A 5m long orca called Eleven and a pod of his playmates have been cruising Whangarei Harbour feasting on eagle rays and stingrays.
After entering the harbour at about 2pm on Wednesday, the group separated into two pods in the shallow low tide on either side of the Snake Bank sandbar between McLeod's Bay and One Tree Point as they went hunting.
Orca Research scientist Ingrid Visser, alerted to their presence via the 0800 Seeorca (0800 7336722) hotline, was able to get out on the water to document the group's size, behaviour and identify some of the orca.
Eleven was easily identified by his size, his dorsal fin and "patchy" markings, Dr Visser said. "He's very tolerant. As long as you approach with respect he'll let you get within arm's length of him."
True to his nature, Eleven ignored the boat as he got on with the day's hunt, at one time even swimming underneath it.
Dr Visser, who has been researching New Zealand orca for 20 years said Eleven was 19-years-old and she had seen him many times.
Although a large male, he was not the leader of the pod of mainly females, she said. She described him as "a mummy's boy".
While at times they surrounded the Orca Research boat, the orca were not interested in the vessel and were not playing. "They're feeding in here for sure," Dr Visser said.
Those on board saw three orca chase a 1m long ray clearly visible in water so shallow their dorsal fins were sitting high out of the water like small black sails. Dr Visser said their bellies would have been scraping the sandy bed.
New Zealand is one of the few countries in the world where people regularly see orca from the shoreline and nowhere else are orca known to come into populated harbours hunting rays, she said.
Groups of the black and white orca move around New Zealand's coast and are not the same variety as the grey and white giants of Antarctic waters. This is the time of year orca are often seen in Northland.
"We've seen at least seven different groups in the last five weeks ... we would normally expect to see that number over a period of about two months."
While on the water, Dr Visser took several calls from people reporting the orcas in the harbour. She said she was grateful for all calls to the hotline.
"People often think someone else will have already called so they don't bother ringing and we sometimes hear nothing. Orca can travel 100 to 150km a day so every minute is critical."