Hello--
I got a reply from the Cornell Lab of Ornithology on the issue of safety of feeding peanut butter to birds near nesting season. Here it is: "My first response to this dialogue was that it had no basis in science. But I thought I ought to check with someone who has scientific credentials, the head of our Project FeederWatch citizen science program, Dr. David Bonter. He says, "Don't believe everything you read on the Internet. To my knowledge, there is no evidence to believe or even suggest that feeding peanut butter to birds may lead to egg-binding." And we know that the birds really enjoy it, especially in the winter when their needs for fat are the greatest."
c wilsdon at earthlink net, Seattle