what effect did the birds death have on byron?

Byron starts throwing cookies at a bird sitting on a telephone wire. One hits the bird right in the chest and the bird falls to the ground, dead. Kenny is astonished that Byron managed to hit the bird, but Byron is uncharacteristically horrified, so horrified that he throws up. Byron insists that it he has simply gotten sick from eating apples from the apple tree, and tells Kenny to scram; he does, but comes back later and sees that Byron has made the bird a little grave and buried it.