Mid-summer has passed and with it the morning serenade by the various birds nesting in my yard has come to a close. The young birds have grown and left the nest and there is no need to protect a nesting territory…so the birds shut up!

Not every species has finished nesting. Goldfinches for example. This species uses thistledown for nesting and the thistle seeds as a major food source. Generally, they nest in July and the young hatch in August when the thistle seeds are ripe. However, goldfinches don’t nest in my yard, and they are never part of the morning serenade.

With the ending of the nesting season you have the beginning of the molting season. Some birds molt once a year, some twice. Goldfinches are one species that has two molts.

Molting is the losing of the old feathers and the growing of new ones. In the case of the goldfinch, at the end of summer all the bright yellow feathers are lost and the bird takes on a dull grayish-brown color over the winter. The next spring it will drop the old brown feathers and grow the new bright yellow ones readying itself for breeding.

Feathers have to be dropped and re-grown because, like our hair, once fully formed they are dead material! Birds have different kinds of feathers. They have down, which coats the body in a fluffy blanket-like layer that keeps the bird warm. Covering the down are contour feathers. These are like the shingles on a roof. They overlap to form a waterproof barrier keeping the down dry. They are also streamlined for flight, and it is the contour feathers that give the birds their color.

The wings have flight feathers and the tail has similar feathers. These feathers have three main parts. The “shaft” which is embedded in the skin, the “afterfeather”, which is downy-like and is between the shaft and main part of the feather, which is called the “vane”. The vane is made up of secondary vanes with barbs. These barbs interlock like Velcro and give the feather its semi-solid structure.

The barbs can become unlocked and the bird has to take its beak and “preen” the barbs back into their interlocking position.

Like our hair, feathers have to be conditioned if they are going to last. In mammals we have a number of “sebaceous glands” that produce an oily substance that coats the hair. This oil attracts dirt and hence we need to wash periodically. The same is true of feathers; they too have an oily covering to keep the dead feather soft. Like our hair, the oil on the conditioned feather attracts dirt. The bird then has to “bathe” in your birdbath or take a dirt bath called “dusting”. The dirt soaks up the oil and then the bird shakes the oily dirt off. Next the bird has to take oil from its single oil gland called the “uropygial” gland, which is located on the back at the base of the tail. Using its beak the bird collects the oil and coats the feathers. More preening.

However, like our hair, even well-conditioned feathers eventually start to decay and wear out and so they have to be shed and new ones grown…molting, and now is the molting season.