It appeared that Happy Feet was destined for a storybook ending. Over the summer, the 3-year-old emperor penguin had strayed 2,000 miles off course before he was found in New Zealand, famished and stuffed with sand that he apparently ate thinking it was snow. After being nursed back to health at a zoo, Happy Feet was on his way home. But just days after being released back into Antarctic waters on Sept. 2, a GPS tracker glued onto his back — which signaled his whereabouts every time he surfaced — has gone silent. Yes, Happy Feet is missing. What happened to the "wayward" penguin? Here, three theories:

1. He was someone's dinner
Face it, says Britain's The Sun. The most likely explanation for Happy Feet's silence is that he was "eaten by a killer whale." Or a shark. Or a leopard seal. When the Wellington Zoo was fixing up Happy Feet (at a cost of $30,000), he gave "warm fuzzies" to animal lovers who saw him as a symbol of nature's resilience. But in the wild, predators merely saw him as a meal.

2. His tracking device just fell off
Cheer up, says veterinary professor John Cockrem, as quoted in the New Zealand Herald. Happy Feet is probably alive and well. Leopard seals, one of the penguin's natural predators, are found farther south than the area where Happy Feet was last pinpointed. His chances of meeting a killer whale in that part of the ocean are slim, too. "It is most likely the transmitter has fallen off."

3. Solar flares are interrupting Happy Feet's transmissions
Sirtrack, the company that has been keeping tabs on the penguin, might start hearing from him again, says the Sydney Morning Herald. The trackers say a satellite relaying his coordinates has been out of service due to "a spate of solar flares over the last four days." When the interference passes, there's a chance we'll hear from Happy Feet again.