Banding Hummingbirds

Banding hummingbirds needs a steady hand and special training. Some weigh as little as 2.5g.
The tiny bands are cut with nail scissors from the sheet shown below, according to the size of the bird, and shaped and filed by hand.

 The help of some magnification is needed to read the bands of retraps.

 
 Some species caught at Madre Selva included White-throated Mountain Gem

 Green Violet ear

  Purple-throated Mountain Gem

and Fiery-throated Hummingbird

 Difficult to catch the stunning colours of the fiery gorget on camera 

The bills of young hummingbirds show striations ( growth marks)along the edge of the upper mandible. As the hummingbird gets older, the bill gets harder and smoother, and these bill striations disappear. So the percentage of striations on the bill is recorded and used to help age the bird.

Rufous feather edging on the head and upper parts is  another clue in separating  hatch year hummingbirds from adults in many species.