Moko the dolphin had already won over humans at Mahia Beach, where she plays with swimmers in the New Zealand surf and pushes kayaks along with her snout.

Now the friendly bottle-nosed has shown her empathy for other species, by saving two whales from almost certain death after they became stranded.

Human attempts to guide the two pygmy sperm whales through a narrow escape route from the beach had consistently failed, and all seemed lost until the dolphin intervened.

Moko, a regular visitor to Mahia Beach on the east side of North Island, appeared to communicate with the whales before guiding them to open water.

Malcolm Smith, a field worker for the New Zealand Department of Conservation, said that he had almost given up and was contemplating killing the whales to prevent further distress, until Moko arrived.

“It was amazing,” he said. “It was like she grabbed them by the flipper and led them to safety. We worked for over an hour to try to get them back out to sea . . . but they kept getting disorientated and stranding again.”

The whales — a three metres (10ft) long female and her 1.5-metre male calf — had been unable to negotiate a sand bar that was blocking their way to deeper water.

Mr Smith was alerted to the whales’ plight early on Monday morning by a neighbour. “Over the next hour and a half I pushed them back out to sea two or three times and they were very reluctant to move offshore,” he said.

“I was reaching the stage where I was thinking, it’s about time to give up, I’ve done as much as I can. The whales were getting tired and I was getting cold when Moko turned up. She just came straight for us and escorted the two whales along the beach and out though the channel.”

He heard Moko and the whales making noises before they departed, he said. “The whales were on the surface of the water quite distressed. They had arched their backs and were calling to one another, but as soon as the dolphin turned up they submerged into the water and followed her.”

Moko led the whales 200m along the beach and once they reached the end of the sand bar, Moko turned a right angle through a narrow channel and led the whales to safety.

Rescued whales often return to the site of their stranding, but Moko’s actions appear to have had long-term success. “She obviously gave them enough guidance to leave the area because we haven’t seen them since,” Mr Smith said.

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