As soon as humans learned to use simple tools then hunting and trapping would become relatively easy. If you can throw a stick you can take rabbits, squirrels, and birds. If you can sharpen a spear you can take porcupines and fish. If you can dig a pit you can take large game. Omnivores eat anything they can get their hands on and keep eating it until its gone. The idea that they only killed one deer per season is ludicrous. Native American hunters took a deer or similar sized animal once a week. Moreover, low fat game such as rabbit and deer are high protein with high levels of healthy CLA (a fat which prevents heart disease and cancer). Even Inuit who dined on high fat arctic game avoided heart disease because of EPA and DHA which are healthy omega3 fats.
Crab Eating Macaques
Diet: Crab eating macaques have the habit of inserting their hand in small burrows or holes to find crabs or other animals. In the mangrove swamp they have learned to feed on crabs, crustaceans, shellfish and other small animals exposed by the low tide.