Also note that in this storyline these were not pigeons that were bred, but that rather they were wild or feral pigeons being fed by someone who liked their presence.
All of these things are objectable from some angle. Domestic cats kept for sentimental purposes can become a problem for bird populations that are already under stress, but the sentiment 'aww poor little birds' also shows a rather odd relation to nature.
I want to tell people to get less sentimental and conflicted about these things, but that puts me against 95% of the human population, even on ET.