A pair of peregrine falcon parents are raising three chicks along Chicago’s busy Wacker Drive, and beware to any pedestrian who ventures too closely to their nest.Just ask Chuck Valauskas, who was struck by one of the falcons. The patent attorney was leaving work one day last week, walking below the nest situated on a seventh-floor ledge when he felt a thud on his head.“I thought, ‘What was that?’ It felt like a 16-inch softball,” Valauskas told the Chicago Sun-Times.He sustained a 1-inch gash …