Cameras in the toad tunnels under Peninsula Road, which bisects the False Bay Nature Reserve, took 1 176 380 pictures this season. Fewer than one in a thousand show an endangered Western Leopard Toad (Sclerophrys pantherina).
Reading that many pictures by eye is not realistic, so an AI model does it instead. It was built by Joshua Salako at the African Institute for Mathematical Sciences (AIMS) South Africa and Nature Connect, which installed the tunnels, runs it every week through its staff portal.
Reading a million pictures
The tunnel cameras took more than a million pictures between 2023 and 2025. For his master’s research, Joshua developed a way to detect the toads automatically. His study, Annotation-Efficient Object Detection of Endangered Western Leopard Toads in Camera Trap Imagery for Assessing Wildlife Tunnel Use, was written with Lorène Jeantet of AIMS and Kim Gordon of Nature Connect.
It begins with just 20 labelled pictures, improves the contrast of dark night frames, compares four detection models and lets the computer choose which pictures are most worth labelling next.
Applied to the 2023 to 2025 pictures, the best-performing model found 730 sightings in 387 separate events. It also mapped 15 re-encounters, which are toads pictured again on the opposite side of the tunnels. In October 2026, Joshua published his application, AmphiLens, openly, with its code, trained models and an installation guide, so any project team working with camera traps can use it.
The 2026 season
Nature Connect Media and Communications Manager Llewellyn Williams built AmphiLens into the organisation’s staff portal. It includes a review page where the team confirms each picture the model flags, an updated model trained on all toad and other amphibian images identified between 2023 and 2025, and a feature that helps match pictures of the same toad.
Since October, the system has checked 2 160 620 pictures from the 2023 to 2026 seasons. Of this season’s 1 176 380, 384 show a toad. These count as 130 toads seen, because pictures of the same toad a few minutes apart count once. The busiest night was 17 August, with 16 toad visits.
A Western Leopard Toad pictured by the camera at the Zeekoevlei end of tunnel 4 on 18 August 2026, found by Joshua’s model and confirmed by Nature Connect’s team.
Telling one toad from another
Every Western Leopard Toad carries its own pattern of dark patches edged in yellow, and keeps it for life. The portal compares those patterns across pictures and puts forward pairs that may be the same toad. A person confirms every match before it counts.
The first confirmed matches already show toads crossing. One toad, T2026-7, was pictured at the Rondevlei end of tunnel 4 at 00:38 on 21 August and at the Zeekoevlei end eight minutes later, by the cameras’ clocks. Of the 36 points the computer matched on its back, 35 land on each other when the two pictures are laid together.
Toad T2026-7 at the Rondevlei end of tunnel 4 (left, 00:38) and the Zeekoevlei end (right, 00:46) on 21 August 2026. Blue dots are points that line up on both backs, and numbered outlines mark the same spot on each.
The same two pictures with the right toad’s spots turned and laid on the left toad’s: 35 of 36 points land on each other.
Nature Connect’s team is still confirming the season’s matches and will share the number of individual toads and crossings once the checks are complete. That review is the slowest part of the work, and it is what turns a likely match into a confirmed crossing.
Faster than the camera
The cameras take a picture every 15 seconds. Toads are cold-blooded, so the heat sensors that usually trigger a camera trap do not detect them.
On 17 August, the camera at the Rondevlei end of tunnel 3 pictured an empty floor at 21:14:53, a toad in mid-crawl at 21:15:09 and an empty floor again at 21:15:25. The toad crossed the whole of the camera’s view in less time than the camera waits between pictures. A toad moving that quickly can pass a camera without being pictured at all, so the real number of crossings may be higher.
Camera 3R, Rondevlei end of tunnel 3, 17 August 2026. The floor is empty, a toad crosses in mid-leap, blurred by its own speed, and the floor is empty again.
What the season shows
The busiest night, 17 August, came under a thin crescent moon, with the temperature falling no lower than 10.5°C. Across all four seasons, most toads moved when the night was between 12°C and 17°C, and the single busiest temperature was 15°C. With four seasons of pictures from one place, those patterns can now be compared year on year.
On 18 August at 20:30, the camera at the Rondevlei end of tunnel 6 pictured two toads, one on top of the other. This is amplexus, the mating position, in which the male clasps the female from behind. The female lays her eggs while the pair is in amplexus, thousands of them in long strings of jelly and the male then fertilises them.
Two Western Leopard Toads in amplexus, pictured by the camera at the Rondevlei end of tunnel 6 on 18 August 2026 at 20:30.
Built on years of fieldwork
Nature Connect installed the first two tunnels with William Dau Civils in 2021, with funding from Fondation Ensemble and Leisure Charitable Trust. Four more followed in 2023, funded by The Mohamed bin Zayed Species Conservation Fund and Forvia Foundation. The camera traps, sponsored by Hensoldt, have been recording the tunnels since 2023, and Nature Connect’s research monitors and volunteers have logged toad activity since the first tunnel opened.
‘My research is an intersection between artificial intelligence and ecology,’ Joshua said when Nature Connect first shared his work in July. His model now reads every picture from the breeding season and each confirmed crossing adds to a growing body of evidence that safe migration is possible when partners work together.
Now in its 25th year, Nature Connect says every season of data brings new questions and the team looks forward to learning the answers.
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Picture: Supplied
