Clues in a Photo

"Last week at dawn and dusk, there were well over 20 hummers coming and going at the feeders...no adult males.  This week there are usually around 15 at dusk.  There are several juvenile males showing off a hint of red.  It's interesting because some are chubby, some thin, some have long tail feathers, and some have short, stubby tail feathers." Treesa also noticed that two hummers were sharing a port at her feeder in Joplin, Missouri.

What details in Treesa's report might help identify the ages of the hummers she saw? What do you see in the photo that shows how Treesa helps protect her hummers against the colder night temperatures?

Photo: Treesa Morris