Ohh. Boy , there is a reason that Pigeon Patrol does not use Birds of Prey as a deterrent. This is reason one!

HAWKS were brought in on contract to scare away the pigeons. The parliament was warned the birds of prey could lead to a PR disaster if they began eating the pigeons alive in front of schoolchildren.Pigeon Patrol Hawk

But the birds or Prey had a closer call in when a “service agreement” document carried instructions to clear pigeons from part of the MSP block, then added: “Shoot pigeons if possible during first visit; if not, a second visit may be required.”

Early attempts to combat the problem by stringing anti-pigeon wire across ledges failed because they just hopped over it. Anti-roosting spikes were first rejected as “visually unattractive”, but later installed.

So this is the answer Kill the birds with another larger bird or Shoot them!!

Thank goodness Pigeon Patrol offers Pigeon or Bird Spikes, Bird Netting, 4-S Gel and Ultrasonics Sound Units to deter the birds!!