Scientists say they have lost track of Happy Feet, the wayward emperor penguin who won hearts around the world after washing up on a beach in New Zealand.

A satellite tracking company said Monday it has received no signals since Friday from a tracking device that was glued to the bird's back before it was released into the Southern Ocean eight days ago.

Officials at Sirtrack say they suspect the glue failed and the device fell off, months earlier than they had hoped. But they could not rule out the possibility that Happy Feet has become a meal for some ocean predator.

The officials said there is a slim chance that solar flares have interrupted the transmissions and they will resume in the coming days. The transmitter only works when it is on the ocean's surface.

Happy Feet became an Internet sensation after being discovered in ill health in June some 4,000 kilometers from its Antarctic homeland.

Veterinarians painstakingly nursed it back to health, including several operations to remove sand and twigs from its digestive system. Thousands of fans monitored its progress by video camera from its pen at New Zealand's Wellington Zoo.

A fisheries boat finally released the 3-1/2-year-old bird on September 4 in an area near Campbell Island, where other juvenile emperor penguins are normally found at this time of year. Officials had hoped Happy Feet would join up with the other penguins for the long swim back to Antarctica.