Saving birds from windows. many birds are injured or killed by flying into windows. it appears that birds don't see windows. can tilting windows down so that they reflect earth rather than sky reduce bird strikes? researchers placed six windows at the edge of a woods: two vertical, two tilted 20 degrees, and two tilted 40 degrees. during the next four months, there were 53 bird strikes, 31 on vertical windows, 14 on the 20 degree windows, and 8 on 40 degree windows. foes the tilt have an affect? state the null and alternative hypotheses.