Department of Physics, Chemistry and Biology (IFM)

Mammalian prey species have evolved various sensory and behavioral adaptations in order to avoid predators. Among these adaptations is the ability to detect predator-related odors and to display appropriate defensive behavior. However, there is limited knowledge about whether blood odors are sufficient to elicit such behavior. Therefore, I assessed if predator-naive CD-1 mice (n=60) avoid blood odors from conspecifics (male and female) as well as non-predator (horse and human) and predator species (cat), and/or display other indicators of anxiety-like behavior. Additionally, I assessed whether mice avoid a volatile substance found in mammalian blood (trans-4,5-epoxy-(E)-2-decenal), as well as a fruity odorant (n-pentyl acetate). A two-compartment test arena was used to assess approach/avoidance behavior, general motor activity and the number of fecal pellets excreted. The animals were presented with a blood odor in one compartment and a blank control in the other compartment. All of the blood odors were significantly avoided by the mice. The mice also spent significantly less time in the compartment with the blood odor component (trans-4,5-epoxy-(E)-2-decenal) compared to the blank control. The fruity odorant was not significantly avoided. There was no significant difference between the odors with regard to general motor activity or the number of excreted fecal pellets, both widely used measures of stress- or fear-related behavior. The results of the present study support the notion that the perception of blood odors is important in predator-prey interactions. Likewise, the blood odor component may be an important characteristic of mammalian blood with regard to odor signaling.