Source code and project files, including models, mm-wave radar drivers, and Max/MSP file for music generation: https://github.com/Jerry744/halfmind-flow

Try out TOVA test online. All data are saved locally in the browser: https://www.halfmind.nl

This report highlights the steps taken to design a foraging device that engages captive ring-tailed lemurs in a natural way. After identifying the stakeholders and their requirement, research into ringtailed lemurs’ natural and captive situation is done with the goal of identifying opportunities for design to enhance the lemurs’ welfare in captivity. At the same time, it also aims to improve zoo visitors experience.

As a result, a design is introduced that focuses on purposeful locomotion to increase activity, promoting different foraging interactions, stimulating multiple senses, and giving the animals a choice on when and how to interact. At the same time, it is shaped to look like a fruit these animals would eat in nature, and its placement increases the time lemurs spend close to the visitors

Multiple rounds of prototyping and tests with the ring-tailed lemurs in Rotterdam Zoo have been done to refine the concept and to assess its effectiveness. These test results seem promising, as lemurs interacted many times with the prototypes. The effectiveness of the final designed system and its long-term efficacy needs to be assessed in the future.

The final design consists of multiple wirelessly (un)lockable pods filled with food and connected to a scent machine. A number of these are unlocked at a time and a scent cue is given, prompting the lemurs to go investigate. Unlocked pods stay attached to their base using magnets, thus lemurs need to interact with both locked and unlocked pods to figure out which can be detached. This feeding system is an addition to the lemurs’ normal feeding regiment, as a result they are stimulated and engaged more than before.

► Introduction & Client | Over the last decade, there has been a notable increase of interest in discussions surrounding animal welfare, driven by a deeper understanding of the mental states of animals. This growing awareness has triggered a global push to improve laws and regulations in animal welfare, prompting zoos worldwide to increase their efforts in enhancing the quality of life for their captive animals.

Environmental enrichment has emerged as a crucial tool in increasing animal welfare, supported by studies showcasing its positive impact on reducing aggression and abnormal behaviour in captive animals. ARTIS Zoo actively applies environmental enrichment into its practices and collaborates with the University of Amsterdam to delve deeper into the behaviour and needs of their animals. Scientific research at ARTIS Zoo includes an ongoing exploration into whether primates can recognize time intervals.

► Project Scope | In an effort to further enhance the lives of their animals, ARTIS Zoo has joined forces with the faculty of Industrial Design Engineering of TU Delft to design a versatile device serving as both an enrichment tool and a research device. The project focusses on designing a feeding solution that mimics the natural foraging behaviour of the yellow cheeked gibbon and black crested macaque, taking into account both physical behaviour as well as cognitive abilities.

► Literature research | Literature research has delved deeper into animal welfare, environmental enrichment, and primate behaviour, resulting into important insights. Primates can forage efficiently because of their physical advantages over other animals while also using the WWW-memory (What, where and when). Primates use synchrony, temperature, solar cues and sensory cues to locate ripe fruit. Yellow cheeked gibbons forage in the high trees for fruit, while black crested macaques forage mostly on the ground between bushes and grass.

A vision has been shaped: The product should give the primates more autonomy over their feeding process while triggering the cognitive memory, decision making and problem solving abilities.

► Requirements | The design considerations for the device were carefully outlined, addressing the distinct needs of stakeholders:

Primate Usage: Concentrated on promoting foraging behaviour to reduce inactive periods.

Zookeeper Usage: Prioritizing a user-friendly design to maximize usability.

Researcher Usage: Enabling dual-purpose functionality for both enrichment and research, with remote control capabilities.

Safety Considerations: Ensuring material, assembly, and food safety through detailed specifications.

► Design | The final design (Figure 1.1) takes the form of a fruit, which needs to be peeled by primates to reveal food inside. The device closes automatically and can be locked and unlocked remotely. Iterative design improvements enhance user usability, material sturdiness, and food safety.

► User testing | User testing with gibbons at ARTIS Zoo showcases significant interest and interaction, supported by observational data indicating heightened engagement between gibbons, increased foraging activities, social behaviour and extended active periods in the presence of the device.