Animal movements are never random; they are driven by a myriad of factors, both internal and external. But understanding an animal’s movement in its natural habitat is like deciphering a complex puzzle: pieces may be missing, misplaced in a box, or the instructions may be written in a foreign language not on Google Translate’s list.
Why do monarch butterflies travel thousands of miles during their migration, only to return to the same wintering grounds each year?
How do salmon return to the rivers where they were born after a long ocean migration that spans thousands of miles?
How do African elephants know the location of distant water sources as they roam the vast savanna?
The questions are endless.
Predator behavior is known to be influenced by a myriad of factors, including energy requirements, reproductive status, environmental conditions, prey availability, competition, and predation risk.Carcharodon carcharias), these factors play a key role in shaping shark movements in the vast marine environment, especially the movements of aggregations around pinniped colonies. These aggregations act as feeding hotspots, especially for larger individuals that are able to catch such prey. Not all sharks are equally skilled at cooking, and young individuals hone their skills on small prey before progressing to a diet of seals as adults. But it is not known why individuals choose specific aggregation sites or how their movements differ depending on size, sex and environmental conditions. The answer is… well, it will become clear in the future. And Groundbreaking Research A research team led by Dr Oliver Jewell of Murdoch University in Western Australia recently investigated how the movements of great white sharks off the coast of central California are influenced by internal and external factors and discovered one of the missing pieces of the puzzle. “After tagging 22 sharks over three years of PhD fieldwork, we discovered that shark movements are shaped by the habitat they swim in, meaning sharks behave differently in different places, regardless of their size or sex,” Dr Jewell said in a Facebook post.
The sharks displayed unique movement characteristics that were primarily shaped by habitat and population attributes. Juvenile sharks from Aptos followed erratic trajectories, while juvenile sharks from Ano Nuevo and the Farallon Islands dived deeper and chose more purposeful routes. Nighttime movements differed significantly from daytime activity, with nocturnal sharks exhibiting lower activity levels and straighter swimming trajectories.
Understanding the nuances in predator movements has profound implications for conservation and management efforts. “These results are important because they suggest that the same sharks likely behave differently in different places,” said Jewell. Uncovering the drivers of movement patterns will enable researchers to better predict and mitigate human-wildlife conflicts, protect critical habitats, and inform the design of marine protected areas. As our understanding of great white shark movements improves, so will our ability to protect these predators and the delicate marine ecosystems they inhabit.