Influence of gaze and directness of approach on the escape responses of the Indian rock lizard, Psammophilus dorsalis (Gray, 1831)

Abstract

Animals often evaluate the degree of risk posed by a predator and respond accordingly. Since many predators orient their eyes towards prey while attacking, predator gaze and directness of approach could serve as conspicuous indicators of risk to prey. The ability to perceive these cues and discriminate between high and low predation risk should benefit prey species through both higher survival and decreased energy expenditure. We experimentally examined whether Indian rock lizards (Psammophilus dorsalis) can perceive these two indicators of predation risk by measuring the variation in their fleeing behaviour in response to type of gaze and approach by a human predator. Overall, we found that the gaze and approach of the predator influenced flight initiation distance, which also varied with attributes of the prey (i.e. size/sex and tail-raise behaviour). Flight initiation distance (FID) was 43 percent longer during direct approaches with direct gaze compared with tangential approaches with averted gaze. In further, exploratory, analyses, we found that FID was 23 percent shorter for adult male lizards than for female or young male (FYM) lizards. In addition, FYM lizards that showed a tail-raise display during approach had a 71 percent longer FID than those that did not. Our results suggest that multiple factors influence the decision to flee in animals. Further studies are needed to test the generality of these factors and to investigate the proximate mechanisms underlying flight decisions.

Human habituation reduces hyrax flight initiation distance in Serengeti

“…Ydenberg and Dill () predicted that FID increases with increasing distance to refuges and this model has been supported in several studies (Bonenfant & Kramer, ; Cooper Jr., ; Gotanda, Turgeon, & Kramer, ; Kramer & Bonenfant, ). Other variables that could affect FID are position between approaching predator and prey's refuge (Kramer & Bonenfant, ), eye contact, patch quality for feeding animals and temperature (Cooper Jr., ; Fernández‐Juricic, Jimenez, & Lucas, ; Sreekar & Quader, ). Taking one or more of these variables into consideration would probably help explain more of the variation in FID.…”

Flight Initiation Distance as Behavioral Indicator of Hunting Pressure: A Case Study of the Sooty-Headed Bulbul (Pycnonotus Aurigaster) in Xishuangbanna, SW China

“…We did not measure the FID of these mistrials. Each trial involved walking directly towards the selected bird flock from the starting point, with gaze oriented directly towards the subject flock, as orientation and approach are conspicuous cues of predation risk [7,20]. The approach towards the flock was always in a straight line, with no vegetation preventing the observer and bird flock from seeing one another.…”

“…Flight initiation distance (FID) is the distance between the prey and the predator or hunter at the point when an animal begins to flee. If the prey behaves optimally, one would expect the FID to increase with predation or hunting pressure [6,7]. For example, FIDs of fishes, ungulates and birds to humans were higher in areas with hunting than in areas without hunting [8][9][10][11][12][13][14][15].…”

“…In an environment with at least some predation or hunting pressure, individuals that flee too late are more likely to be killed, whereas individuals that flee too soon unnecessarily increase energy expenditure through locomotion, potentially reducing food intake and social activity. For these reasons, individuals should optimize their FID by weighing the risk of predation against the costs of flight [6,7].…”

Gaze following in an asocial reptile (Eublepharis macularius)

“…Although leopard geckos are solitary, they can be housed together in captivity. Squamates show visual sensitivity in relation to predation risk, actively averting their gaze when approached and stared at by a human ‘predator’ coming directly toward them but not exhibiting this behaviour when approached diagonally (Burger et al 1992 ; Elmasri et al 2012 ; Sreekar and Quader 2013 ). Siviter et al ( 2017 ) recently showed that bearded dragons ( Pongo vitticeps ) are able to follow the gaze of another individual around a barrier into distant space.…”