While not necessary and it could be considered a luxury, I find having a band-it tool to be very convenient at times. You can find a used one on eBay for as low as $30 not including bands and clamps.
It is just an 8"x8"x14" piece of a beam that was found in a scrap pile. I added the banding after it split from hitting in the same spot one too many times.
The point is that butterflies are trying to deter birds that would fear predators. I doubt that hawks or owls would be deterred by something they do not naturally fear (ground dwelling predators).