Wet the bird's beak and watch him drink. As the water evaporates off of the beak, it condenses the gas inside. This causes the amount of liquid in the bird to increase and rise, throwing it off balance and dunking its beak in the water again. As the liquid in the bird changes back into a gas the bird rises and the process repeats.
Wet the birds beak and after a few moments he will start to drink.
