# Identification of the Anteroposterior and Mediolateral Position of Lion Paws and Tracks Using 3D Geometric Morphometrics

> Was that track left by a front or a hind foot, a right or a left? Mixing them up can turn one lion into two. Using 3D models built from ordinary photos of lion paws and tracks in two South African parks, researchers could tell which foot made a track with up to 91% accuracy, a step towards identifying individual lions from their tracks.

Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/2017-marchal-lejeune-identification-anteroposterior-mediolateral-position/

## Citation and access

- **Authors:** Antoine F.J. Marchal, Philippe Lejeune and P.J. Nico de Bruyn
- **Year published:** 2017
- **Journal or source:** African Journal of Wildlife Research
- **Full citation:** Marchal, A.F.J., Lejeune, P. and De Bruyn, P.J.N. 2017. Identification of the anteroposterior and mediolateral position of lion paws and tracks using 3D geometric morphometrics. African Journal of Wildlife Research 47(2): 106–113.
- **DOI:** 10.3957/056.047.0106
- **Access status:** Hosted (freely available elsewhere)
- **PDF:** https://www.originalwisdom.com/wp-content/uploads/2026/11/2017_Marchal_and_Lejeune_etal_identification-of-the-anteroposterior-and-mediolateral-position-of-lion-paws-and-tracks.pdf

## Tags

- **Species:** Mammals > Lion
- **Region:** Africa > South Africa
- **Tracking:** Gaits; Track photographs; Tracking; Tracks; Tracks and signs identification
- **Methods and technology:** Analysis of variance (ANOVA); Camera traps; Direct observation
- **Data type:** New field data
- **Observer qualification:** Not reported
- **Discipline:** Wildlife tracking
- **Year published:** 2017

## Detailed keywords

- **Species:** Studied: African lion (Panthera leo), paws of 39 captured lions and 182 tracks from 12 trails. Mentioned from earlier footprint studies: tiger (Panthera tigris), cheetah (Acinonyx jubatus), mountain lion (Puma concolor) and snow leopard (Panthera uncia).
- **Location and habitat:** Hluhluwe-iMfolozi Park (about 900 km²) and Tembe Elephant Park (about 300 km²), KwaZulu-Natal Province, South Africa, both managed by Ezemvelo KZN Wildlife. Tracks were sampled in riverbeds and on dirt (sandy) roads.
- **Topics:** identifying which foot made a track (front or hind, right or left); anteroposterior (front/hind) and mediolateral (right/left) position; digital three-dimensional (3D) models of paws and tracks; close-range photogrammetry; landmark-based geometric morphometrics; shape differences between paws and tracks; track distortion by substrate; repeatability of landmark placement between operators; groundwork for identifying individual lions from their tracks; pugmark census criticism; low-cost, non-invasive monitoring; possible role for citizen scientists and community members.
- **Statistics or models:** 12 fixed landmarks placed by hand; generalized Procrustes analysis (GPA); Procrustes analysis of variance (ANOVA); repeatability from a repeated-measures nested ANOVA; principal component analysis (PCA); linear discriminant analysis (LDA) with jack-knifed (leave-one-out) predictions; thin-plate spline deformation grids; Geomorph package in R; Agisoft PhotoScan for the 3D models. Significance at P ≤ 0.05.
- **Data type:** New field data: paws photographed during night-time captures for routine management, and tracks photographed along trails less than 24 hours old. Dates of data collection are not given (received by the journal September 2016). Possible inconsistency: Table 1 lists the adult female HiP 618 on two separate rows (three paws and four paws), so that animal appears to have contributed seven paw records; the text still gives eight adult females, which matches the number of different IDs.

## Synopsis

### 1. What they did

Tracks are a cheap, non-invasive way to study elusive animals such as big cats, and several studies have tried to tell individual felids apart from their footprints. A known problem, raised in India’s tiger “pugmark census”, is that a track from one foot can be wrongly compared with a track from another foot of the same animal, so one animal is counted as two. The authors set out to build an accurate, consistent and objective way to tell which foot made a lion track: front or hind, right or left.

- Paws. In Hluhluwe-iMfolozi and Tembe Elephant Parks, South Africa, they photographed 132 paws from 39 lions of both sexes and all ages (adults, subadults and juveniles) while the lions were captured at night for routine management by Ezemvelo KZN Wildlife staff, including a wildlife vet.

- Tracks. They photographed 182 tracks from 12 trails (7 to 31 tracks each) in riverbeds and on dirt roads, after seeing the lions directly or after a lion passed one of six camera traps placed along game paths and near waterholes. All trails were less than 24 hours old and showed a walk in which the hind foot landed beyond the front track. Which foot made each track was worked out from its place in the sequence of tracks.

- 3D models. For each paw or track they took 9 to 15 overlapping photos from different angles, with a scale bar, and turned them into a 3D model with photogrammetry software.

- Shape analysis. They placed 12 landmarks on each model: four points on the lobes of the main pad and the two ends of each toe along its long axis. Five people with no experience placed the landmarks four times on 10 paws and 10 tracks to test how repeatable this was. They then compared shapes and tested how well a statistical classifier could assign each paw and track to the right foot.

### 2. What they found

- Repeatability: landmark placement was 88.8% repeatable on paws and 73.7% on tracks.

- Accuracy: the best classification reached 95.45% for paws and 91.21% for tracks. With only the first two shape components, accuracy was already 84.09% for paws and 88.46% for tracks.

- Paws versus tracks: the main shape difference was the spread of the toes.

- Right versus left: the outer (smallest) toe is shorter and sits closer to the main pad, while the toe two digits in from it (the middle digit, between the outer toe and the dewclaw) sits furthest from the pad and marks the highest point of the paw or track. In tracks, the inner bottom lobe of the main pad tends to sit higher than the outer one.

- Front versus hind: front paws and tracks are larger and rounder than hind ones.

- Missing tracks: 30 tracks in the trails were missing (destroyed by other tracks) or too poor to use; 80% of these were front tracks.

### 3. What they concluded

- With just 12 landmarks, lion paws and tracks have shapes complex enough to tell front from hind and right from left accurately and consistently.

- Tracks were classified a little less accurately than paws, probably because the paw and the ground interact in complex ways and distort the track. This seems stronger in front tracks, likely because lions, like most four-legged animals, carry most of their weight on their front legs.

- The study used good-quality tracks in riverbeds and on sandy roads; tracks on other substrates still need testing.

- Future work: automating landmark placement using the 3D information, adding more landmarks to identify age, sex and individuals, testing bias between people recording the tracks, and trying cheaper cameras and free software.

- The authors recommend this method in future studies that compare tracks between individual lions.

### 4. How tracking was or was not used

Tracks were the study material. The researchers found fresh trails (less than 24 hours old) of lions they had watched or that had passed camera traps, and recorded continuous sequences of tracks, defining a trail as a continuous sequence of tracks from one animal. They identified which foot made each track from its position in the sequence, using a walking gait in which the hind foot oversteps the front track, following Liebenberg’s field guide and Practical Tracking. They also judged track quality, discarding tracks where a landmark was missing or distorted.

### 5. Tracker or observer certification

Not reported. The paper does not say who found the trails or assigned each track to its foot. This matters because those foot assignments are the “known answers” the classifier was tested against. The five people who tested landmark placement had no prior experience of placing landmarks.

### 6. Other technologies, skills or innovations

- Close-range photogrammetry with ordinary digital single-lens reflex cameras (Nikon D7100 and D80) and a scale bar; 3D models built in Agisoft PhotoScan Professional.

- Landmark-based geometric morphometrics in R (Geomorph package).

- Camera traps (Cuddeback Attack), checked daily, to confirm which lions made the tracks.

- The authors thank the Carnegie Institution for Science for letting them use the tracking frequencies of collared lions.

### 7. Implications for conservation (from the paper)

- Telling individual lions apart from their tracks would be a practical, low-cost, non-invasive monitoring tool with major implications for conservation, management and research.

- The field kit is just a commercially available camera and a scale bar. The simple protocol could involve citizen scientists and community members, making photogrammetry suited to long-term monitoring in remote areas with few resources, provided someone else does the 3D processing and analysis (for example through an online platform).

### 8. Implications for tracking (Original Wisdom's observations)

_These are Original Wisdom's observations, not the authors'._

- The study rests on a basic tracking skill: reading a trail to know which foot made each track. The computer method was trained and tested against those assignments, so the quality of the tracking behind the “known answers” sets the ceiling for the method.

- The shape cues the authors describe (front tracks larger and rounder; the outer toe shorter and closer to the pad) are the kind of features trackers already use, and the paper gives them measured support for lions.

## Cite this summary

Lawrence, K. 2026. Summary of: Identification of the Anteroposterior and Mediolateral Position of Lion Paws and Tracks Using 3D Geometric Morphometrics (Marchal and Lejeune et al., 2017). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/2017-marchal-lejeune-identification-anteroposterior-mediolateral-position/