Giada Studer - Master thesis

Large predators naturally arouse both fear and fascination in humans.

The presence of wolves and their impact on cattle is controversially debated in Switzerland as in other countries worldwide. Recent political decisions sparked an intense public discussion.

In Switzerland there are three historical large carnivores: bear (Ursus arctos), lynx (Lynx lynx) and wolf (Canis lupus), all of which were extirpated from the territory between the 19th and 20th centuries by human persecution and habitat alteration.

In 1890 the last wolf was reported and killed by humans as it was considered a threat to livestock.

In 1995, more than a century later, the wolf naturally returned to Switzerland by migrating from Italy. Throughout the years, their range has extended and since 2021, we have been witnessing the annual emergence of new wolf packs.

At the same time, farmers have abandoned traditional husbandry methods causing greater exposure to predatory risk.

The current defensive strategies, employing guarding animals and various types of fencing -both electrified and non-electrified-, have demonstrated limited efficiency. Current attempts to foster coexistence between wolves and alpine agriculture have proven inadequate, resorting predominantly to selective culling . However, this approach is not a viable solution for species conservation -wolf is currently listed in the annex II of the Bern Convention as a strictly protected species- and has shown inefficacy in ensuring long-term livestock protection.

Bruns, A., Waltert, M., & Khorozyan, I. (2020). The effectiveness of livestock protection measures against wolves (Canis lupus) and implications for their co-existence with humans. Global Ecology and Conservation, 21

Lorand, C., Robert, A., Gastineau, A., Mihoub, J.-B., & Bessa-Gomes, C. (2022). Effectiveness of interventions for managing human-large carnivore conflicts worldwide: Scare them off, don’t remove them. Science of The Total Environment, 838, 156195

Non-lethal methods present a more functional and economically viable alternative, positively favoring predator-human interaction and the whole biodiversity

This project aims to explore an alternative approach, termed as a "biofence", leveraging carnivores' natural scent-marking behavior for territorial defense. Originating in Botswana, this method harnesses animals' instinctual avoidance of conflicts with neighboring conspecifics by establishing territorial boundaries.

Indeed, wolves predominantly utilize scent communication through urine, feces, and scratching to delineate territories, preventing territorial clashes.

By utilizing scent-marking substances strategically, this approach have the potential to create bio-boundaries, deterring wolves from encroaching on specific zones like livestock farms and urban areas.

My project in a nutshell!

Video produced by Prisca Grassi

The paper is out! Read it in Frontiers in Ethology

In a controlled study conducted across several Swiss wildlife parks, five packs were exposed to scent stations placed outside their enclosures, simulating the presence of an external intrusive conspecific through wolf urine.

Thirteen wolves were observed in total, including both breeders (adult wolves currently in a bonded, mixed-sex dyad with breeding potential) and non-breeders (wolves not belonging to a bonded pair, either due to their subordinate status within the pack or because they had lost a previously bonded mate, or because they had been neutered), and their behavioural responses were recorded continuously using camera traps. The experimental design allowed to compare reactions not only between wolf and human odours, but also across different breeding status within the pack.

The results show a clear pattern: breeding individuals — those responsible for reproduction and the cohesion of the pack — responded much more strongly to unfamiliar scent marks. They engaged significantly more in investigatory behaviours such as approach, sniffing, and over-marking, particularly when exposed to wolf urine compared to non-breeding individuals.

These findings highlight that scent marks are not neutral stimuli, they function as social information, interpreted flexibly depending on the receiver’s status, experience, and role within the group.

In the biofencing concept, the key challenge is not simply whether scent can trigger avoidance or attraction, but how do wolves react when interacting with an unfamiliar smell from a potential fatal rival. Understanding the underlying behavioural mechanisms allow to have the foundation to build deterrent measures such as biofencin. Any attempt to design olfactory barriers risks being ineffective or misleading.

Understanding how wolves interpret scent — and under which conditions these signals become meaningful — is therefore a necessary step before any applied use in conservation or conflict mitigation can be considered.

Canis lupus lupus

Marécottes Packs

First Pack

Breeding pair