An Air New Zealand spokeswoman confirmed a flight from Auckland to Wellington scheduled to depart at 6pm was delayed by around 35 minutes while an alternative aircraft was found.
"The aircraft originally scheduled to operate the service required additional cleaning following a spill from a customer's hand luggage."
She did not confirm the story the spill was caused by the dead bird.
A Southerner familiar with the muttonbird harvest informed the Herald that no one would transport muttonbirds with blood in them, and that the liquid was most likely brine or pickle.
"The birds are salted which draws the blood out. The blood dissolves in the pickle. It may appear to be blood but it's not. And if they're in a bucket, which they were said to be, it would be 20 birds and not one. They're very small."
The incident became referred to as "blood plane" in the Twitter thread with one commenter saying everything was fine as long as [The Mutton Birds lead singer] Don McGlashan was okay.
The Mutton Birds were a New Zealand band in the 1990s famous for hits including Anchor Me and Nature.
The muttonbird, or tītī, are the plentiful sooty shearwaters that nest in New Zealand and the islands in the South Atlantic Ocean.
The seabird has the flesh of a bird but tastes like fish because of its diet. Rakiura Māori have rights to gather muttonbirds on 36 islands, known as the Tītī Islands, around Stewart Island. They can harvest chicks each year from April 1 to May 31 under the Tītī (Muttonbird) Islands Regulations of 1978, says the Te Ara Encyclopedia of New Zealand.
Chicks have been described as remarkably fat with the name muttonbird coming from early setttler accounts in Norfolk Island describing the meat as resembling mutton.