Because they don't know the words!
Obviously.
 |
| Tyrian metaltails |
 |
| White-bellied woodstar - male |
 |
| White-bellied woodstar - female |
 |
| Chestnut-breasted coronet |
 |
| Glowing puffleg |
Hummingbirds really do know the words, they just hum because they beat their wings so rapidly (12-80 times per second)!
All photos were taken Guango Lodge, at 2700m in the cloud forest on the eastern slope of the Andean Mountains in Ecuador.
