When to Run and When to Hide: The Influence of Concealment, Visibility, and Proximity to Refugia on Perceptions of Risk

Abstract

An animal's ability to avoid predation likely depends on its ability to detect approaching predators, conceal itself, and seek refuge or protection from predators. Habitat, especially vegetation structure, can influence all of these factors concurrently. Binary categorical assessments of habitat as ‘open’ or ‘closed’, however, confound at least two functions of habitat structure that could influence the perceived risk of predation: concealment, which functions to hide an individual, and visibility, which enhances detection of a potential predator. Both can influence predation risk independently and simultaneously. In this study, we decoupled these functional properties of vegetation and studied the effects of concealment, visibility, and proximity to a refuge on the distance at which pygmy rabbits (Brachylagus idahoensis) fled from an approaching threat (flight initiation distance; FID). Concealment by vegetation decreased perceptions of risk; however, pygmy rabbits exhibited elevated risk at high levels of visibility, regardless of the amount of concealment. Proximity to burrow entrances also influenced perceptions of risk, such that risk was significantly lower when rabbits were on or near burrow systems. Disentangling the functional properties of habitat can provide a more comprehensive understanding of the factors that influence perceived risk and escape behaviors of prey and provide insight into how habitat structure mechanistically relates to predation risk.

Examining functional components of cover: the relationship between concealment and visibility in shrub‐steppe habitat

“…Variation in hunting modes among predators presents different types of threats to prey species and can select for different antipredator responses (Arnez andLeger 1997, Embar et al 2011). The habitat v www.esajournals.org selection that we documented was likely more representative of a response to a terrestrial threat (Camp et al 2012).…”

Prey refuges as predator hotspots: ocelot (Leopardus pardalis) attraction to agouti (Dasyprocta punctata) dens

“…This could imply that staying close to a refuge while active is not necessarily an effective antipredator strategy. Although the presence of a refuge may diminish predation risk by offering a quick escape route (Kramer and Bonenfant 1997;Camp et al 2012), this advantage holds only if prey can timely detect the predator and flee. The careful stalking behavior of the ocelot (Emmons 1988;Sunquist and Sunquist 2002), in combination with the typical dense cover provided by its forest habitat (Sunquist and Sunquist 2002; WJ Emsens personal observation), suggests a b Fig.…”

“…Moreover, many prey species use refuges to minimize exposure to predators while resting or to retreat to safety while active. It is generally assumed that staying close to a refuge is an effective antipredator strategy (Kramer and Bonenfant 1997;Camp et al 2012). By staying near a refuge, prey need less time to reach protection when a predator is encountered (Blumstein 1998;Camp et al 2012) and thus only stray from the vicinity of refuges for critical activities such as foraging or mating (Kramer and Bonenfant 1997).…”

Quantifying the Impacts of a Novel Predator: The Distinctive Case of the Oregon Spotted Frog (Rana pretiosa) and the Invasive American Bullfrog (Rana (Aquarana) catesbeiana)

“…However, the highly cryptic litterdwelling frogs in the genus Craugastor exhibit behavior that is clearly more extreme; >90% of individuals approached by a human observer did not flee until touched (Cooper et al 2008). Further, where degree of crypsis has been quantified, more cryptic taxa or individuals generally have shorter flight initiation distances (Heatwole 1968;Cooper and Sherbrooke 2010;Camp et al 2012). Hence, the longer flight initiation distances of R.…”