A Nose for Death: Integrating Trophic and Informational Networks for Conservation and Management

Abstract

Non-lethal management of wildlife, both "problem wildlife" and pest species, to protect crops and threatened species is becoming increasingly important as non-human animals and humans come into closer proximity. A particularly promising approach is to apply predator scents to manipulate the cost/benefit ratio that influences the behavioral decisions made by prey and other predators about where to forage or rest. However, such olfactory manipulations are not always successful. Using insights from size-structured food webs, we develop a novel integrative model of the information that animals acquire from eavesdropping on predator and conspecific scents. We show how animals can use the information content in predator scents to derive knowledge of other predators and competitors and thus influence their decision to stay in or leave an area. This model framework clarifies how predator scents can influence all trophic levels, from interference competition directed at smaller predators, to predation and herbivory, and exploits direct and indirect pathways to promote landscapes of fear that influence spatial and temporal patch use in target animals. We illustrate how the application of this conceptual model can focus future research to enhance the use of predator scent-based deterrents in conservation and management. This integrated model shows great promise for addressing wildlife management concerns and for eventually improving the success and efficacy of traditional management techniques.

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

“…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., ).…”

“…This temporal component explains why terrestrial animals, from mice (Garratt et al., ) to white rhinoceroses ( Ceratotherium simum ; Owen‐Smith, ), invest so much time and energy marking and remarking and saturating their walkways while they defend a territory. Both conspecifics (Garratt et al., ) and heterospecifics (Jones et al., ) may respond to these marks when present and when marks are no longer refreshed. Understanding the potential meaning of this is essential for planning experiments and deploying scent‐based tools.…”

“…Indeed, Jones et al . () showed how scents (both their presence and absence) are embedded within information networks, and thus serve indirectly as both attractants and deterrents to other species in the food web.…”

“…One hypothesis is that faded scents may provide information that the signaller is absent (Hurst & Beynon, 2004). Indeed, Jones et al (2016) showed how scents (both their presence and absence) are embedded within information networks, and thus serve indirectly as both attractants and deterrents to other species in the food web.…”

“…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).…”