What do pigeons fear most?

Pigeons fear most things that represent predation, exposure, and being trapped, though as adaptable urban birds they can tolerate fear if food is abundant. Their biggest fears include natural predators like Peregrine Falcons, Cooper's Hawks, and other hawks and falcons that hunt them in flight and are fast enough to catch them, owls that hunt at night when pigeons roost, cats, raccoons, and snakes that can reach nests and roosting sites, and humans who chase, trap, or harm them. They fear sudden, loud, unpredictable noises and movements that signal danger, such as clapping, banging, and fast approaching people. They fear being cornered with no escape route, which is when they become most panicked and will fly erratically. They fear loss of safe roosting and nesting sites, because without sheltered ledges and lofts they are exposed to weather and predators. They fear starvation and dehydration, so lack of food and water is a major fear. They fear new, unfamiliar objects in their environment due to neophobia, so new deterrents like spikes or nets may cause initial avoidance. They also fear strong winds and storms that make flying difficult. Most of all, pigeons fear hawks and falcons, which is why they fly in tight flocks and take evasive action when they see a raptor silhouette, and why fake predator decoys like owl statues have some short-term effect though they habituate quickly.