Rhino Footprint Identification Project

Background to Rhinowatch - Sky and Zoe Jewell

We established Rhinowatch in 1991, to census and monitor endangered species. We are especially interested in the application of non-invasive techniques, and have developed a rhino footprint identification technique which has given a very high degree of accuracy for both censusing and monitoring (Jewell, Alibhai and Law, 2001). The latest information on Sky and Zoe's work is available at Wildtrack.org.

Our interest in the application of non-invasive techniques for wildlife monitoring has been fostered by our research findings that repeated immobilization of female black rhino for invasive management (primarily radio-collaring) has a negative impact on their fertility (Alibhai, Jewell & Towindo, 2001). Similarly our data showed that radio-collars had a very high failure rate (Alibhai & Jewell, 2001).

In the last 11 years we have worked in Zimbabwe and Namibia, on black and white rhino. Last year we began to develop the footprint identification technique for Tigers, and plan to extend the range and scope of the technique further whilst continuing our rhino work. Our research centre is currently based in Portugal.

We believe that the future of wildlife conservation depends to a large extent on our ability to develop non-invasive, cost-effective and sustainable methods of censusing and monitoring endangered species. Many current techniques employed for conservation (radio-collaring, tagging, notching etc) are expensive, sometimes ineffective and often unsustainable. Developing countries, home to many endangered species, are best able to sustain and manage techniques which are inexpensive and utilise indigenous skills. We believe that the footprint identification technique has a very promising future in wildlife conservation, and has shown itself to be adaptable to other endangered species.

In 2002 our technique was nominated by SAS, the largest private software company in the world, for an award in the 2002 Computerworld Honors programme. In June 2002 we attended the award ceremony in Washington USA and were honoured to be presented with the award for Environment, Energy and Agriculture. Full details of the award are available at www.cwheroes.org

Sky Alibhai and Zoe Jewell accept the award for Environment, Energy and Agriculture at the Computerworld Honors Awards in Washington DC.

The footprint identification technique

(From left to right) Zoe Jewell, DNP Scout Sgt. Richards and Sky Alibhai photographing a black rhino spoor

The footprint identification technique was developed to address the need for an objective, non-invasive and cost-effective method for the identification of individual rhino, for use in censusing and monitoring. A full description of the technique is given in Jewell et. al. (2001). To give a brief outline, digital photographs are taken of rhino footprints and downloaded onto a laptop or PC. Landmark points are placed on the image and measurements made between them. Statistical analyses allow animals to be identified from the resulting "geometric profile". This information can be used both by researchers for the study of the behaviour and ecology of the rhino, and by managers for deployment of anti-poaching patrols for protection of the rhino. It has several advantages over currently used monitoring methods.

It is non-invasive to the animal, and therefore does not affect the natural behaviour of the animal or compromise its fertility. This is particularly important when dealing with an extremely endangered species.
It is cost-effective, particularly in comparison with other methods such as radio-collaring. The only cost of running the project for a population of 50 black rhino, for example, is the initial cost of technical equipment (about US$5,000) with few if any recurrent annual costs. In comparison the cost of monitoring the same population using radio-collaring would be US$85,000 annually.
It fully utilises the skills of indigenous people who are employed to protect the black rhino. In Zimbabwe, many of these scouts, members of the DNP, are talented trackers who are able to locate and photograph rhino tracks as a part of their normal routine anti-poaching patrols in the bush, 365 days a year. By enabling scouts to protect the rhino in their own areas effectively, this technique empowers local communities and brings with it benefits for all members. Many other monitoring techniques rely heavily on imported expertise and involve local people only in a superficial or temporary way. Because it is based on a traditional bushman tracking technique, used for generations by indigenous peoples, it is appropriate and intuitive for use in developing countries, but also has the benefit of being able to fulfil objective scientific criteria.
It provides truly comprehensive data about rhino ranging behaviour. Radio-tracking of black rhino can only be done safely during daylight hours and consequently will not provide information about ranging at night, which is when rhino are most active. By collecting spoor from watering holes it is possible to find out where rhino were drinking at night, which may be some distance away from their daytime resting areas.
It is a technique which can be adapted for other endangered species which leave a footprint, particularly where the sighting of these animals is difficult, which is the case for rhinos, and many other nocturnal/elusive species or those which exist at low density.

White rhino foot

White rhino footprint, processed ready for analysis

Rhinowatch research in Namibia

In 1999 we were invited to conducted a full census of the white rhino population at the Otjiwa ranch in Namibia, using an adaptation of our footprint identification technique originally developed for black rhino. At this time the Otjiwa population was the largest of white rhino on private land in the world. The technique gave accuracy for both censusing and monitoring of over 90%. In 2002 we revisited this population and were able to update the census using the same technique.

A white rhino cow and calf at Otjiwa Ranch, Namibia.

Map of Namibia, showing Otjiwa Ranch

The Sinamatella and Otjiwa datasets have shown that the technique can be used very effectively to identify individual rhino for censusing and monitoring. There are, however, several ways in which the technique could perhaps be refined and made more flexible, and we are currently working on this.

Automation of certain sections of the software to facilitate the necessary statistical manipulations and development of the range of possible tests/visualisations for spoor analysis.
Assess the possibility of ageing and sexing rhino from footprints. Early indications are that this may be possible, but more data are needed. The data collected from Otjiwa in late 2002 will be important to this investigation, and further data will be collected from the same population in November 2003.

Adaptation of the footprint technique for the Tiger and other endangered species.

In 2002, in a joint project with SAS and the Carnivore Preservation Trust (CPT) in North Carolina (N.C.), USA, we undertook a preliminary trial on the identification of individual Tigers from their footprints. By re-calibrating the technique for the tiger footprints we have been able to identify 10 individuals, with very high accuracy. This process has involved the identification of specific landmark points and variables which can be used to separate individuals. There is no reason why it could not be so applied for other endangered species.

We now plan to conduct field trials with three research groups, in India, Bangladesh and Siberia. Once footprint photographs have been gathered we will field-test the technique. We hope that these trials can be run in conjunction with established objective tiger monitoring techniques, such as camera trapping and transect work, which will have the benefit of ground-truthing the spoor technique. If it works well, the spoor technique will have the additional advantage that it is non-invasive, particularly cost-effective and spoor can be collected from anywhere impressions are left, not just at trapping points or on transects. Once the technique has been proven in local conditions, we will continue to work with local scientists to ensure that all the technology is in place for them to continue the work themselves. Our future aim is then to adapt this technique for other endangered species, always working in close conjunction with local field biologists and other scientists.

Tiger spoor photograph, ready for processing

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