A rare bird is the latest casualty in a wave of deaths following an avian botulism outbreak.
Several birds have been found dead at the site in recent weeks, but it's the first spoonbill to be added to the list, Lyn MacDonald, New Zealand Bird Rescue Charitable Trust manager, says.
She describes the latest find as "really heartbreaking".
"It's just terrible. The spoonbills are quite rare and it looked like we were starting to get a group establishing themselves here."
Auckland Council is aware of the avian botulism, which occurs annually in shallow, warm water and says it is a natural occurrence.
Humans can't catch the disease.