Tradition: a new reason to feed urban pigeons (Columba livia, Columbiformes: Columbidae), and how to control them in a sustainable way". Introduction: The rock pigeon, Columba livia, is considered a pest in many cities around the world, where people feed them in parks and control measures have mostly failed; however, they also provide entertainment and income to people. Objective: To identify the reasons why humans feed pigeons, the type of food and their perception of the problem. Methods: We worked in eight urban recreation parks of Costa Rica (total: 59 visits). From July to September 2017 we interviewed 161 people feeding pigeons and 90 who were in the parks but did not feed them. Results: People fed them scraps from their own food or, preferably, if they were sold for the purpose, seeds. The reason why people said they fed pigeons was independent of age, academic level and visit purpose (contingency chi square tests, all: p>0,01). One of the reasons was tradition; other reasons were "for fun" and empathy; men were more focused on empathy than women. Most people who fed pigeons did not consider them a pest and were uncertain about any need for control. Non feeders mostly considered them pests that need to be controlled. Almost everyone found contraceptives acceptable. Conclusions: A sustainable strategy for urban pigeons would include controlled food sales and contraception, instead of prohibition or extermination; this is the first time that tradition is found as a reason for feeding pigeons anywhere in the world.