Hunting gannets are in constant danger of killing each other in underwater collisions, extraordinary footage from a Kiwi-based researcher shows.

Massey researcher Gabriel Machovsky Capuska has been studying the Australasian gannet Morus serrator, found in 29 colonies around New Zealand's coast.

He has captured video which shows the high risk maneuvers the gannets execute while plunge diving for small fish and squid.

The footage shows fatal collisions during high-density feeding, when two gannets target the same fish and one pierces the neck or head of the other.


Post-mortems of two of 50 carcasses collected from Hauraki Gulf waters showed the gannets had died from collision injuries, Mr Capuska said.

"While this ratio suggests the phenomenon to be relatively rare, analyses of underwater video footage of Cape gannets in South Africa shows accidental collisions between gannets are not so uncommon."

Gannet colonies are at Muriwai on Auckland's West Coast and Cape Kidnappers on the East Coast near Napier are both popular tourist destinations.

- Herald Online staff