Bottlenose Dolphin Order Cetacea Sub-Order Odontoceti Family Delphinidae Genus & Species Tursiops truncatus Length 11 to 13 feet Weight 330 to 440 pounds Sexual maturity About 8 years Mating Mating can occur at any time, but most births take place during the summer Number of Young Single calf Call Extensive vocabulary of whistles and clicks Habit Sociable Diet A wide range of inshore fish, particularly capelin, anchovy, salmon, and shrimp Lifespan Up to 50 years Bottlenose dolphins usually mate in the spring and summer. The females give birth underwater to a single calf 10 to 12 months later. Several dolphins surround the mother to assist with her delivery and to protect her and the baby from shark attacks. Sharks are attracted to the scene by the blood which is released during birth. Sometimes the dolphin helpers will tug gently at the baby's tail as it emerges whistling encouragement to mother and youngster. They swim together as a group to guide the newborn dolphin to the surface for its first breath of air. The mother nurses her calf for at least 16 months, so she usually breeds only once every two to three years. Each time, she is likely to breed with a different mate. Dolphins are very sociable animals that generally live in groups. Their friendly, cooperative behavior is vital to their survival. When a dolphin is sick or injured, its cries of distress summon immediate aid from other dolphins, who try to support it to the surface so that it can breathe. Dolphins spend a large part of the day playing. They use whistles and clicks to contact each other. Dolphins eat a wide variety of fish, and their hunting behavior varies according to the availability of food. When large schools of fish are present, as many as several hundred dolphins will cooperate in catching the fish by communicating with one another. They drive the fish into a dense mass and force them to the surface of the water, making it impossible for the fish to escape. They also emit loud sounds to further confuse the prey. Dolphins usually hunt during the day. However, when fish begin migrating or are scarce, dolphins become nocturnal hunters. They search for squid and bottom-dwelling fish which are active at night. Man and dolphins conflict when they compete for fish; each year, thousands of dolphins drown in nets. Sometimes schools of dolphins get stranded on shore. conservationists try to return them to deep water but are rarely successful. Scientists believe that schools become stranded when a single dolphin's echo-location system is upset. Its distress calls cause others to follow it to their deaths. DID YOU KNOW? Dolphins can eat at depths of 6 feet and can stay submerged for up to 15 minutes Sharks and killer whales prey on dolphins To breathe when they are asleep, females lie on the water's surface with their blowholes exposed to the air; males sleep just below the surface and rise to breathe periodically as a reflex action Information is Copyright IMP BV/IMP Inc.  Wildlife Fact File