The bottlenose dolphin is one of the most well-known species of marine mammals.Bottlenose dolphins are light to dark gray over their dorsal surface, fading into a white or cream along their ventral region. They have a streamlined fusiform body shape. The source of their common name, bottlenose dolphins exhibit a pronounced anterior rostrum (often referred to as a beak), typically three inches in length. The rostrum generally contains 76-98 conically shaped, homogenous teeth – with tooth counts varying among individuals. Their dorsal fin is falcate.
There are two distinctive ecotypes of bottlenose dolphins. The coastal ecotype, which are the dolphins found in our local waters, typically exhibits smaller average body size with relatively larger flipper size. Comparatively, the offshore ecotype typically exhibit larger average body size and darker coloration – among other morphological distinctions.
These particular dolphins range in lengths from 6 to 12.5 feet with males being slightly larger than females. Adult dolphins weigh between 300 to 1,400 pounds. This is a long-lived dolphin species with a lifespan of 40-45 years for males and more than 50 years for females.
Bottlenose dolphins are commonly found in groups of 2 to 15. They are generalists and feed on a variety of prey items endemic to their habitat, foraging individually and cooperatively. Like other dolphins, bottlenose dolphins use echolocation to locate and capture prey. Coastal bottlenose dolphins, like the ones in our waters, prey on benthic invertebrates and fish. Bottlenose dolphins employ multiple feeding strategies, including “fish-whacking,” where they strike a fish with their flukes and knock it out of the water.
Sexual maturity varies by population and ranges from 5-13 years for females and 9-14 for males. Calves are born after a 12-month gestation period and are weaned at 18 to 20 months. On average, calving occurs every 3 to 6 years. Females as old as 45 years have given birth.
Bottlenose dolphins are found in temperate and tropical waters around the world. There are coastal populations that migrate into bays, estuaries, and river mouths as well as offshore populations that inhabit pelagic waters along the continental shelf.
Bottlenose dolphins are top ocean predators with few predators of their own. Sharks and killer whales occasionally prey upon dolphins. Humans represent a major threat to bottlenose dolphins who are accidentally caught in fishing gear or entangled in discarded gear and monofilament line. Dolphins are still hunted in some parts of the world.
Did You Know?
- Dolphins frequently ride the bow wake of the stern wake of boats. They have been seen jumping as high as 16 feet out of the water and landing on their backs or sides, in a behavior called a breach.
- Both young and old dolphins chase one another, carry objects around, toss seaweed to one another, and use objects to invite each other to interact. Such activity may be practice for catching food.
- Bottlenose dolphins often cooperate when hunting and catching fish. In open waters, a dolphin pod sometimes encircles a large school of fish and herds them into a tight ball for easy feeding. Then the dolphins take turns charging through the school to feed. Occasionally dolphins will herd fish to shallow water they are easy prey.
- Bottlenose dolphins generally do not need to dive very deeply to catch food. Depending on habitat, most bottlenose dolphins regularly dive to depths of 10-150 feet. They are, however, capable of diving to some depth.
- Bottlenose dolphins live in fluid social groups called pods. The size of a pod roughly varies from 2-15 individuals. Several pods may join temporarily to form larger groups called herds or aggregations. Up to several hundred animals have been observed traveling in a single herd.
- The dolphin’s sleek, fusiform body, together with its flippers, flukes, and dorsal fin, adapt this animal for ocean life. A dolphin’s forelimbs are pectoral flippers. As it swims, a dolphin uses its pectoral flippers to steer and, with the help of the flukes, to stop.
- Bottlenose dolphins routinely swim at speeds of about 3 to 7 miles per hour.
- On average, a dive may last 8 to 10 minutes.
- Group composition and structure often are based on age and sex. Adult males tend to group together in pairs or in threes. Females with calves associate with one another. Individuals may leave one group and join another.
- Adults eat about 4-5% of their body weight per day. Bottlenose dolphins often cooperate when hunting and catching fish. They use tools such as sponges to protect their rostrum (beak) while foraging on the bottom of the ocean.
- National Oceanic and Atmospheric Administration (NOAA Fisheries)
- Seaworld Parks and Entertainment
- National Aquarium
- National Geographic
Local Pod Information and Identification Coming Soon!