Leopard Matching at Chimp&See
Updated October 2024
This mini-project will allow the science team to assess predator density at the Chimp&See research sites. We invite everybody to contribute, make matching proposals, discuss, and finally name, the leopards.
Leopards can be identified by their individually-recognizable fur pattern of dark rosettes and spots on a yellowish background. Further marks like injuries, scars, and cuts in ears can help make a match.
To approach this task we want to:
- Tag each leopard video with #leopard and the site name (e.g., #xenonbloom)
- Determine age class (cub, subadult, or adult) and sex (if possible) of the leopard
- Add tags for the visible body side(s) of the leopard to allow direct pattern comparison
- Give temporary IDs and/or names and record them in the spreadsheet and in the Known/Prospective leopard slide decks
- Discuss match proposals on a dedicated leopard discussion board.
Step 1: Hashtagging of leopard videos
Age class and sex ( #cub, #subadult, #adult / #male, #female)
We want to know sex and age class of each individual. Leopards are sexually dimorphic, i.e., the males and females have different body sizes. Note that it can be difficult to determine the size of a leopard that is seen alone.
Females are considerably smaller and have a more slender build, but an overlap (big female / small male) is possible. If an adult is seen with cubs, you can be sure that it is a female (the mother). Leopards are solitary animals and a family consists of a female and her most recent litter.
Males have testicles directly under the tail. If you see them, you can be sure that this is a male. If you don’t see testicles, you should not automatically assume the leopard is a female as lighting, camera angle, and blurry videos could make the testicles difficult to see. If direct comparison is possible, male leopards have a considerably heavier head and neck than females. The skinfold under the neck often looks a bit loose - building a “dewlap” - in mature individuals.
Adult individuals (or apparent adults) seen together could be a mating pair, a mother with her almost grown-up offspring, or nearly grown-up siblings walking together.
Tagging leopard body sides ( #right_side, #left_side, #back_side, #front_side )
Please tag all visible body sides of the individual(s) in each leopard video. If a leopard is moving around and shows different body sides, please add a hashtag for each side seen to enable a hashtag search.
#right_side and #left_side
This hashtag refers to the animal’s own body side as seen from the camera. That means: if an individual is facing to the right side of the screen, you can see its right body side. If an individual is facing to the left, you see the left side of its body.
#front_side and #back_side
The front side tag should be used for all views of the face of the leopard, forehead, and also the visible fur pattern of the throat.
The back side tag refers to the rear view of the animal, that means tail, hind limbs, and back are facing the camera. This tag also includes the view of a leopard very close to the camera when we can only see the spine and tail root from above.
Step 2: Proposing and discussing matches
Here is how you can identify (= match) individual leopards while comparing their fur pattern and present and discuss any match proposals.
Leopards have a distinctive fur pattern of dark rosettes and spots on a yellowish background. These rosettes and spots are uniquely arranged on each individual. The pattern is often so unique that a single rosette or combination of rosettes with a specific appearance can prove a match. Rosettes are mostly concentrated on the back, the flanks, the hindlimbs, and the upper tail; while the paws, throat, and underbelly are spotted. Ideally, we will find several matching rosettes/patterns, as that will improve our confidence in a match. Also, we’ve recently found that broad-scale patterns (i.e., whole rosettes with no other detail seen) can be used to match leopards in blurry/dark videos. At this time, two broad-scale patterns are needed to make a match.
Please keep in mind that the strong individuality of the fur pattern also means that the left and right sides of the body do not display the same pattern!
Specific individual marks like injuries, an unusual tail, or torn ears can prove a match without any reference to the fur pattern. Match proposals only based on these characteristics are welcome, too!
How to show a matching pattern?
There are several ways to discuss the fur pattern and indicate in a collage which part of the pattern best supports your match proposal. *
You can then describe with the help of the sections indicated in the figure below, where a recognizable pattern is found:
(1) head, (2) forelimb, (3) middle, (4) hindlimb, (5) tail.
Please be creative in your description. You could say for example: “the pattern on the upper right of the middle section looks like a fish with a big fluke”, or “it looks like a mushroom (or a letter) to me”. A description like this makes it easier for others to find your proposed recognizable pattern and assess for themselves.
You can modify screenshots or take snapshots from the video and point to the marker you want to discuss or frame the area as seen in the next figure.
You can even frame the proposed matching section and enlarge it for better comparison.
Don't worry about posting a “perfect” collage! As long as you are as clear as possible in describing the rosettes/patterns you think match, other volunteers will be able to comment!
If you think it’s helpful to draw lines on, or add arrows or spots to, a collage please include stills with and without the lines/arrows/spots. This allows volunteers to better assess potential matching patterns.
If you have any questions, please post on the leopard discussion board or in the respective matching discussions!