Whales
Overview
Five main features define a mammal - all have hair, are air breathers, warm blooded, give birth to live young and have the ability to suckle their young. There are four main orders of mammals that are adapted to life in the sea; Order Cetacea (whales, dolphins and porpoises), Order Pinnipedia (seals and walrus), Order Sirenia (manatees and dugongs) and Order Carnivora (sea otter and polar bears).
Whales are a unique group of mammals. Their acute senses, streamlined bodies and thick layer of insulating blubber enables them to survive in diverse marine environments. Whales are divided into two families including Baleen whales and Toothed whales.
Baleen whales have an upper jaw, which is long, broad, and flat. Instead of teeth, they have baleen plates made of tough, bristle-like fibres which 'hang' along the edge of the jaw like a broom. The bristles act as a filter to strain phytoplankton (tiny plants) and zooplankton (tiny animals) from the sea.
Toothed whales, including dolphins, use their teeth to grasp prey such as fish, squid, octopus and other whales. They use their tongue to turn the fish around so they are swallowed head first and whole.
The oceanic dolphins and porpoises, both Toothed whales, are of the same order - Cetaceans. Some controversy exists on whether dolphins and porpoises are of the same family. The most obvious differences are that dolphins have a long rostrum, curved dorsal fin and conical-shaped teeth. Porpoises have a rounded 'nose', triangular dorsal fin and spade-shaped teeth. The dolphin has a larger brain than the porpoise in relation to body size.
Why did you build Dolphin Cove?
In 1996 Sea World opened Dolphin Cove. This area consists of 4 sandy bottomed salt water pools, three with a depth of 7 metres and one isolation pool with a depth of 2 metres. The objectives behind creating Dolphin Cove were to provide an environment very similar to a dolphin's natural habitat and to enable us to have the facilities to continue our successful breeding program.
What types of Dolphins do you have at Sea World?
At Sea World we have one Indo? Pacific Humpback Dolphin and approximately 30 Bottlenose Dolphins, which can be divided into two sub groups, the Onshore Bottlenose and the Offshore Bottlenose.
Do you keep your male and female dolphins together?
Dolphins are divided into two groups and these groups naturally occur in the wild. Firstly there is a matriarchal pod full of females and young calves. Male calves are sent with the male dolphins once they reach sexual maturity. Secondly there is a bachelor pod, consisting of all males. Here at Sea World we have two bachelor pods and two matriarchal pods.
Does Sea World catch dolphins from the wild?
No, when Sea World was founded in 1971, dolphins were captured from the wild. This has not happened since 1996 and the majority of our dolphins here at Sea World are a result of our breeding program.
How does Sea World manage the dolphin breeding program?
All the dolphins at Sea World are DNA tested to determine blood lines and to ensure that these blood lines are not cross bred. Dolphins reach sexual maturity around the age of 6, with males not reaching sexual maturity until about 8. Females at the age of 12 have a higher percentage of surviving calves, therefore we have no females younger than 12 in our breeding program. Males have their testosterone levels checked to ascertain their sexual peak and then they are placed with an appropriate female. Once the female is pregnant the male dolphin is removed from that pool. Breeding females have their blood tested every two weeks. Pregnant females then have an ultrasound after 6 months to monitor her calf. When calves are born they weigh approximately 15kgs and are 1 metre long. They will stay with their mother and suckle milk until they are between 2 and 3 years of age. Currently at Sea World we have 3 calves of varying ages and in the future we will look at artificial insemination as a way of increasing our gene pool.
How much does it cost per year to keep a dolphin at Sea World?
It is very difficult to calculate yearly costs for maintaining and caring for our dolphins as there are many contributing factors. Each dolphin eats approximately 15-20 kilograms of food per day. We have specialised veterinarian, husbandry, training staff and our Life Support Systems personnel to monitor the water purity and the cost of operating and maintaining various dolphin areas.
Are collisions between whales and boats common and are there any boat design features that could reduce the occurrence?
As the numbers of whales migrating into Queensland each winter continue to grow and boating traffic on our waterways intensifies, the numbers of collisions between boats and whales are increasing. With the increase in population and tourism, the use of our oceans for leisure activities is also increasing. Activities such as whale watching are often pushing limits to get as close to these incredible mammals as possible. The growth in water traffic threatens whales in many ways including the risk of collisions with boats, pollution and habitat interference.
All whales, dolphins and porpoises are 'hyper sensitive' to loud persistent sounds underwater. Some of these sounds have a range over 100km and can cause stress, disorientation or physical harm. Injuries are not only sustained from the impact of the hull of a boat, but also the propeller.
To eliminate the occurrence of boat collisions with whales there is a need for more information on whale migration patterns in order to educate the public about possible areas with large whale numbers at certain times of the year. Tourist operators such as whale watching businesses need to adhere to strict guidelines on acceptable viewing distances.
Regarding boat design, there have been plans to design propeller guards and also a type of identification system attached to boat hulls to identify large objects within the boats intended path.
How many generations of dolphins do you have at Sea World?
Sea World currently has three generations of Bottlenose dolphins; Splash (grandmother), Squeak (mother) and Nila (grandchild/child).
Do dolphins chew their food?
Dolphins are a toothed whale which eat their food whole and head first. Their teeth are only designed for grasping food not chewing.
Why do dolphins look at you sideways?
Whales and dolphins have fantastic peripheral vision however can not see directly in front of them as their eyes are on the side of their head.
Do dolphins use their sense of smell like Polar bears?
Dolphins and whales can not smell as they have neither olfactory nervous system nor a nasal cavity.
