Rats Are Invasive Menaces. These Cameras Spy on Them

Climate change, pollution, and overfishing are just some of the troubles off the coast of southern California. The Nature Conservancy launched a campaign of eradication after it was discovered that Santa Cruz Island once had pigs and Argentine ants. The island fox was on the verge of extinction.

The Nature Conservancy now has to defend against rats because the battle was won but the war wasn't over. Rats eat native plant seeds, bird and reptile eggs, and local people's crops when they land on islands. Manhattan is one of the urban islands of steel and concrete. It's hard to get rid of them once they're established. They had to use poison-dropping drones to destroy them on the Galpagos Island.

On Santa Cruz Island, the Nature Conservancy uses a network of wildlife camera traps and artificial intelligence to learn if rats have landed. While scientists have been using various forms of the camera trap for a hundred years, this version automatically detect when a mouse comes into view, and sends an email alert to the people who care about the animals. Nathaniel Rindlaub is a software developer at the Nature Conservancy who is leading the project.

Santa Cruz Island needed this innovation to succeed. Biologists usually have to revisit their camera traps every few months to get the memory card and swap the battery. It can also mean hiking into a rainforest or around a rock that is three times the size of Manhattan. By the time you get to your camera, the rat might have been there for months.

There is a chance that a deer or bear will knock your camera over. A blade of grass whipping back and forth in front of the lens could make it fire off a bunch of pictures very quickly. The camera could take thousands of pictures. Saul Greenberg, who developed image recognition for camera traps but wasn't involved in this new work, said that up to 90 or 95 percent of images may have nothing in them. Don't pay attention to recognition. A lot of people use camera traps if you can tell them that the images are empty.

In nearly real time, Rindlaub's system works to remove images. The cameras are powered by solar energy. One can take a picture and send it to another camera in the chain, which will send it to a base station connected to the internet. The image is uploaded to the internet.

Rindlaub says that images get piped through a sequence of computer vision models that attempt to determine what is in them. The animals are trained to differentiate between them. It can only look for rodents in general, as it can't tell the difference between native and non-native animals. It fires off an email to Rindlaub and his colleagues when it sees something that isn't normal. No rats have been found on Santa Cruz Island.