Bottlenose Dolphins

BOTTLENOSE DOLPHINS
This dolphin found throughout the world and also in Australia, scientific name is Tursiops truncatus
Its name comes from its short rounded snout or "beak" which resembles a bottle

DESCRIPTION
The bottlenose dolphin can look very different depending upon where it is seen around the world.
Also inshore dolphins can appear different to the larger "offshore" bottlenose dolphins
The size of the average bottlenose dolphin is 2.5 to 3 meters Males are a little longer than females.
Their average weight is around 200 kg but large males can grow up to 650 kg
These sleek streamlined dolphins general colour is dark - medium grey on their backs fading to a light grey, white on the belly and on their bottom jaw
So when looking from above the dark colours blend in with the sea floor or dark deeper water, and when viewed from below the lighter colour blends in with the sky or lighter coloured surface water.
Bottlenose dolphins look like they are smiling, and there is a "sharp" crease between their snout and the top of their head, as well as other lines around the face region (see picture)
They have a single blow hole at the top of their head.

DISTRIBUTION & LOCATION
They are found all over the world and all around Australia in cold temperate to tropical waters
Around Australia they are found in bays and waterways, surf coasts, lagoons and also in the open sea

HABITS SOCIETY ETC
Bottlenose dolphins are very sociably creatures living in a group known as a pod.
The number of dolphins to a pod varies significantly.
Inshore populations in southern Australian waters generally range from 5 to 20 with offshore groups being much larger, up to 60
Within the pod there is a strong sense of unity or bonding, with lots of interaction (touching, chasing, noises etc) between members happening constantly.

SENSES
Bottlenose dolphins have the sense of Sight (both in and out of the water),
Hearing (Very good),
Taste (they have taste buds)
and Touch (they can sense water moving over its body as well as touch and rub each other with fins etc they have a limited sense of smell.

ECHOLOCATION
By creating clicking sounds (pulses of ultrasonic sound) and waiting for it to "bounce back" off objects, dolphins can create a "picture" of their surrounds (depending on how long it takes for the click echo to return)
This echo-location is primarily used for the locating and hunting of prey.

SWIMMING & DIVING & JUMPING

Dolphins swim by moving their flukes (tail fins) up and down
They can swim up to 37 km/hour but generally "cruise" at around 10 km/hour
Generally their dives last up to 3-4 minutes or less, especially in coastal waters, but dives in the ocean have been recorded at up to 15 minutes

FEEDING
Coastal dolphins eat a variety of fish species, squid, shrimp, octopus, krill etc depending upon what is available at that location.
The average adult eats around 15kg a day and they do not chew their food, they swallow the fish whole
Co-operating together they sometimes trap schools of fish between the shore and their own bodies, or encircling or "rounding up" schools of fish to then dive into the tightly packed fish to eat.

BREEDING
Dolphins can live over 30 years (up to 50 years has been recorded)
They start to breed around the age of 10
Bottlenose dolphins can breed at any time of the year.
A female is pregnant for a year, the calf is then born in the water, the young then suckles for about 1 1/2 years and the young stays with the mother for a further 4 years
At birth the calf can be anything from 0.7 meter to 1.3 in length and up to 30 kg

THREATS
Accidental capture in fishing nets, (trawling, drift and gill nets)
Destruction and/or degradation (Pollution and rubbish) of habitat
Over fishing is reducing feed for the dolphins Over zealous tourist activities
Diseases and parasites
Predators such as killer whales and sharks such as tiger and dusky sharks
Human hunting for their oils, skins etc