Let's start with pigeons' bad reputation for being “dirty” and for carrying all kinds of diseases. I’m not sure what being “dirty” actually implies in this case, but like most animals, pigeons groom themselves regularly, so they don't stand out in this respect. As for diseases, pigeons do in fact carry diseases that may be harmful to humans, including chiamdiosis, psittacosis, histoplasmosis, cryptococcosis, and a couple of others. Before passing judgment, we should remember that not only pigeons, but all animals, including our beloved cats and dogs, carry diseases which may be harmful to humans. In fact, cats and dogs carry more of these diseases than pigeons do. The vast majority of us do not get sick from our pets (or from pigeons) because it's generally not easy to catch a zoonotic disease (a disease contracted from an animal). Other humans are much more of a health risk to us than pigeons, dogs, or any other animals. Unless we have a heightened sense of hypochondria, we usually don’t get paranoid about this, so, logically, we should be even less paranoid about zoonotic diseases. This is not to say that we shouldn't try to minimize contact with pigeon droppings. Contact with any fecal matter, animal or human, is best avoided. The occasional bird dropping on our balcony or our car is just part of life, but if we want to prevent pigeons from congregating (and pooping) in certain areas en masse, there are more and less ethical ways of doing this. Poisoning them is both cruel and unethical. Apart from the fact that it is completely unnecessary to kill these birds, ingesting the poison makes them suffer greatly before they die. The humane way to solve the problem is to simply stop feeding them where we don't want them to gather. This will result in a win-win situation for both us and the pigeons. The birds will not congregate in an area where they know they won't find food, so we won't have to deal with their droppings, and, in the long run, the pigeons will benefit from having to seek food for themselves. After all, a lot of the food that we feed them with (bread for example) is not very good for them. Some people think that this inappropriate diet might be one of the reasons that 10 species of pigeon have become extinct since the 1600s, and that close to 60 surviving species are currently threatened with extinction.
In my opinion, we don’t give pigeons enough credit. They are actually pretty fascinating animals. First of all, like other birds, they are much smarter than we might think. Studies have shown that they can, in fact, remember and recognize human faces, and even have the ability to distinguish letters of the alphabet. Another interesting fact about them is that they are monogamous, usually for life. They’re also really good parents, and take care of their children until they are almost fully grown (which is why we rarely see baby pigeons). Pigeons get a bad rap, partly because they're so prevalent, and partly because we've been taught to believe a lot of negative things about them that are not necessarily true. A little bit of research does a lot to break stereotypes, and while you don’t have to suddenly start to love pigeons, I hope you use the information in this post to at least gain some insight and to try to coexist with them in a more positive way.
