As to can birds be avoided in a commercial jet the answer is yes. I flew into Tegucigalpa, Honduras for seven years in a B757 and my number 1 concern was the thousands of turkey buzzards in the valley every day.
You have to give looking out the windscreen your ultimate concern below 3500 ft AGL. If you don't chances are you will hit one. They are everywhere. Even on final approach slow I have made major maneuvers to miss them knowing I may end up going around if I couldn't get back in the slot knowing how important it was not to hit one of those big birds. We had a couple of engines taken out by our company by flights but they can be avoided in most cases if you keep a vigilant lookout for them.
I have heard the posts saying it isn't possible, but it is possible to avoid birds with a commercial jet if you are looking for them before they fill up your windscreen.