FREQUENTLY ASKED QUESTIONS:
Female Mrembo as a cub with her mother and littermates and as an adult
BACKGROUND of the METHOD and DETAILS
The identification of individuals provides researchers with important information on population, distribution, home ranges/territories, composition, and dynamics of populations which is necessary to develop conservation strategies.
Photographic identification is a simple, non-invasive technique for identifying individuals using distinctive features such as coloration, stripe or spot patterns and other unique characteristics depending on the species.
The tip of the tail can be white, black or plain, and with or without spots. The tail can also have up to 6 rings, followed by half-broken rings which appear as different patterns on both its sides and thus can be used as a prime identification pattern.
The spots on cheetah face and chest are relatively small and are only well seen from a short distance. In captivity the method of recognition of a cheetah by face marks is obviously more common, for the animals are of limited number and are always close to an observer. However, in the field, the animal is often too far from the observer and even with high-resolution equipment; it may be difficult to spot the details. The body spots, their brightness and position are larger, and more useful, but as we will see later, there can be problems with this method as well. I have found limbs and tail are the most useful for identification.
There are two basic ways of making comparisons between sightings to check if they refer to the same individual. Most common one is based on the visual examination of the photos and the alternative represents 3-dimensional (3-D) computer-matching system. The latter, for instance, is used in the Serengeti Cheetah project.
Computer-aided matching system is based on examination of distinctive features (spot patterns) in the middle part of the cheetah body. This program has both advantages and disadvantages over visual comparison of photos. The software turns the picture taken from a certain angle into the frontal plane, matching it to the database to identify individuals. However, computer-made comparisons of photographs at skewed camera angles have a tendency to reduce the coefficients of similarity. As the angle distorts the whole pattern of the skin it might be difficult to use such picture for visual comparison with one taken from the straight side, even of the same individual.
Without the computer program, a simpler method based on visual analysis of the images of only the cheetah’s leg and tail photos can be suggested. After working closely with cheetahs for 17 years in different facilities (Moscow Zoo (Russia), White Oak Conservation Center of Species (Florida, USA), Cheetah Conservation Fund (Namibia), I received a position as an assistant researcher at the Masai-Mara Cheetah Conservation project in Kenya. One of my duties was to identify cheetahs we had observed and photographed during field work. After our first 15 days, we had 20 sightings of 37 individuals, and I had more than 100 photos, as well as hours of video to work with. With those, I then had to identify precisely how many individuals were present. In the beginning, I used tail and sex as a base. As animals we observed mostly were shy, we could take pictures only from a long distance, which affected the quality of pictures. I decided not to use cheetah faces because it was difficult to use small spots and distinctive tear marks from unclear pictures. In addition, face expression affects the position of spots and tear marks. Pictures of one animal either hissing or relaxing can look different, while two images of different hissing animals can look very similar.
One cheetah (left and middle images) and another cheetah (right image)
I tried to use only the torso, but I found that on the pictures taken from an angle the whole pattern of the skin was distorted, and it was difficult to compare them with those taken perpendicularly to the axis of the body. Looking through the images, I realized that the only parts of the body that had almost stable pattern visibility were tail and limbs.
This method was successfully used for identification of all individuals in the study area. Having this database (photo album) with us in the field, allowed us almost instant identification of known and unknown individuals.
Resy in 2001 (left) in 2008 (right) and 2011 (below).
Unique colour patterns circled
This method has two main advantages: first, it allows using a certain variety of field photo and video equipment, including film and/or digital cameras. However, usage of a digital camera is preferable. Second, as I found out, there were no visible changes in the patterns of the tail rings and limbs spots seen on a pictures taken even up to an angle of 45 degrees, and therefore did not affect the accuracy of comparison.
Pictures of Resy: distinctive “flower” pattern is marked. There were no visible changes in the patterns of the tail rings and limbs spots (circled) seen on a picture taken even up to an angle of 45 degrees
The photo library (catalogue) is meant for building up a data base/catalogue of individuals for the further use in field work. It helps to compare already identified individuals with new ones, even if new pictures have been taken only from one side of its body, or it is sitting, or only part of its tail and/or front/hind leg is visible.
It is very important to point out that photographing/video-recording of animals in the wild, especially in unprotected areas can be very challenging process. If the animal is very shy, it might be extremely difficult to take a clear picture from the side. It is sometimes necessary to give the animal enough time to get used to the presence of the observer before he/she is able to get a clear shot. Our experience suggests up to 120 min is needed for a wild cheetah to get used to a vehicle and display natural behaviour. If the animal is resting, it could take on average 30 min. for the animal to start moving. It is always better not to approach a wild animal closely, keeping a distance within 20-30m. In case of fast running cheetah, which can instantly escape into thick bush, a video camera with fast shutter might be of a great use.
The method described above is economically and technically affordable and has been used successfully for the identification of all observed individuals in the study area.
HELP US MONITORING CHEETAHS in the MARA and MERU!
You can help us by sending some of your photos of walking/standing/sitting cheetahs (profiles of both sides are preferable) taken in the Mara/Meru in 2000 to date, to firstname.lastname@example.org, so we can tell what is known about the cheetah you observed. Your photographs will be used for identification purpose only and will not be passed to a third party.
THANK YOU ALL FOR YOUR CONTINUOUS SUPPORT!