BIODIVERSITY · AI

Karibou Project

Automatically sorting camera trap images to keep only those where an animal is present.

Karibou Project: wildlife detection using artificial intelligence

THE CHALLENGE

Hundreds of thousands of images, very few animals

Installed in the tundra, camera traps are triggered continuously. Over a season, they produce hundreds of thousands of images, the vast majority of which contain no animals at all. Sorting them by hand takes weeks of work.

The Karibou project has two objectives:

  • automatically discard a large share of the images with no animals;
  • keep all the others for a human eye to examine.
Camera trap image in the tundra, with an animal spotted in a red frame
An animal spotted in the landscape: just a few pixels.

OUR APPROACH

We see the animal because it moves

In these vast open landscapes, a caribou or a goose often measures only a few pixels: far too small for standard detection systems. The Karibou project therefore uses movement, analysing each image together with the previous and the next one. Discover our approach to AI applied to the environment.

Previous image, annotated image, next image and colour composite
Previous image, annotated image, next image and colour composite: movement makes the animal stand out.

Time window

Each image is compared with its immediate neighbours to bring out whatever is moving.

Events

A sequence of consecutive images forms an “event”, the unit that the model keeps or discards.

Assisted sorting

The model does not replace the expert: it spares them from examining empty images.

THE DATA

Eleven memory cards, seven sites, 318 events

105,320

images collected

7

monitoring sites

318

annotated events

2,486

annotated images

The annotated events mainly involve geese (142), unidentified birds (60) and caribou (41), but also other mammals, gulls and passing people or vehicles.

93% of annotated images have an almost identical neighbour in the same burst. To avoid an overly optimistic evaluation, the model is therefore never validated on a random sample of images, but always on an entire site held out.

Example of caribou detection with the time window
Example of a detected caribou: the time composite brings out the moving animal.

THE DIFFICULTIES

Imperfect annotations

  1. The position of annotations is offset depending on the camera.
  2. One annotation may correspond to one or several animals.
  3. Some images are flagged as containing an animal, but without coordinates.

THE METRIC

Never miss an animal

We measure the proportion of empty images discarded while keeping the annotated events:

  • at 100% : the model discards no valid event;
  • at 99% : we allow ourselves to miss 1% of valid events.

A wildlife monitoring project?

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