How humming birds forage for nectar

Hummingbirds stake out a group of flowers that are producing nectar and then defend them, trying to prevent other hummingbirds from taking "their" nectar. The flowers they defend are like a trap line. The "owner" checks each blossom in a sequence, taking nectar when it is found and then moving on to the next flower in line. This behavior is called "traplining," in reference to how humans hunt beaver and other fur-bearing animals by setting out a large number of traps and them checking them in sequence at periodic intervals. Hummingbirds can learn how long they have to wait to get more nectar from the same kind of flower. So after emptying one blossom they visit others and don't return until they first has had enough time to replenish its supply of nectar.