National Geographic : 2017 Jul
Lift Airflow Downstroke 100% of the lift Upstroke 0% of the lift Downstroke 75% of the lift Upstroke 25% of the lift Bee hummingbird 1.7 inches long Common pigeon 11-14 inches long Elbow Wing tip Actual size Lentiformis mesencephali .25% Percentage of total brain volume Part of the brain Lentiformis mesencephali .07% Hippocampus 4% Hippocampus 7% Hand wing is around 75% of total wing area top view top view Wrist Hand wing Arm wing Elbow Shoulder Hand wing is around 50% of total wing area ArmwingHandwing Shoulder Wrist Motion detection The motion-sensing lentiformis mesencephali (LM), larger than in other species, is believed to help with stabilization while hovering. A hovering hummingbird rotates its wings between the upstrokes and downstrokes, making a figure eight motion. Sharp memory Thanks to a large hippocampus, a hummingbird remembers the location of flowers in its territory and knows when they’ll refill with nectar. Powerful wrists A hummingbird’s small arm wing allows wrist motion to control a larger area of the wing, leading to a more powerful upstroke. MONICA SERRANO, NGM STAFF; MESA SCHUMACHER. ART: VLAD RODRIGUEZ SOURCES: CHRISTOPHER CLARK, UC RIVERSIDE; DOUG ALTSHULER, UNIVERSITY OF BRITISH COLUMBIA; ANDREW IWANIUK, UNIVERSITY OF LETHBRIDGE, ALBERTA Their larger LM allows hummingbirds to respond with more sensitivity to motion from all directions. Pigeons’ LMs, like those of most vertebrates, respond mainly to motion from behind, since it could be a threat.