Bottlenose dolphins are amazing creatures. They are believed to be among the most intelligent animals on Earth. Dolphins are also social animals well known for their playful and carefree nature. They are so beautiful. Bottlenose dolphins are very interesting. In the next few paragraphs you will be reading about the wonderful animals they are.

 

Bottlenose dolphins are extremely large mammals. These dolphins have mainstreamed bodies with a circular head containing a distinctive beak. The beak is usually short and stubby which is how they eventually received the name "bottlenose" dolphins. They have slightly pointed flippers and a sickle-shaped fin. They weigh 440 to 600 pounds and reach up to an average of 10 feet (some 14).

 

Dolphins can swim up to 40 km/hr. They have a special skin for swimming that reduces turbulence. They swim really fast for such a big animal. Dolphins need to be fast in case of danger though. They also have sharp eyesight. Their eyes are located at the sides of the head and have a tapetum lucidum (a layer of specialized reflecting cells in the choroid behind the retina of the eye) which aids their eyesight in dim light. These are the physical characteristics of a Bottlenose dolphin. Bottlenose dolphins live in groups of pods, containing up to 12 animals. These are long-term social units.

 

Typically, a group of females and their young live together in a pod and juveniles in a mixed pod. Several of these pods can join together to form larger groups of one hundred dolphins or more. Males live mostly alone or in groups of 2-3 and join the pods for short periods of time. They usually are found in both the Pacific and Atlantic Oceans. Bottlenose dolphins prefer warm to tropical water. Their diets consist mainly of small fish, occasionally cephalopods (squid and octopus) and other sea life.

 

Their peg-like teeth serve to grasp but not to chew food. When a school of fish has been found the animals work as a team to keep the fish close together and maximize the harvest. They also search for fish alone, often bottom-dwelling species. Sometimes they will employ "fish whacking" whereby a fish is stunned (and sometimes thrown out of the water) with the fluke to make catching and eating the fish easier. They consume 13 to 33 pounds of food each day. Dolphins are also carnivores. They eat different food according to where they live and their ecosystem.

 

Dolphins do have predators, for example, large shark species such as tiger sharks, dusky sharks and bull sharks. Orcas may also prey on them but this seems very rare. Bottlenose dolphins often live 30 to 50 years but with these natural predators some will not live that long. Dolphins are also predators themselves. They show aggressive behaviors.

 

This includes fights among males for rank and access to females as well as aggression towards sharks and other small species of dolphins. The Dolphins search for food is aided by a form of echolocation similar to sonar: they locate objects by producing sounds and listening for the echo. Could you imagine making sounds to find food? Bottlenose dolphins can also communicate with body movements which is something I find very interesting.

 

Their population worldwide is not known. In the eastern tropical Pacific the population is estimated to be 243,500 while in the waters of Japan the population estimates as low as 37,000. Add those up and you get 280,500, that is a lot of dolphins. Bottlenose dolphins' sexual maturity for males is 7-12 years of age and for females it is 5-10 years.

 

Their gestation period is approximately 12 months. The calf size can get up to 35-50 inches long and weight 30-90 pounds. Females dolphins normally have one calf per pregnancy. While twin fetuses have been reported this is thought to be very rare and none are known to survive. Their calving interval is approximately every 2 to 4 years.

 

The female nursing process is very interesting. Female dolphins posses two mammal glands which produce a rich milk to nourish her young. Young calves may begin eating fish within a few months after birth but may continue to nurse for 1 to 2 years or more. Females also produce one offspring every 2 to 3 years after a gestation period of 12 months.

 

Young stay with their mothers for 1 year. Sometimes the mother will get help from another female in caring for offspring. From 1959 to 1991 an estimated 7,000,000 dolphins were killed by tuna fisherman. In 1995 the total number killed by American fisherman was 114. Unnecessary dolphin deaths still happen everyday in countries where enforcement of dolphin-safe laws is less stringent.

 

In the late 1980's a worldwide movement to prevent the deaths of dolphins by tuna fisherman began. Laws were passed and fishing techniques changed. Because of these laws the total number of dolphins killed in nets decreased.

 

In conclusion I have learned a lot about Bottlenose dolphins. I have learned about their predators, their diets, how they swim and much more. They are very intelligent marine animals. They are a carefree creature and very playful. I really enjoyed researching their way of life. Dolphins are amazing animals and I hope to learn even more about them.

 

Author: Breanna Y.

Date Published: April 2006

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Images swfsc.nmfs.noaa.gov/.../ case/bottlenose.html http://www.nist.gov/public_affairs/colloquia/20030328.htm http://www.nmfs.noaa.gov/pr/permits/faq_mmpermits.htm

 

The reserch was found... http://www.dolphintrainer.com/dolphins_profile.htm http://www.kidsplanet.org/factsheets/dolphin.html http://www.npca.org/marine_wildlife/dolphin.asp http://www.seorf.ohiou.edu/~agl51/facts.htm