Rory Hensman Conservation & Research Unit (RHCRU)

The late Rory Hensman learnt so much from observing wild elephants and living with tamed and trained elephants. His wish was that through education and knowledge of the wonders of this animal, we humans would be motivated to look after them. As we head into a modern world where wildlife has little place next to poor communities and economic gain, knowledge, understanding and ambassadorial animals will be the deciding factor between survival and extinction.

The Rory Hensman Conservation & Research Unit (RHCRU)  aims to establish an elephant research centre of excellence, which is unbiased and un-swayed by “who funds the project” and by emotional thinking. The intention is to promote the potential benefits to human society, wildlife and conservation efforts.


Until recently, the prevailing theory about male African elephants (Loxodonta africana) was that, once adult and sexually mature, males are solitary and targeted only at finding estrous females. While this is true during the state of ‘musth’ (a condition characterized by aggressive behavior and elevated androgen levels), ‘non-musth’ males exhibit a social system seemingly based on companionship, dominance and established hierarchies. Research on elephant vocal communication has so far focused on females, and very little is known about the acoustic structure and the information content of male vocalizations. Using the source and filter theory approach, we analyzed social rumbles of 10 male African elephants. Our results reveal that male rumbles encode information about individuality and maturity (age and size), with formant frequencies and absolute fundamental frequency values having the most informative power. This first comprehensive study on male elephant vocalizations gives important indications on their potential functional relevance for male-male and male-female communication. Our results suggest that, similar to the highly social females, future research on male elephant vocal behavior will reveal a complex communication system in which social knowledge, companionship, hierarchy, reproductive competition and the need to communicate over long distances play key roles.

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scent detection

An elephant has a far superior sense of smell than that of a good dog and has the capability of detecting scents a substantial distance away from the source (up to 4km). Research is being carried out in the areas of tracking, search and rescue, anti-poaching, disease detection and contraband detection with the end goal of making elephants valuable to local communities that live with them.

Currently the elephant are able to detect small traces of TNT from 100m away. They would be a valuable tool to monitor the effectiveness of mine detecting dogs. The value here lies in land mine area reduction programs where vast areas suspected to have landmines can be quickly scanned by sniffing SAMPLES from the suspected areas. At no time is the intention to release elephants into landmine areas.

Article in Applied Animal Behaviour Science

reducing human-elephant conflict

Through better understanding of body language and vocalizations this area of research aims to find ways of reducing human elephant conflict. Vocalizations could be played back to wild elephant as a way to warn them of danger or to detract them from getting close to villages.

By utilizing tamed and trained elephant to traverse trans-frontier corridors we hope to encourage wild elephants to follow in our tamed elephants' footsteps and begin to use these corridors instead.

Contraception is another area of research. Since less and less land is available for wildlife, over population is a concern. We are researching ways of curbing reproduction in order to protect existing populations and the land they live on. 

Worth reading!

Towards an automated acoustic detection system for free-ranging elephants


The human–elephant conflict is one of the most serious conservation problems in Asia and Africa today. The involuntary confrontation of humans and elephants claims the lives of many animals and humans every year. A promising approach to alleviate this conflict is the development of an acoustic early warning system. Such a system requires the robust automated detection of elephant vocalizations under unconstrained field conditions. Today, no system exists that fulfils these requirements. In this paper, we present a method for the automated detection of elephant vocalizations that is robust to the diverse noise sources present in the field. We evaluate the method on a data-set recorded under natural field conditions to simulate a real-world scenario. The proposed method outperformed existing approaches and robustly and accurately detected elephants. It thus can form the basis for a future automated early warning system for elephants. Furthermore, the method may be a useful tool for scientists in bioacoustics for the study of wildlife recordings.

Establishing the fundamentals for an elephant early warning and monitoring system


The decline of habitat for elephants due to expanding human activity is a serious conservation problem. This has continuously escalated the human–elephant conflict in Africa and Asia. Elephants make extensive use of powerful infrasonic calls (rumbles) that travel distances of up to several kilometers. This makes elephants well-suited for acoustic monitoring because it enables detecting elephants even if they are out of sight. In sight, their distinct visual appearance makes them a good candidate for visual monitoring. We provide an integrated overview of our interdisciplinary project that established the scientific fundamentals for a future early warning and monitoring system for humans who regularly experience serious conflict with elephants. We first draw the big picture of an early warning and monitoring system, then review the developed solutions for automatic acoustic and visual detection, discuss specific challenges and present open future work necessary to build a robust and reliable early warning and monitoring system that is able to operate in situ.

Visualizing Sound Emission of Elephant Vocalizations: Evidence for Two Rumble Production Types


Recent comparative data reveal that formant frequencies are cues to body size in animals, due to a close relationship between formant frequency spacing, vocal tract length and overall body size. Accordingly, intriguing morphological adaptations to elongate the vocal tract in order to lower formants occur in several species, with the size exaggeration hypothesis being proposed to justify most of these observations. While the elephant trunk is strongly implicated to account for the low formants of elephant rumbles, it is unknown whether elephants emit these vocalizations exclusively through the trunk, or whether the mouth is also involved in rumble production. In this study we used a sound visualization method (an acoustic camera) to record rumbles of five captive African elephants during spatial separation and subsequent bonding situations. Our results showed that the female elephants in our analysis produced two distinct types of rumble vocalizations based on vocal path differences: a nasally- and an orally-emitted rumble. Interestingly, nasal rumbles predominated during contact calling, whereas oral rumbles were mainly produced in bonding situations. In addition, nasal and oral rumbles varied considerably in their acoustic structure. In particular, the values of the first two formants reflected the estimated lengths of the vocal paths, corresponding to a vocal tract length of around 2 meters for nasal, and around 0.7 meters for oral rumbles. These results suggest that African elephants may be switching vocal paths to actively vary vocal tract length (with considerable variation in formants) according to context, and call for further research investigating the function of formant modulation in elephant vocalizations. Furthermore, by confirming the use of the elephant trunk in long distance rumble production, our findings provide an explanation for the extremely low formants in these calls, and may also indicate that formant lowering functions to increase call propagation distances in this species'.

understanding elephant welfare


With smaller and smaller habitats and closer interactions with man, there is a case for having more animals in captivity to protect them. This scenario demands that elephant kept in captivity have all their welfare needs met and are well looked after. 

By studying an elephant's foot and gait, this research is useful in zoos so that elephants can avoid arthtritis in their ankles. We are also doing research on an elephant's spine.

protecting the environment

With the continuing pressure on land and resources, wildlife are being forced into smaller and smaller areas. This puts pressure both on the land, the animals and on man. This research area attempts to answer questions related to the carrying capacity of land, how elephant choose their feed, the effect of changes of season on their mood, and whether feed has an effect on musth. 

Our aim is an elephant research centre of excellence, which is unbiased and un-swayed by “who funds the project” and by emotional thinking. For this we rely on money from donations and from our guests.