How Much Fat?

Body fat is a good measure of how healthy a hummingbird is, and how well it is eating. A hummingbird's skin is thinner than a plastic sandwich bag, and just as clear. Under the skin fat is whitish yellow, which shows up easily against red muscles. Nancy holds the hummimgbird upside down (there is more fat on the underside than the back) and blows on the chest feathers. When the feathers part, she can see the skin and how much fat is there.

Checking Fat
Nancy uses a regular drinking straw to gently blow on a hummingbird's underside.
Blowing makes the feathers fly up, showing the skin and the muscles and fat.
It's tricky to blow and look through a magnifying glass at the same time. Nancy's had lots of practice.
Can you see little whitish fat deposits under this hummingbird's skin?


Next: Weighing the Hummingbird