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The fact that white sharks not only stay close to each other but also have preferred buddies got me wondering if maybe these animals were more social than people thought. Researchers found that white sharks would often turn up at cage diving sites with the same individuals time and time again. While the sharks may not be cooperating, they can still potentially benefit by hanging out with each other.įurther studies on white shark behavior in Australia took this a step further. The biologists suggested that if one shark killed a marine mammal, other, nearby sharks would register this information and quickly approach the site of the kill, perhaps hoping to eat from the remains of the prey. In 2001, researchers in California published a paper describing how white sharks patrolling a seal colony at Año Nuevo Island would remain within “eavesdropping” distance of each other. Sharks generally hunt by patrolling the waters adjacent to seal colonies and ambush seals at the surface. White sharks travel to seal colonies during the seal’s breeding seasons in the summer and fall. Yannis Papastamatiou, CC BY-ND Hints of a social shark Journal compilation © 2010 British Ecological Society.Great white sharks were historically seen as individualistic hunters, but previous research hinted at social behaviors. Individual specialization may be an important feature of trophic dynamics of highly mobile marine top predators and should be explicitly considered in studies of marine food webs and the ecological role of top predators.

The differences in individual dietary specialization between tiger sharks and bull sharks results in different functional roles in coupling or compartmentalizing distinct food webs. Relative resource abundance and spatial variation in food-predation risk tradeoffs may explain the differences in patterns of specialization between shark species. In contrast, isotope values of individual bull sharks were stable through time and their wide population level niche breadth was explained by variation among specialist individuals.

The population niche breadth was explained mostly by variation within individuals suggesting tiger sharks are true generalists. Despite wide population-level isotopic niche breadths in both species, isotopic values of individual tiger sharks varied across tissues with different turnover rates.

Stable isotope values from body tissues with different turnover rates were used to quantify patterns of individual specialization in two species of 'generalist' sharks (bull sharks, Carcharhinus leucas, and tiger sharks, Galeocerdo cuvier). Because of their position at or near the top of many marine food webs, and the possibility that they can affect populations of their prey and induce trophic cascades, it is important to understand patterns of dietary specialization in shark populations. But there is increasing evidence that individual level dietary specialization may be common in many species, and this has not been investigated for many marine apex predators. Apex predators are often assumed to be dietary generalists and, by feeding on prey from multiple basal nutrient sources, serve to couple discrete food webs.