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Dolphin FAQ

Why do Chinese white dolphins choose to live in Hong Kong?
As Chinese white dolphins are found of estuarine fishes, and the western waters of Hong Kong is at the Pearl River Estuary, Chinese white dolphins can be found in the western waters of Hong Kong. In fact, Chinese white dolphins (formally named Indo-Pacific Humpback Dolphins) in other places also live in estuaries.

Why are Chinese white dolphins pink?
As Chinese white dolphins live in estuarine environment with murky water, they evolved with a pale colour for better protection. Adults are basically white in colour. However, as their blood circulates well when they move around, they became pinkish. At times when they are not so active, they appear to be whiter. Chinese white dolphins that are dead are basically white.

Why do dolphins jump out of water?

Scientists infer that, there are a few possible reasons for this:
- frighten the fish and make them dizzy, making it easier to prey on them
- for fun
- to communicate with friends
- to get rid of parasites on the body
- to have a clearer view

How can we tell if a dolphin/whale is male or female?
In most case, it is quite impossible to distinguish between a male and female dolphin from the appearance. It is because their sexual characteristics are hidden within the genital slit. Yet, when you see an adult dolphin accompanying a baby dolphin, that dolphin should be a female. In dolphin’s world, only the female will take care of the young.
Yet, for some species, the male is much bigger than the females and their dorsal fin look different. For instance, male sperm whales are much bigger than female in the size of the head and dorsal fin. The dorsal fin for male pilot whales are much larger and lobe-shaped than that of female. Similarly, the dorsal fin of male orca (or killer whale) is much taller than that of females.
The one nearer is a male pilot whale, while the one further away is a female

The three in the front are female orcas, while the one at the back is a male

How do dolphins sleep? How long do they sleep?
Dolphins have to keep half of their brain awake so that they can get to the water surface to breath. Only half of their brain will have rest while they sleep. When dolphin get rest, it is common to find them resting in a group so that they can keep an eye on each other. Those that are resting will be in the center of the group while others in the outer circle will be on guard.
Yet, even scientists may find it hard to answer the question on how long dolphin sleep.

Dolphins look almost the same. How can we distinguish them?
If you look carefully, you will find every one of the dolphins is unique. Scientists distinguish dolphins by the difference in shape or notches position of their dorsal fin or tail, scars, body pattern, etc. When they carry out research, scientists usually take photos of the dolphins, create a photo catalogue and give them numbers to help them distinguish the dolphin in the wild, count their numbers in a certain place and collect information on the habits of individuals.

What do dolphins eat other than fish?
Most toothed whales feed on fish. However, apart from fish, some of them (e.g. Risso’s dolphins, pilot whales, etc) are fond of cephalopods like squids. Scientists also found food like shrimps in the stomach of dead whales (e.g. finless porpoises).
Baleen whales mainly feed on krills, planktons and small fish. They swallow a large volume of sea water and filter out their food with baleens.

Why do dolphins always look as if they are smiling? Are they always happy?
The smile on dolphin’s face is a result of evolution in millions of years. Millions years ago, the ancestors of dolphins lived on land and they looked like a wolf. Scientists believe that at a certain point, these dolphin ancestors started to live in waters due to the lack of food supply on land. They evolved with various characteristics that enable them to live in the sea, e.g. a streamlined body, nostrils (or blowhole) on the head and silkily smooth skin.
Although dolphins look as if they are always smiling, that does not mean they are always that happy. Dolphins are highly intelligent animals and they are sensual beings capable of emotional changes. For instance, dolphins captured from the wild will feel sad for they were being kept in a small tank, away from their friends and family and the vast ocean. In fact, many dolphins refused to eat after being captured and kept in a small tank. Not long after, they died from malnutrition or illness.