Pigeons need a happy life

The Guardian encourages weight-watching for pigeons:

"Pigeons have been bred for endurance flying, so when food is around they'll eat a lot of it so that when they do have a long flight, they'll have fat resources to draw on," he explains. "The problem is if there's always food available and they don't have to fly great distances, they will just lay down the fat."
And, of course, the podgy pigeon has few alternative means of exercise at his disposal. It is very difficult to master an exercise bike when your legs are only about two inches long. Yet despite the health risks, the pigeon population is thriving on junk food. The Pigeon Control Advisory Service (Picas) claims there is a 10-15% increase in flocks whenever a fast-food joint opens. "Pigeons adapted to cities instead of cliff faces," says Guy Merchant, director of Picas. "And now they've adapted beautifully to this new food source."
Williams begs to differ: "They are not designed for this sort of diet, but they can still get along with it. In the same way as you might say of us humans, they can survive. But it's not going to give you, or them, a long-term, happy life".