Dolphins are marine predators primarily recognized for their diets that include a significant amount of fish. Their predatory success stems from specialized physical attributes and highly coordinated hunting techniques. They are adaptable carnivores, able to locate and capture prey in diverse marine environments.
What Dolphins Consume
Dolphins consume a varied diet, with fish forming a substantial part of their intake. Common fish species include mackerel, herring, and cod, though specific types vary by dolphin species and geographical location. For instance, bottlenose dolphins in Scotland may favor salmon, shifting to herring and mackerel when salmon are less available. Coastal dolphins often feed on fish like mullet and catfish, while offshore dolphins consume deep-sea fish and squid.
Dolphins also regularly consume cephalopods like squid and octopus, especially in deeper ocean waters. Some species, like Risso’s dolphins, predominantly eat cephalopods. Crustaceans, including shrimp and crab, are also part of their diet, particularly for river dolphins and those in coastal or freshwater habitats. As opportunistic feeders, dolphins eat what is readily available, even occasionally consuming jellyfish or other marine invertebrates.
Hunting Strategies
Dolphins employ sophisticated methods to locate and capture prey, often demonstrating intelligence and social coordination. Echolocation is a primary tool, allowing them to “see” with sound in murky waters or at night. Dolphins emit high-frequency clicks from their nasal passages, focused through a fatty organ called the melon. These sound waves bounce off objects, and returning echoes are received by the dolphin’s lower jaw, providing detailed information about prey location, size, and movement.
Cooperative hunting is a common and effective strategy among dolphin pods. One technique involves herding schools of fish into a dense “bait ball,” with dolphins taking turns charging through to feed. Another method is tail-slapping, where dolphins forcefully slap their flukes on the water to stun or disorient fish. Some species, like bottlenose dolphins, engage in “strand feeding,” working together to drive fish onto a beach or mud bank before sliding back into the water.
Dietary Needs and Adaptations
Dolphins have high dietary needs due to their active lifestyle and metabolism. An adult dolphin typically consumes 4% to 6% of its body weight in food daily, translating to 15 to 30 pounds depending on species and size. A nursing mother’s daily intake is considerably higher, often around 8% of her body weight. The exact quantity also depends on the prey’s caloric value; more squid might be needed than fattier fish like mackerel to achieve the same energy.
Their bodies are adapted for a diet of whole fish, as dolphins do not chew their food. They typically swallow fish whole, often headfirst to prevent spines from catching in their throats. For larger prey, they may shake or rub it on the ocean floor to break it into manageable pieces. A dolphin’s stomach is compartmentalized for rapid digestion, supporting their constant energy demands. Factors like age, activity level, and reproductive status influence their specific caloric requirements.