23 January 2012 Last updated at 01:18 ET

Dozens of pilot whales beach in New Zealand

Volunteers were able to help many of the whales swim away

A group of 90 pilot whales have beached on a spit at the northern tip of New Zealand's South Island - the second incident in the area this month.

The whales in Farewell Spit, Golden Bay, are being kept cool by conservation staff.

Officials are hoping that the whales will be able to refloat themselves when the tide rises in the evening.

Seven whales died in the same area earlier this month when 25 of them were stranded.

"We generally get one stranding a summer and we occasionally get two, but since I've been here in the past 10 years, we've never had three," regional conservation area manager John Mason was quoted by the New Zealand Herald as saying.

The whales were spotted by an aircraft pilot while flying over Farewell Spit, he added.

In November, 47 whales also died in the same area when a pod of 65 got stranded.

Pilot whales - which are mammals and belong to the dolphin family - can grow up to 20 feet and weigh up to three tons.

Scientists do not know what causes mass beaching of whales.

They are most common in New Zealand in the summer, when whales pass by on their migration to and from Antarctic waters.