Your average squirrel is only worth about 400 calories, but will sure make that pot of rice taste a lot less bland.
Stock .22 rifle ammunition, and be prepared to pay a bounty on every fresh squirrel, rabbit, gopher, or whatever a bit of hunting can easily provide.
And our 6 hens have laid over 950 eggs so far this year...
For a while I was catching 2-4 squirrels a week with traps in the backyard, that might be an option also. Traps have the advantage of not requiring you to actually be there for them to work. A trapping license was suprisingly cheap, too.