Elizabeth,

 

Just keep doing what you're doing.  Unfortunately you've chosen to rescue animals who are readily resupplied by society.  It's sort of like rescuing whole fryer chickens.  No matter how many you rescue, there will always be more.  So with that in mind, I give you the parable of the starfish, which fits in many cases, including this one:

 

"Most teachers know the story of the man who was walking along a beach at low tide, picking up a random starfish and flinging it back to sea, then bending over and repeating the process as he made his way down his little part of the coast.

He was approached by another man who had been watching the seemingly hopeless task of returning thousands of starfish to the safety of the ocean. The second man asked the first, “Why are you trying to save the starfish? Don’t you see it’s a hopeless task? You’ll never be able to save them all! What difference will it make?”

The first man bent over once again and picked up another starfish. “It makes a difference to this one. ” And threw it back to the ocean."

 

Robert