Again, not exactly crowdsourcing, but it shows how lower organisms can use simple mechanisms to create collective action — in this case, respond to threats based on their size:
Many birds and mammals sound alarms to let others know they’ve spotted a predator. Some species even modulate their alarm calls, increasing the pitch or frequency depending on the size and distance of the attacker. Now, scientists have discovered that Asian honey bees (Apis cerana) also tune their signals to tell their hive-mates about the type and degree of danger and the context. It’s the first time that such sophisticated alarm signaling has been found in a social insect.
More at Science.
(Contributor: Haym Hirsh)