Wisely stated form another site:

" Humans make moral choices, have spiritual lives, and can relate to God in a unique way. God chose to make some creatures for the benefit of others. Animals and humans are not equal in the eyes of God. God chose to create animals for us. "

I don't know the actual verse, but I'm almost positive it exists. The decision to treat animals with "humanity" is a manmade one. There is a definate hierarchy in the animal kingdom. Man rules the nest.
Every instrument, every voice, every sound in nature ... these are are all my private tutors ... 24/7 for free, and all I have to do is listen.