Key Highlights
- Orcas have been spotted hunting juvenile great white sharks in the Gulf of California for the first time.
- The orcas use a technique to flip the sharks upside down, extract their livers and share among themselves.
- Scientists suspect climate change may be altering shark nursery areas, exposing them to orca predation.
- This behavior could indicate changing diets of killer whales as they adapt to environmental changes.
New Insights into Orca Hunting Behavior
Orcas, known for their advanced intelligence and strategic hunting techniques, have been observed engaging in a novel hunting method that targets juvenile great white sharks in the Gulf of California. This behavior has been documented by researchers who have named this specific orca pod “Moctezuma’s pod,” highlighting the significance of their findings.
The Hunting Technique
According to marine biologist Erick Higuera Rivas, an author of a study published in the journal Frontiers in Marine Science, these orcas use a method that involves flipping juvenile sharks upside down. This technique is believed to induce a state called tonic immobility, which paralyses the shark temporarily and renders it defenseless.
“The orcas push the shark to the surface, work together to turn it upside down, and then take the shark underwater where they can extract its energy-rich liver,” explains Rivas. “This behavior is a testament to orcas’ advanced intelligence, strategic thinking, and sophisticated social learning.” The pod was observed carrying out two hunts during which they killed three juvenile white sharks.
Environmental Factors
The researchers suggest that climate events like El Niño may have altered the nursery areas of great white sharks in the Gulf of California. This exposure to orca predation could be a new seasonal target for each generation of juveniles, as they are less experienced and easier to catch.
Salvador Jorgensen, another study author from California State University, notes that “adult white sharks react quickly to hunting orcas and completely evacuate their seasonal gathering areas. However, juvenile white sharks may be naive to orca predation.” He adds, “We just don’t know yet whether white shark anti-predator flight responses are instinctual or need to be learned.”
Implications for Great White Sharks
The latest findings indicate that great white sharks might face increased pressure from orcas due to environmental changes. This could have significant implications for the species’ population dynamics and behavior in the Gulf of California.
“Future studies should continue to monitor the shifting ranges and aggregation sites of juvenile white sharks driven by ocean warming,” suggests the study. The research underscores the importance of ongoing monitoring and further investigation into how climate change affects marine ecosystems, particularly predator-prey relationships.
