Hawks favor insects for their caloric needs, except during nesting season. During nesting season, hawks need the extra calories and seek out small critters, including mice, rabbit and, naturally, squirrels. This hawk in Jersey City's Lincoln Park had the right idea as it flapped into a tree to find some food. However, food was not to had as a squirrel leaped out of the branches to avoid a lunchtime fate.
Obviously, this squirrel had some hawk-evading training that included a "Game of Thrones"-style mantra: "What is the one thing we say to hawks? 'Not today.'"