Potential risks of olfactory signaling: the effect of predators on scent marking by beavers

Mammals scent mark their territories to advertise occupancy and ownership. However, signaling with scent for territorial defense can have a negative effect by advertising an individual’s presence and location to predators. In this study, we measured responses to a simulated territorial intrusion by...

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Bibliographic Details
Main Authors: Frank Rosella, Jørn Ingar S
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
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Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.576.9055
http://beheco.oxfordjournals.org/content/17/6/897.full.pdf
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Summary:Mammals scent mark their territories to advertise occupancy and ownership. However, signaling with scent for territorial defense can have a negative effect by advertising an individual’s presence and location to predators. In this study, we measured responses to a simulated territorial intrusion by conspecific adult male Eurasian beavers (Castor fiber) either in the localized presence or in the absence of odor of a predator to test the hypothesis that the territorial defense of free-living beavers would be disrupted by the presence of predation risk in their natural environment. We predicted that beavers would significantly reduce their willing-ness to countermark intruder’s scent in the presence of the scent of predators (wolf [Canis lupus] and lynx [Lynx lynx]), com-pared with a control (no odor), as responses are in general stronger to predator scent marks than nonpredator scent. Therefore, we also predicted that the effects of nonpredatory mammal scent (neophobic control) (eland [Taurotragus oryx] and horse [Equus cabalus]) are to be expected somewhere in between the effects of the predator odor and a control. Our results suggest that both predator and nonpredator scents reduce beavers response to a simulated intruder’s scent mounds and therefore disrupt their territorial defense. However, predator scent had a stronger effect than nonpredator scent. Beavers may therefore be at great risk on territories with predators present because of the trade-off between predator avoidance and territorial defense. Our study demonstrates the potential of predation risk as a powerful agent of counterselection on olfactory signaling behavior. Key words: Castor fiber, chemical communication, predation risk, scent marking, signals, territorial. [Behav Ecol 17:897–904 (2006)] Territories allow their owners exclusive access to criticallylimiting resources and are thus, in territorial species, an es-