Recent Study Highlights & Examples

White sharks appear to hunt solitary juvenile Cape fur seals near their primary entry and exit point early in the morning, when light levels are low. Stalking is conducted from near the bottom, from sufficient depth to remain undetected during approach, and the attack launched vertically. This strategy maximizes a shark’s chance of catching a seal unaware, resulting in a fatal or incapacitating initial strike. Stealth and ambush are key elements in the white shark’s predatory strategy. Further, recognizable individual white sharks display distinct predatory strategies and some enjoy a predatory success rate of roughly 80%. Moreover, spatial patterns of shark predation at Seal Island are nonrandom. Sharks station themselves at specific points which represent an optimal balance among prey detection, capture rates, and competition. Smaller sharks exhibit more dispersed prey search patterns and have lower predatory success rates than larger conspecifics, suggesting possible learning with experience.

FIGURE (right): (A) Peak 1% geoprofile of 340 white shark attacks on Cape fur seals at Seal Island, South Africa, over primary seal travel path from and returning to the island (a triangle originating at LP and widening to the south; see Figure 1B); the geoprofile shows a strong, well-defined anchor point. (The ranges for the z-score — the likelihood value of the anchor point for a given pixel in a geoprofile — are depicted with different colours, outlined in the legend). Peak 1% geoprofiles of white shark attacks at Seal Island by total length, showing increasing focus of anchor point with increasing size (i.e., experience): (B) small sharks (<3 m); (C) medium sharks (3-3.5 m); and (D) large sharks (>3.5 m).Figure from Martin et al. 2009. Journal of Zoology, 279: 111-118

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