“Bird Lover” wants to know why people are told not to feed the pigeons. When pigeons are overfed, they over-breed. Sometimes here in Chiang Mai, where “everyone” feeds the pigeons, I see very ill and dying pigeons that have trouble moving and are in obvious pain. I speculate that could be a symptom of overpopulation.
When there are too many pigeons, the city sometimes decides to kill them. So, if you really love birds, respect the city’s effort to control the pigeon population.