NMBU tests capture-free GPS collaring: red deer and foxes fit tracking collars themselves
In a proof-of-concept study, red deer and red foxes in Norway fitted themselves with tracking collars at baited units, removing the need for capture.
Researchers at the Norwegian University of Life Sciences (NMBU) have demonstrated a way to deploy GPS collars on free-roaming terrestrial animals without capturing them, according to a EurekAlert release dated 4 November 2026. The proof-of-concept study, published in BioScience, describes Capture-Free Telemetry (CFT): tracking devices are placed on wild animals as they interact with baited deployment units in their natural habitat eurekalert.org
EurekAlerteurekalert.orgOpen source ↗. The system was invented by Prof. Richard Bischof, who is also the author of the study.
The problem with capture
Traditional wildlife telemetry relies on physical capture, which the release describes as invasive, difficult and expensive. Capturing and restraining animals can cause severe stress and carries risks of injury or death for animals, and sometimes for people eurekalert.org
EurekAlerteurekalert.orgOpen source ↗. Because capture is often the riskiest component, tracking studies frequently monitor only a handful of animals at a time, and design compromises are made to stretch collar battery life.
Bischof says that capturing and immobilizing animals affects their behavior, physiology and fitness, which can introduce bias into the data. He proposes what he calls "finer-touch telemetry": collaring more animals less invasively and tracking each for a shorter period. According to Bischof, this can give better coverage of the population and more detailed data, with less disturbance to natural behavior eurekalert.org
EurekAlerteurekalert.orgOpen source ↗.
Field trials and design
CFT uses species-specific autonomous deployment setups. In trials in Norway, Bischof demonstrated proof-of-concept systems for ungulates (red deer, Cervus elaphus) and carnivores (red foxes, Vulpes vulpes) eurekalert.org
EurekAlerteurekalert.orgOpen source ↗. The deer trials took place at the Norwegian Deer Centre (Norsk hjortesenter). The collars adjust automatically to the animal's neck size and are designed to drop off after a few weeks or a couple of months. They also have built-in weak spots that allow separation in case of discomfort or entanglement.
The idea builds on Bischof's earlier work as a wildlife biologist with the Nebraska Game and Parks Commission in the United States, where he worked with professional trappers and began to consider snare-based devices for marking animals without human handling. He later found largely forgotten studies from the 1950s to the 1970s on automatic animal marking. Snares are among the oldest trapping devices, but can be non-selective and harmful when misused, and poachers use them. Bischof notes the paradox that a controversial method may reduce the need to capture and handle animals for research.
Bischof and colleagues in Europe and the USA are now working to develop and test CFT further. They plan to compare its behavioral effects with those of capture-based telemetry and to explore its use for other species.
