The Effects of Predator Odors in Mammalian Prey Species: A Review of Field and Laboratory Studies

Tierphysiologie, Zoologisches Institut, Universität Tübingen, Auf der Morgenstelle 28, D-72076 Tübingen, Germany.
Neuroscience & Biobehavioral Reviews (Impact Factor: 8.8). 02/2005; 29(8):1123-44. DOI: 10.1016/j.neubiorev.2005.05.005
Source: PubMed


Prey species show specific adaptations that allow recognition, avoidance and defense against predators. For many mammalian species this includes sensitivity towards predator-derived odors. The typical sources of such odors include predator skin and fur, urine, feces and anal gland secretions. Avoidance of predator odors has been observed in many mammalian prey species including rats, mice, voles, deer, rabbits, gophers, hedgehogs, possums and sheep. Field and laboratory studies show that predator odors have distinctive behavioral effects which include (1) inhibition of activity, (2) suppression of non-defensive behaviors such as foraging, feeding and grooming, and (3) shifts to habitats or secure locations where such odors are not present. The repellent effect of predator odors in the field may sometimes be of practical use in the protection of crops and natural resources, although not all attempts at this have been successful. The failure of some studies to obtain repellent effects with predator odors may relate to (1) mismatches between the predator odors and prey species employed, (2) strain and individual differences in sensitivity to predator odors, and (3) the use of predator odors that have low efficacy. In this regard, a small number of recent studies have suggested that skin and fur-derived predator odors may have a more profound lasting effect on prey species than those derived from urine or feces. Predator odors can have powerful effects on the endocrine system including a suppression of testosterone and increased levels of stress hormones such as corticosterone and ACTH. Inhibitory effects of predator odors on reproductive behavior have been demonstrated, and these are particularly prevalent in female rodent species. Pregnant female rodents exposed to predator odors may give birth to smaller litters while exposure to predator odors during early life can hinder normal development. Recent research is starting to uncover the neural circuitry activated by predator odors, leading to hypotheses about how such activation leads to observable effects on reproduction, foraging and feeding.

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    • "However, the behavioral response of rodents to deterrent (plant) odors other than direct application to the food source has rarely been investigated. A large body of literature confirms that small mammalian species which are exposed to predator odors show alterations in foraging, feeding, general activity, and reproduction, especially in females (Apfelbach et al. 2005; Tran and Hinds 2012). However, males will also be affected by repellents and they also play an important role for rodent infestations. "
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    ABSTRACT: Rodents are among the most damaging pests in agriculture worldwide. High-density populations of rodent pests can kill plants or diminish their growth, and reduce both fruit size and the number of seeds. Therefore, rodent pests can lead to considerable crop loss and require management actions to minimize damage. Optimal management of pest rodents is usually based on the combination of methods to reduce damage. Although rodenticides are usually the most commonly deployed approach, they have undesirable side effects. Consequently, more environmentally benign approaches such as repellents or attractants to lure rodents away from fields are gaining traction. The dispersal of a large number of juvenile males at certain times of year has prompted us to focus on male rodents for our experiments. We used laboratory feeding experiments to measure how the odor of plant secondary metabolites (PSMs) affects two pest rodents: common voles (Microtus arvalis, Pallas) and house mice (Mus musculus, L.). We tested eighteen different PSMs or combinations thereof with voles. Four PSMs reduced feeding and seven PSMs increased feeding of male common voles. Five of six tested odors were effective as repellents against house mice. However, we assume a species-specific response to volatile PSMs repellents. This study demonstrated that four repellents reduced feeding in both rodent species. Our results contribute to the development of non-lethal management tools for rodent pest species that are potentially more suitable than traps and rodenticides. This approach could be applicable to a variety of crops if effective at field conditions.
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    • "tone ) and repellent taste ( e . g . bitter tasting compounds like tannins and phenols ) could be combined to minimize possible habituation of rodents to the repellent odor , because post - ingestive effects are induced . Otherwise animals could adapt to repellents by recognizing that the odor is not con - nected to a negative or positive reward . Apfelbach et al . ( 2005 ) reviewed the effects of predator odors as repellents for mamma - lian prey and observed significant habituation . We could observe that in some treatments ( e . g . BPO 2% or abetic acid ) the deterrent effect seemed to decline in the four days of the trial based on increasing food consumption . However , we could demonstrate that fema"
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    ABSTRACT: Rodents can cause extensive damage in agricultural systems. This results in considerable harvest loss as well as damage to agricultural infrastructure. To prevent this, the use of rodenticides has increased worldwide. Rodenticides not only affect rodent pest species but also harm non-target species such as predators and other small mammals. In this paper we show how the odor of plant secondary metabolites (PSMs) can affect the feeding behavior of two rodent species: the common vole (Microtus arvalis, Pallas) and house mouse (Mus musculus, L.). Common voles are a major vertebrate pest species in agriculture whereas house mice are commensal pests. Both species are well-known to cause severe damage to diverse agricultural enterprises in Europe. We conducted laboratory feeding experiments initially with females because their fitness depends more on their foraging behavior than it does in males. We tested a range of volatile PSMs on voles initially and those compounds that proved effective were later tested on the house mice. Out of 13 PSMs or combinations of PSMs, nine reduced the amount of food eaten and one (bucco oil) increased feeding by voles. In house mice we identified six deterrent PSMs which reduced the food intake including bucco oil and there were two compounds that had no effect on feeding. Those metabolites that were repellent should be tested in field trials for their efficacy and may be suitable alternatives to rodenticides.
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    • "In order to investigate and understand antipredator behaviors, we need to make detailed observations in a simulated environment (Dielenberg and McGregor 1999; Blanchard et al. 2003). The use of a " microworld " simulation enables the identification of decreases in locomotor activity, reductions in nondefensive behaviors such as grooming and reproduction, and retreat to a strategic location if prey detect a predator (Apfelbach et al. 2005). Such simulations are useful because they detect behaviors that cannot be identified or measured using field studies alone. "
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    Full-text · Article · Sep 2015 · Journal of Mammalogy
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