Animals in zoos are often plagued by boredom. This invention by TU Delft, designed to help them forage for food, helps to combat this.

Eureka is the section on ‘product designs for tomorrow’ in De Ingenieur.

The ring-tailed lemur lives in the forests of Madagascar. It eats leaves and fruit that it finds by following their scent. Its cousins at the zoo have it easier; they simply wait for the keeper to bring them their food. That sounds nice, but it disrupts their natural behaviour and increases boredom.

As part of his final-year project for the Master’s programme in Integrated Product Design at Delft University of Technology, Joshua de Ruijter developed a new feeding system for the ring-tailed lemurs at Blijdorp Zoo in Rotterdam. It consists of 3D-printed, hollow fruits suspended in the trees of the enclosure. The food is contained within the hollows.

The artificial fruits are sealed with magnets but can be opened using an app – and, in the final design, according to a pre-set schedule. By doing this for different individuals at different times of the day, the animals remain engaged and alert.

As soon as the fruits split open, the scent of ripe fruit fills the enclosure. The ring-tailed lemurs then have to work out for themselves which fruits these are. The idea is that this stimulates the animals at different times and through different senses, making the process of foraging more similar to how it happens in the wild.

De Ruijter’s invention improves animal welfare without creating too much extra work for the keepers. Blijdorp plans to renovate the ring-tailed lemur enclosure soon, says De Ruijter. ‘They will then integrate this system into the enclosure.’ He believes that such systems could also be useful for other animal species.


Photo: Joshua de Ruijter