Most dogs go into heat 2x a year.(about every 6 months.)
Well they are all warm blooded but not all bear live young.(Platypus and Echidna)
If you want to feed birds in your yard I'd use some wild bird seed or old bread,popcorn,suet,leftovers even. I've seen them eat a variety of foods.
Puppys start early and can start breeding in about 6 months. The humping is a natural thing but keep enforcing the word NO and he should start listening