Hector's dolphin is the only dolphin found solely within New Zealand waters. They are found around most of the South Island and are relatively common around Banks Peninsula. The dolphins are found closer to shore in summer than the winter. They are rarely seen further offshore than 5 miles and, in summer, nearly half their population is found within 800m of shore. This habitat, especially in the relatively low visibility waters of Banks Peninsula may offer some protection from their predators but is more likely to offer better fishing. These dolphins seem to prefer shallow water no deeper than 60 meters with poor visibility.
What do they do all day?
Feed, rest and play. Hector's dolphins of all ages spend a lot of time playing. They surf when seas are quite rough. In calmer weather a favourite game is playing with bits of seaweed. The dolphins also love to play around boats - there seems to be no other reason than just for the pure joy of it. As you will have seen it is a great social experience for humans and dolphins alike.
What do they eat?
Hector's dolphins feed mostly in small groups and are generalist feeders. They feed both at the water surface and at the bottom. They eat a variety of fish including squid, red cod, flatfish and yellow-eyed mullet. When feeding an average dive is 90 seconds but have been known to dive for 2 minutes. Hector’s dolphins eat about 4kg of fish per day. Like all dolphins, hector's use “echolocation” to find their food, sending out high frequency clicks and listening for returning echoes. The echoes can tell them how far away a fish is, what kind of fish it is and how fast it is moving.
Who eats the dolphins?
Seven gill sharks, blue sharks and Killer Whales are known predators of the dolphins, though the number of dolphins taken is unknown. By far the biggest threat to dolphins is that of human activity. The death rate among the calves is thought to be quite high. They have been known to drown in very rough seas or get hit by fast moving pleasure boats.
How often do dolphins give birth?
Females have their first calf between seven and nine years old, and give birth to one calf every 2-3 years. A female living to 20 years old may give birth to 4-6 calves. Most calves are born from early November to February. Mothers and calves can often be seen in small 'nursery' groups consisting of several females and their young calves. Young dolphins are not good swimmers. They do not dive deeply and their reactions are slow. Hector’s dolphins weigh about 9 kgs at birth and they are about 60cm long at birth. Calves are suckled on fat-rich milk for at least a year following birth, but they start eating their first solid food around six months of age.