What is culture? One simple definition might be: a distinctive behavior shared by two or more individuals, which persists over time, and that ignorant individuals acquire through socially-aided learning.
One of the main challenges with photographing the non-human animals at the zoo is shooting through glass. Sometimes you just can’t get an angle without any glare, but sometimes it doesn’t matter.
Chimpanzees have a lot to gain from climbing the social ladder. It now appears that lower-ranking male chimps strengthen bonds with their friends in high places by alerting them to some good eats.