The spectrum of injuries of the kept pigeons ranges widely: Many suffer from malnutrition, others have crashed against windows and broken their wings. But also a huge number has been injured by human influence like aversive conditoning that includes spikes, nets and hawks. But there's a far bigger aray of methods when it comes to people brutalize pigeons: While the pigeon in the left picture caught a string and strangulated his foot, the pigeon in the right picture had landed on a window-sill that was covered with so-called bird glue. By trying to free itself it lost lots of its feathers. Other people make a hobby out of killing pigeons, as Gudrun Stürmer tells. She had to deal with pigeons that had been hunted with darts, air guns or covered with gasoline and lit.