Geese recognize each other in the photo

Anyone walking through the Austrian Almtal two years ago might have encountered something wonderful: knee-high billboards with life-size photos of geese. Children’s party? Art project?

No, it was an experiment by the Konrad Lorenz Research Center for Behavior and Cognition. The question was whether gray geese can recognize each other by sight. Do they show more friendly behavior toward a photo of their partner than toward control photos? Yes, was the clear answer. Greylag geese thus demonstrate a higher cognitive ability that until now had only been demonstrated in mammals. The Austrians write this this month in the Journal of Ornithology.

Recognizing individuals is important for social, long-lived species. This skill helps, for example, in caring for family members, in cooperation, in conflict avoidance and in forming alliances. Many animals use smells and sounds to recognize each other. For example, birds and sea lions recognize their young by their squeaking; dolphins even each have their own vocal ‘signature’. But sight also plays a role in recognition. This has so far mainly been demonstrated in primatesbee sea ​​lions and even in sheep – but never before in birds.

Greylag geese can live up to 25 years and mates stay together for life. The idea that they visually recognize each other is half a century old. It comes from the Austrian biologist and Nobel Prize winner Konrad Lorenz (1903-1989), founder of behavioral biology and namesake of the institute in the Almtal. Lorenz studied the social behavior of gray geese in great detail. He was soon able to recognize ‘his’ geese by their appearance. This made him suspect that the geese themselves also use this characteristic.

Beak recognition

The authors of the recent study now tested that idea in several ways. First they looked at whether goose faces provide enough clues for recognition. To this end, they developed an app for beak recognition. They trained software based on thousands of photos of a group of wild gray geese that have been fed in the Almtal since the times of Lorenz. That app turned out to be successful – and the beaks a good, consistent identification feature. The app recognized 98 percent of the birds; a year later still 97 percent.

Then it was time for field tests. The researchers covered boards with full-size photos of various geese from the ‘Lorenz group’. They placed feeders just in front of the signs, and cameras at some distance to record which geese came to forage, how quickly and how close they approached the signs, how long they stayed there and what behavior they showed. The geese were individually recognizable to the researchers by color rings on their legs; All family relationships of the entire group had been kept track of for fifty years.

Strange goose

The geese probably use a combination of features for visual recognition, the researchers suspect. In addition to the beaks, perhaps also faces, feather patterns, or perhaps even the color rings. In each case, the geese showed significantly different behavior towards different plates, in order of increasing friendliness: empty plates, a strange goose, a group member and their own partner. For example, they approached their partner’s photo up to twice as fast, foraged for up to three times as long and made up to ten times as many ‘contact sounds’.

“Our findings add to the considerable previous evidence that geese possess relatively advanced cognitive skills,” the Austrians conclude. They think their new app can help with future geese research, including in citizen scienceprojects, for example censuses.