During movement, however, periods of stabilization are interspersed with non-compensatory saccades that abruptly shift gaze position. We found that the majority of eye movements are compensatory for head movements, thereby serving to stabilize the visual scene. To determine how mice target their gaze during natural behavior, we measured head and bilateral eye movements in mice performing prey capture, an ethological behavior that engages vision. Proceedings of the Royal Society of London, Series B, 272, 1203 – 1207.Many studies of visual processing are conducted in constrained conditions such as head- and gaze-fixation, and therefore less is known about how animals actively acquire visual information in natural contexts. ![]() (2005) Prey survival by predator intimidation: an experimental study of peacock butterfly defense against blue tits. (1984) Proceedings of the California Academy of Sciences ser43:221-238 The biology of Carcharodon carcharias : 229 – 240. (1996) Shape Discrimination and Visual Predatory Tactics in White Sharks. (1990) Behavioural decisions made under the risk of predation: a review asn prospectus. (1957) The function of eyespot patterns in the lepidoptera. Additionally, the concept that “eyespots” used in mimicry (or finspots in fish) can reduce the risk of a predatory attack is well supported (Blest 1957, Vallin et al., 2005) and further complements the theory to “Shark Eyes”.īlest, A.D. (Above) Hypothesized decision tree of predatory tactics by white sharks on surface borne Cape fur seals at Seal Island, South Africa. It’s at this “Gather Info” stage that “Shark Eyes” aims to influence the sharks risk assessment, altering the shark’s behavior to “Abort”.įigure 1. Once a shark sees the “Shark eyes” and realizes it has been detected, it may now be optimal for the shark to abandon its attack.Īs described by Martin et al., (2005) the stages of predatory behavior by a white shark involves a “Gather Info” stage before deciding to “Strike” or “Abort” an attack. Similarly, Strong (1996) observed in numerous occasions that fur seals and sea lions easily avoided white sharks, suggesting that once the shark was visually detected, the chance of capture of the seal prey drop considerably. For example, an adult white shark is usually not agile enough to capture a fleeing, darting seal hence it generally attacks its prey by surprise (Tricas and McCosker, 1984). By taking away the element of surprise, the shark has a reduced chance of successfully capturing its prey. “Shark eyes” therefore aims to alter the sharks risk assessment and deter the shark from attacking. “Shark Eyes” is intended to signal the approaching predator that it has been detected, effectively saying “I’ve seen you” and thereby altering the shark’s predatory behavior. When predating, sharks undertake a risk assessment before attacking its prey (Lima and Dill, 1989 Martin et al., 2005) and it’s at this point where “Shark eyes” is designed to assist watermen. A shark’s vision is well developed and more elaborate than most fishes (Gilbert, 1963), having duplex retinas containing both rod and cone photoreceptors (Gruber & Cohen, 1985) indicating they have excellent visual capabilities and ability to see color. ![]() Strong(1996) found sharks were initially attracted to their prey with sense of smell but appeared to use vision the closer it approached. Sharks are visual predators that predominately use the element of surprise when attacking (Strong,1996), usually attacking from behind and beneath its prey (Tricas and McCosker 1984). Shark Eyes – the design of the eye – achieves depth of field through contrast. ![]() Science is unsure as to whether or not sharks can see color although many scientists believe they can and they do know they can see contrast. Hours of research has gone into designing a set of eyes that we know sharks can see. Shark Eyes is unlike any of the shark's natural prey and is designed to mimic that of a human eye. ![]() “Shark Eyes” aims to alter the sharks initial risk assessment thereby altering its “strike” behavior to an “abort” behavior (Martin et al., 2005). Sharks employ predatory tactics which involve a risk assessment before attacking it’s prey (Lima & Dill, 1989). Sharks are ambush predators, relying heavily on the element of surprise to capture prey (Strong, 1996). Sharks have been found to detect surface prey visually (Strong, 1996) having high visual capabilities (Gruber & Cohen, 1985). Recent research indicates that this includes their vision – they do in fact have superb visual capabilities. It is well known that sharks have superior senses. Sharks have excellent visual capabilities
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