sought revenge "Behaviors reveal sophisticated tool use—and possible “pranking”—among pachyderms"

Water-hose tool use and showering behavior by Asian elephants (open access)

Figure 1 Mary shows lateralized hose tool use and adjusts it to the showered body part

Figure 2 Mary adapts showering behavior to different water hoses

Figure 3 Anchali disrupts water flow to Mary by hose-kink-and-clamp behavior

Like Namibia before, Zimbabwe to Kill 200 Elephants to Feed People Amid Drought with Palki Sharma

Bad news! This is the first time since 1988. However, there is possibly a serious overpopulation of elephants going on in southern Africa.

Study proves elephants have a kind of name for each other

Amazing stuff!

Elephants use gestures and vocal cues when greeting each other, study reports

Amazing stuff!

"A team of animal behaviorists ... has found that elephants use gestures and vocal cues when they greet one another. ..."

From the abstract:

"Many species communicate by combining signals into multimodal combinations. Elephants live in multi-level societies where individuals regularly separate and reunite. Upon reunion, elephants often engage in elaborate greeting rituals, where they use vocalisations and body acts produced with different body parts and of various sensory modalities (e.g., audible, tactile). However, whether these body acts represent communicative gestures and whether elephants combine vocalisations and gestures during greeting is still unknown. Here we use separation-reunion events to explore the greeting behaviour of semi-captive elephants (Loxodonta africana). We investigate whether elephants use silent-visual, audible, and tactile gestures directing them at their audience based on their state of visual attention and how they combine these gestures with vocalisations during greeting. We show that elephants select gesture modality appropriately according to their audience’s visual attention, suggesting evidence of first-order intentional communicative use. We further show that elephants integrate vocalisations and gestures into different combinations and orders. The most frequent combination consists of rumble vocalisations with ear-flapping gestures, used most often between females. By showing that a species evolutionarily distant to our own primate lineage shows sensitivity to their audience’s visual attention in their gesturing and combines gestures with vocalisations, our study advances our understanding of the emergence of first-order intentionality and multimodal communication across taxa."

Elephants use gestures and vocal cues when greeting each other, study reports

Multimodal communication and audience directedness in the greeting behaviour of semi-captive African savannah elephants (open access)

Fig. 1: Illustrations of frequent body act types used by semi-captive African savannah elephants during greeting.

Thais struggle to live with wild elephants

Elephants are not always peaceful giants! Overpopulation could also be an issue.

Elephants have names for each other, just like humans

Amazing stuff! What a pachyderm surprise!

"... recent research has made the astonishing discovery that these highly intelligent gentle giants call each other by name. These specific and unique vocalizations are, of course, not as articulate as human speech but rather distinct low rumbling sounds. Still, they’re names nonetheless.
These remarkable findings position elephants as the first non-human animals to use a form of address that doesn’t mimic the receiver’s call, a trait previously observed in dolphins and parrots. ...
Some of these rumbles were played back to 17 wild elephants. When they heard their name, they were more likely to move quickly toward the sound source and vocalize faster in response. These rumbles were remarkably consistent with the receiving elephant. ..."

From the abstract:

"Personal names are a universal feature of human language, yet few analogs exist in other species. While dolphins and parrots address conspecifics by imitating the calls of the addressee, human names are not imitations of the sounds typically made by the name’s owner . Labeling objects or individuals without relying on imitation of the sounds made by that object or individual is key to the expressive power of language. Thus, if non-imitative name analogs were found in other species, this could have important implications for our understanding of language evolution. Here, we show that wild African elephants address one another with individually specific calls without any evidence of imitating the receiver’s vocalizations. A random forest model correctly predicted receiver identity from call structure better than expected by chance, regardless of whether the calls were more or less similar to the receiver’s calls than typical for that caller. Moreover, elephants differentially responded to playbacks of calls originally addressed to them relative to calls addressed to a different individual, indicating that they can determine from a call’s structure if it was addressed to them. Our findings offer the first evidence for a non-human species individually addressing conspecifics without imitating the receiver."

Elephants have names for each other, just like humans Elephants give each other unique names, groundbreaking study reveals

African elephants address one another with individually specific calls (open access)

Rhino, elephant, gorilla and other animal numbers rising in Uganda after years of poaching and killing

Good news! Good for tourism!

Rhino, elephant numbers rising in Uganda after years of poaching - agency | Reuters

About 250 elephants in Malawi were relocated to another national park in July to avoid overpopulation

Amazing stuff! 

"Some 250 elephants are to be driven 350km across the country to be relocated from Liwonde to Kasungu National Park in Malawi by the end of July.

This move aims to tackle over population at Liwonde, where cases of elephants straying into human communities around the park were becoming a concern. ...
This is the second translocation in three years, with 300 elephants moved to Nkhotakota Game Reserve in 2019. ..."

Hundreds of elephants in Malawi to be relocated | Africanews