The following page contains the walkthrough for the "Helping Harold" side mission in Marvel's Spider-Man.
Mission's starting location: Chinatown
Reward: 1500 XP after catching all the pigeons, unlocking of new side activity.
When in Chinatown, you may encounter Howard, who has a certain problem - his pigeons are gone. While sending Spider-Man on such a quest might be considered over the top, Peter has no reasons not to help. From now on, you can track the winged fugitives and catch them - in all, there's a dozen birds on the loose that need to be caught.
Catching the pigeons follows a scheme - once you get to a designated location, you'll see an escaping bird. Catching them is not that simple though - they are quick, fly between the buildings and love to turn. It's best to place yourself high above them and drop directly on them (ever seen Cameron's Avatar?), when you can press L1+R1 for Spidey to safely grab them.
For each captured pigeon you will be given 1 research token.