Lynx urine improves selectivity of fox ingestion of baits

    A study reveals that lynx urine can be used as an attractant to enhance fox consumption of bait while minimizing consumption by other species. This advance can improve the cost-effectiveness in the application of baits for conditioned aversion, vaccination or camera trapping.


    The use of baits to reduce the incidence of diseases such as tuberculosis through vaccination, or to produce conditioned aversion in conflicts generated by predation, is widespread throughout the world. However, the programs for its application are often not successful enough due to the large number of baits that are consumed by non-target species, causing an increase in the number of baits to be used and consequently in the associated costs.

    Therefore, the use of baits requires new approaches to improve selectivity in application methods. In this sense, it is necessary to explore the possibility of using specific attractants to improve the intake of baits by target species while minimizing the intake by non-target species of baiting campaigns.

     

    The fattening of foxes has various applications in the field of managing their populations, including their vaccination, the generation of conditioned aversion to prey to reduce conflicts generated by predation, and camera trapping.

    Scientists from the Research Group in Game Resources and Wildlife Management and the Research Group in Wildlife Toxicology of the Instituto de Investigación en Recursos Cinegéticos (IREC – CSIC, UCLM, JCCM) have evaluated two attractants used in carnivore studies to improve the probability of bait intake by red foxes and minimize bait intake by non-target species.

    For that, Non-toxic baits were distributed throughout 1.000 ha and their intake was monitored for periods of 3 weeks using camera traps.. The baits were assigned to two treatments with odorous attractant (lynx urine and a mixture of fatty acids – FAS) and a control.

    The results showed that Adding lynx urine near the baits (1-2 m) significantly increased bait intake by foxes (58,8%) compared to control (5,7%) and FAS treatment (16,7 %). The intake of baits by non-target species was lower in the treatment with lynx urine (23,5%) than in the control (54,7%) and also with respect to the FAS (36,7%).

    The probability of persistence of the bait after the 3-week trial period differed significantly between treatments, being lower in the treatment with lynx urine than with FAS and the control. All baits consumed by foxes with the lynx urine treatment (58,8%) occurred within the first 10 days, whereas ingestion by non-target species (23,5%) stopped after day 7.

     

    Lynx urine improved bait intake by foxes (a) and reduced bait consumption by non-target species (b).

    By using odorous attractants such as lynx urine, the proportion of baits consumed by foxes is increased while minimizing the amount of bait available to non-target species.. On the other hand, the persistence time of baits in the environment can also be reduced, thus minimizing the risk of bait consumption by non-target species and reducing application costs. Therefore, lynx urine or other odorous attractants can be used to optimize baiting methods for foxes in their different applications, such as studies of conditioned aversion, vaccination or photo-trapping.

    The scientific publication of this research is available at: