Hawaiian Bottlenose Dolphin: At the Dolphin Research Center in Grassy Key, Florida, there stands a dolphin-statue monument marking the grave of a fourteen-year-old female bottlenose dolphin named Mitzi who died in 1972 of a heart attack. She is remembered as the original “Flipper,” star of a television series that first aired in the mid-sixties and later prompted a film starring Chuck Connors, Luke Halpin and a new set of aquatic performers. Flipper spawned a huge fan club of “dolphin-lovers,” many of whom had little experience with bottlenose dolphins and may never have visited Hawaii, where na’ia has long been a cherished resident. One of fifteen species of wild dolphins believed to either live in or migrate through Hawaiian waters, Hawaii’s bottlenoses often are observed as a single animal bow-riding a boat or keeping company with a whale. Capable of speeds topping 25 miles an hour, they seem to prefer shallow inshore waters or the deep channels between the main islands. Sometimes they appear in small herds of 2-12 animals. Their distinctive “smiling” mouths and stubby snouts or rostrums make them easy to- identify. Large in size, bottlenoses average 7-12 feet in length and weigh 600-850 pounds. Coastal-preferring individuals are gray or light gray in color, while deepwater residents are almost black. Both have whitish underbellies. Distinctive scars, nicks, and scratches help scientists to keep track of the local population. Classified as a “toothed whale” of the suborder of odontocetes, bottlenoses are cetaceans, as are all whales and dolphins. Not a fish, the bottlenose is a warm-blooded, air-breathing mammal that gives birth and nurses its young. Females mature between 5-13 years of age, males at 8-13 years. Mating and calving take place year round, with most births occurring spring or fall, following a gestation period of 12 months. Born tail-first and eyes open, baby shadows Mom as she leads it toward the surface for its first breath. Calves may nurse past 20 months of age but by six months will play with and consume small fish. Full-grown bottlenoses enjoy a varied diet of fish, squid, octopus, small rays and sharks, along with an occasional feast of shrimp and other bottom dwellers. They use echolocation — that extraordinary ability to bounce sounds off objects to determine size, shape and distance — to locate prey hiding in sand. In Shark Bay, Australia, bottlenoses have been observed carrying sponges on their rostrums, apparently as a means of protection as they nose along the bottom, searching for a buried meal. Bottlenoses form same-gender, possibly life-long associations with other bottlenoses. Feeding singly or in groups, they will sometimes hunt cooperatively by encircling a school of fish and then darting in one at a time to grab a snack. They have been known to work together with humans to herd fish toward fishing nets. In Laguna, Brazil where “cooperative fishing” has endured for more than a century, dolphin participants expect to be rewarded with “stragglers.” Another bottlenose behavior involves the “whacking” of prey fish with flukes to stun them and make them easier to catch. Among the most intelligent creatures on the planet, bottlenoses have brain to body ratios only slightly smaller than humans. They lack a sense of smell, but hearing is acute, allowing the reception of high frequency sounds ten times or more in excess of what the human ear can handle. Each dolphin has its own identifying “signature whistle,” plus a sophisticated vocabulary of clicks and other whistles. Scientists still are working to de- code dolphin communication. Studies suggest that this species also may possess a magnetic sense that aids in navigation. Stories of bottlenoses “rescuing” humans first surfaced in ancient times and new ones occasionally appear. Bottlenoses clearly can master complicated behaviors, perform on cue and seem to relish doing so. Stars such as Flipper give every indication of enjoying their work, but dolphins in captivity typically do not live as long as dolphins in the wild. Wild females can live over 50 years — males about 40 years. Threats to their longevity include boat traffic, entanglement in fishing gear, nets and other marine debris, general habitat degradation, chemical and noise pollution, and destructive fishing methods. Dolphin-safe tuna labels inform consumers that fishing methods used to catch the tuna in question are not as damaging to dolphins as they once were. But in some parts of the world, bottlenoses still are hunted for food, oil, and leather and because they compete for food fishes. Large sharks, such as tigers and great whites, are their natural predators. We can help protect our Hawaiian bottlenose population by properly disposing of all trash and plastics, reducing coastal water pollution, and taking care not to disrupt critical feeding, resting and social behaviors. Approach no dolphin closer than fifty yards and limit viewing time to no more than half an hour. Flipper would “applaud” these time-tested conservation efforts.
Pages to are hidden for
"Hawaiian Bottlenose Dolphin At the Dolphin Research Center in Grassy"Please download to view full document