Predator odours attract other predators, creating an olfactory web of information

Abstract

Many studies have reported the aversive reactions of prey towards a predator's odour signals (e.g. urine marks), a behaviour widely thought to reduce the risk of predation by the predator. However, because odour signals persist in the environment, they are vulnerable to exploitation and eavesdropping by predators, prey and conspecifics. As such, scent patches created by one species might attract other species interested in information about their enemies. We studied this phenomenon by examining red fox investigation of odours from conspecifics and competing species in order to understand what prey are responding to when avoiding the odours of a predator. Surprisingly, foxes showed limited interest in conspecific odours but were highly interested in the odours of their competitors (wild dogs and feral cats), suggesting that odours are likely to play an important role in mediating competitive interactions. Importantly, our results identify that simple, dyadic interpretations of prey responses to a predator odour (i.e. cat odour ¼ risk of cat encounter ¼ fear of cats) can no longer be assumed in ecological or psychology research. Instead, interactions mediated by olfactory cues are more complex than previously thought and are likely to form a complicated olfactory web of interactions.

Exploiting interspecific olfactory communication to monitor predators

“…Odors deposited unintentionally, as an individual moves around in its environment, would attenuate quickly and their attractiveness would be superseded by fresher odor deposits. However, odor signals (scat, urine, or body odor) that are deposited intentionally, may persist for longer in the environment and these signals may create a web of information among sympatric predators (Banks et al 2016). Stoats were the only mesopredator recorded intentionally scent marking beside the ferret odor, both by body rubbing and defecating, which occurred during 21% of observations.…”

“…Further evidence highlighting the role of odor in mediating predator interactions was provided in a study on foxes ( Vulpes vulpes ), where urine from a dominant (dingo, Canis dingo ) and a subordinate predator (cat) were investigated with greater frequency than conspecific odor or a control (Banks et al. ).…”

“…Ferret body odor, which has evolved as a mechanism for communication (Clapperton and Byrom 2005), provoked the strongest attraction, suggesting that coevolution and/ or taxonomic relatedness may magnify responses. Further evidence highlighting the role of odor in mediating predator interactions was provided in a study on foxes (Vulpes vulpes), where urine from a dominant (dingo, Canis dingo) and a subordinate predator (cat) were investigated with greater frequency than conspecific odor or a control (Banks et al 2016).…”

Biologically meaningful scents: a framework for understanding predator–prey research across disciplines

“…This information not only shows current dominance, but due to the most stable molecules (MUPs) secreted in the urine, provides a record of past challenges to the dominant male (Hurst & Beynon, ). In the process, these bulletin boards also provide a record for heterospecifics to obtain information about their competitors and predators (Banks et al., ). Indeed, the volatile odour profile is an open broadcast system that could directly and indirectly influence communities and trophic networks (Hughes, Kelley & Banks, ; Jones et al., ).…”

“…These innovations have helped us to understand that scents may contain more specific information than was previously recognized. An olfactory secretion may provide information about an individual's age and social class (Osada et al, 2008), individual identity and genotype (Kerley & Salkina, 2007), health (Zala, Potts & Penn, 2004), disease status (Lanuza et al, 2014;Olsson et al, 2014), hunger level and diet (Wyatt, 2010) as well as additional information being conveyed from patterns of marking and overmarking (Banks, Daly & Bytheway, 2016). This information is available to conspecifics, as well as being potentially available to heterospecifics (Hughes, Korpimäki & Banks, 2010a;Hughes, Price & Banks, 2010b;Jones et al, 2016).…”