Biologists: I understand that Antarctic killer whales cooperate when hunting seals. A large seal weighs 1000 lbs. A full grown killer whale needs around a thousand lbs of meat per day. How do they share a kill?

Where on earth are you getting that figure? According to every reasonable source I've found (whalemuseum.org, seaworld.org, iere org) they need more like 200-500 pounds of food a day. Specifically, they need about 2-4% of their bodyweight. A *massive* male might weight 11 tons and eat nearly 750 pounds of food a day, but literally the largest male on record was 11.1 tons or ~22,000 pounds. Most male whales never reach that maximum size and on top of that females are smaller. A generous average weight as far as I am aware is about 6 tons or 12,000 pounds requiring about 480 pounds of food per day. More likely around 300 pounds is a more reasonable estimate. Additionally, they don't just eat seals. They also prey on southern mink whales that weight several tons themselves. Also remember that they aren't solely making one kill a day. Heck, Ross Sea Whales eat almost soley fish. And ocean fish get *big*, with antarctic cod, a species that ross sea whales particularly favor, reaching about 300 pounds. From one source, it is also notable that males typically don't share food nearly as much - only about 15% of the time and typically with their mothers. That means that the whales sharing food are often the females, which as we establish trend towards smaller bodyweights. How they share food is a bit more complicated. It is established that young are favored, in the very least, by their mothers. Other then that... I don't know of any clear patterns? It does seem, however, that orcas have tried to share food with humans multiple times. Which is extremely interesting.