I have eaten many road killed (more injured then I have finished em off) birds, ducks and pheasants galore here. Shoot and eat rabbit frequently, even squirrel is on my menu. Pigeons too. All free, all considered pests, all lived truly free lives and eaten natural food.
Buy yourself a 70 quid airgun, a 30 quid scope, find a friendly farmer who needs his IT stuff doing and swap your time for his permission to use the airgun on his farm.
Sorted. Free meat.
NB it takes about 20,000 pellets to kill a cow!!!
NB PS Probably
Rats are NOT good to eat!