Lateralisation of predator avoidance responses in three species of toads

Abstract

Lateralisation of responses to presentation of a simulated predator was investigated in three species of toads: two European species (the common toad, Bufo bufo, and the green toad, Bufo viridis) and one species introduced to Australia from South America, the cane toad Bufo marinus . First a simulated snake was presented moving rapidly towards the toad in the frontal field of vision and the toad's escape responses, including jumps to the right and to the left, were recorded. No significant bias in left or right side jumping was apparent in this test. Next the simulated snake was presented in the left or right lateral field of vision in random order. Escape and defensive responses were elicited more strongly, in all three species, when the stimulus was on the toad's left side compared to its right side. Reaction times scored in the experiments with B. marinus, alone, did not differ from left to right. There were, however, species differences in the types of escape responses with respect to the laterality: B. viridis and B. marinus showed similar patterns of more sideways jumps with left presentation and more frontal jumps with right presentation. Sideways jumps were not lateralised in B. bufo, but this species showed more frontal jumps when the presentation was on the left side. These findings suggest that the selective involvement of structures located in the right side of the brain (left monocular visual field) in emotional responses (particularly fear responses) could be a phylogenetic ancient trait.

The costs of hemispheric specialization in a fish

“…The literature contains many other examples of remarkable left -right differences in the behavioural response. For example, toads, chicks and dunnarts differ in their promptness to react to a predator depending on the visual hemifield in which it appears (Lippolis et al 2002(Lippolis et al , 2005Dharmaretnam & Rogers 2005), and mosquitofish make closer cooperative predator inspection when predator and shoalmates are seen with the correspondingly preferred eye (De Santi et al 2001). Gelada baboons and Anolis lizards are more likely to attack a conspecific on one side than the other (Deckel 1995;Casperd & Dunbar 1996), and side biases are shown by toads, chicks and pigeons in food detection (Vallortigara et al 1998;Diekamp et al 2005).…”

Social environment elicits lateralized behaviors in gorillas (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes).

“…These responses may be driven by a left eye dominance to control aggressive behaviors. Several vertebrate species, such as birds (Franklin III & Lima, 2001;Koboroff, Kaplan, & Rogers, 2008;Rogers, 2000b), lizards (in the laboratory: Bonati, Csermely, & Sovrano, 2013;in the wild: Martín, López, Bonati, & Csermely, 2010), and toads (Lippolis, Bisazza, Rogers, & Vallortigara, 2002), manifest a left eye preference in monitoring a predator and a rightward preference for escaping from the dangerous stimulus. Additionally, the exposure of the left side of the body toward conspecifics might better facilitate using the hand that is more involved in social interactions, as previously found in gorillas and chimpanzees.…”

The evolution of brain lateralization: a game-theoretical analysis of population structure

“…First, prey lateralized in the same direction have a greater chance of keeping together as a group. This assumption is motivated by empirical research showing that lateralization can affect both when predators are detected (Lippolis et al 2002) and the direction in which prey tend to escape (Cantalupo et al 1995). Our second assumption is that predators are better at capturing the prey type they meet more often.…”

“…For instance, toads (Lippolis et al 2002), chickens (Evans et al 1993) and fishes (De Santi et al 2001) react faster to predators approaching from the left. Left-side biases also exist in interactions with conspecifics in fishes (Sovrano et al 1999, toads , lizards (Deckel 1995), chickens (Vallortigara 1992;Vallortigara et al 2001), sheep (Peirce et al 2000) and primates (Casperd & Dunbar 1996;Vermeire et al 1998;Weiss et al 2002).…”