A novel non-permanent attachment method for bird-borne tracking devices using 3D-printed clamps

Abstract Collecting GPS positions on bird movements requires secure and efficient attachment methods that maintain animal welfare. For seabirds, one of the most threatened bird groups globally, non-permanent attachment methods are often preferred in short-term studies due to their lower risk of injury, feather damage, or long-term behavioral disruption. However, most available non-permanent solutions, such as tape or temporary adhesives, fail to stay attached for extended periods, often resulting in device loss within days or weeks. Here, we present a novel 3D-printed clamp design for attaching small solar-powered GPS devices to seabirds. The clamp and device were attached to the bird's feathers using only glue, with the clamp specifically designed to interlock with the device. This interlocking mechanism effectively sandwiches the feathers between the clamp and the device, ensuring a secure connection through the use of glue. The clamps were designed to maximize solar panel exposure and minimize premature detachment. We deployed 86 GPS devices on six seabird species across seven locations in Norway from 2023 to 2024, using device-specific clamp variants for attachment to mantle or tail feathers. Devices remained attached for an average of 39 days on mantle feathers (77 birds) and 77 days on tail feathers (four birds), providing sufficient deployment durations to monitor key life stages, such as incubation and chick-rearing. The weight of the clamp structure ranged from 0.5 to 3.2 g, depending on the variant, and emphasis was placed on keeping the total attachment weight as low as possible. The clamps were low-cost, easy to produce using standard 3D printers, and allowed adjustments during application. Our method offers a practical alternative to conventional glue or tape mounts, enabling longer device retention, optimal solar charging, and improved data recovery without resorting to permanent attachment methods such as harnesses. It is particularly well suited for short-term tracking applications over a few weeks to months, such as studying foraging behavior, molt timing, or seasonal movements. Overall, the clamp-based attachment system offers a practical and reliable method for short-term seabird tracking, improving data quality while minimizing impact on the birds.