An orca that died on Mangawhai Beach may have drowned and Northland orca expert Ingrid Visser is concerned for the lactating whale's orphaned calf.
Dr Visser is hoping results of a necropsy will determine exactly how the orca died, but, with no obvious signs of damage to the whale, which was in "pristine condition", she believes it may have drowned.
An orca can drown if its blowhole is covered and she said, as orca don't have much flexibility in their neck, she would not have been able to lift the blowhole out of the water, as she was found on her side.
"It's a real tragedy when any orca dies like this, but she was lactating - we could see the milk coming out while she was lying there and it was really sad - and she has a wee baby out there somewhere," Dr Visser said.
The calf could be aged between a few weeks and 18 months. She said there had been reports of an orca pod in Whangarei Harbour and at Waipu Cove this week and it was possible the dead orca was a member of that pod, but she wouldn't know for sure until she examined photographs of the pod.