A man is being questioned by Dunedin police in relation to the killing of 30 protected red-billed gulls at the Royal Albatross Centre car park last month.
CCTV footage showed the gulls were killed as two cars and a quad bike hooned around the car park for about three hours, on February 6.
Senior Sergeant Craig Dinnissen said a person of interest had now been identified and was being spoken to.
At this stage in the gulls' breeding season in the evenings up to 1000 chicks congregated in the car park and it was only a matter of luck that more birds were not killed, Langsbury said.
The gull colony at Taiaroa Head had grown significantly over the past 10 years — increasing by 1000 pairs — and was the only red-billed gull colony in New Zealand that was not declining.
Whether the drivers were intentionally targeting the protected species or not, the entire headland was a seabird colony, he said.
Years of conservation work supported not only Dunedin's northern royal albatross and the red-billed gulls but more than 20 species of seabirds, he said.
"A young male is helping police with their enquiries."
Otago Peninsula Trust ecotourism manager Hoani Langsbury and Department of Conservation staff were pleased the police investigations were progressing.
Langsbury said staff at the centre were distressed when they arrived at work to find the dead birds, empty beer bottles, and extensive tyre marks throughout the parking lot.
At the time, it was the gulls' breeding season, and in the evenings up to 1000 chicks congregated in the car park.
It was only a matter of luck that more birds were not killed, Langsbury said.
The gull colony at Taiaroa Head had grown significantly over the past 10 years — increasing by 1000 pairs — and was the only red-billed gull colony in New Zealand that was not declining.
Department of Conservation ranger Colin Facer called driving over and killing adult birds and chicks both "clueless" and "gutless".
Red-billed gulls were more threatened than the northern royal albatrosses that breed on the peninsula, he said.
Those responsible could be prosecuted under the wildlife act, he said.