Skip to content

Vanilla–Capsaicin Pairing Delayed Red Fox Bait Consumption but Did Not Reduce Overall Intake

Juvenile red fox in Tablas de Daimiel National Park, Ciudad Real, Spain
Research · Behaviour

A field experiment published in 2026 tested whether red foxes (Vulpes vulpes) could associate a neutral odour with an unpleasant repellent and subsequently alter their feeding behaviour. Baits paired with vanilla odour and capsaicin took longer for foxes to consume, and the delayed response persisted in later phases when vanilla was presented without capsaicin. Overall bait consumption, however, did not clearly differ between treatments or experimental phases.

The study was conducted in Sierra de Picón in Ciudad Real province, central Spain, using eight baiting points divided between treatment and control sites. The experiment moved through four phases: a pre-repellency phase without treatment, a repellency phase with capsaicin and vanilla at treatment points, a post-repellency phase with vanilla alone, and a final phase in which treatment and control locations were switched while vanilla was maintained at the new treatment points.

Vanilla delayed bait consumption but did not reduce intake

Researchers deployed 226 baits. Mammals or birds consumed 159 of them, and red foxes were the most frequent consumers, taking 110 baits. Foxes took longer to consume baits at treatment points during the repellency, post-repellency and post-repellency-rotation phases.

Graph of red fox bait consumption time across control and treatment phases with capsaicin and vanilla
Mean bait-consumption time for red foxes across control and treatment points and the four experimental phases. Figure 4 from Del Río et al. (2026), European Journal of Wildlife Research, CC BY 4.0.

Capsaicin produced clear aversive reactions

Responses associated with capsaicin included rubbing, scratching and salivation. Scratching was also recorded after capsaicin had been removed and only vanilla remained. Together with the longer delay before eating, this suggests that some foxes may have associated the vanilla odour with the earlier unpleasant experience, but the response was not strong enough to prevent bait consumption. The authors stress that this was a small pilot study with only eight baiting points and probably only a few individual foxes exposed to the treatments.

Sources and image credit

  1. Del Río, L., Zearra, J. A., Tobajas, J., Ferreras, P., & Mateo, R. (2026). An artificial odour associated with a repellent as a novel wildlife management: a pilot study. European Journal of Wildlife Research, 72, 38. https://doi.org/10.1007/s10344-026-02061-3Primary open-access research article published 28 February 2026 under CC BY 4.0. In a field experiment at eight baiting points in Sierra de Picón, Ciudad Real, 226 baits were deployed and red foxes consumed 110 (48.68%). Overall bait consumption did not differ significantly between treatments or phases, but foxes took significantly longer to consume treatment baits during the repellency, post-repellency and post-repellency-rotation phases. Spice-related responses also persisted when only vanilla odour remained.

Image: diego_cue — juvenile red fox (Vulpes vulpes) in Tablas de Daimiel National Park, Ciudad Real, Spain, photographed 1 May 2012; Wikimedia Commons / Panoramio; cropped to 16:9; representative photograph from the same province as the field experiment, not a fox recorded in the study · CC BY-SA 3.0 · Source

About this content: This story was produced with AI assistance within an editorial workflow developed by Wildlife Vagabond. Editorial responsibility remains with Wildlife Vagabond.How AI is used

Behaviour

SPECIES IN THIS STORY

Species in this story

Red Fox Vulpes vulpes Explore species

Independent research and conservation news archive

Did you find this information useful?

Wildlife Vagabond is independently built and maintained. Voluntary support helps cover source verification, hosting and continued work on research and conservation news.

Support Wildlife Vagabond

The news archive will remain freely available.