Happy Feet may have come to a not-so-happy end, but the penguin's advocates are defending the money spent on him.
After months of specialist care, and tens of thousands of dollars of donations, the emperor penguin's transmitter stopped sending a signal on Friday.
He had been fitted with a satellite transmitter from animal tracking company Sirtrack, and wildlife telemetry consultant Kevin Lay said data had not been received since Friday morning, when Happy Feet had travelled 115km in a southeasterly direction from his release point.
It was possible the transmitter, attached to his feathers with superglue, had fallen off.
Although this was not uncommon when tracking penguins, the company had believed the device would remain on Happy Feet for the next few months before he moulted.
"The other possibility that no-one wants to think about is that something in the food chain bigger than Happy Feet had him for a meal. That's what makes the world go round."
The transmitter had been working perfectly, sending strong signals and showing no sign of electrical faults before the signal suddenly disappeared.
Conservation Department Kapiti biodiversity programme manager Peter Simpson, who was on the penguin advisory committee that established what to do with Happy Feet, said he could still end up at a penguin colony in Antarctica one day and people should rest assured he had been returned to his natural environment.
Mr Simpson stood by the decision that had been made to remove Happy Feet from Peka Peka beach.
Releasing him had been the right thing to do, and Happy Feet had helped raise public awareness about wildlife.
"It's learning about the natural world, it's not about singing, dancing penguins."
Te Papa terrestrial vertebrates curator Colin Miskelly said it was hard to know whether or not the awareness Happy Feet raised would be transferred to other species or conservation issues.
Though it might never be known what happened to Happy Feet, he had been given better opportunities than penguins in the natural world.
"There are bigger things out there with bigger teeth."
Wellington Zoo vet Lisa Argilla said Happy Feet was an ambassador for his species and had raised awareness of conservation issues around the world. "That makes every cent spent worthwhile."
- The Dominion Post
Which would you prefer?Related story: Natural burials the way to go
The cost of losing nature