Chicken feathers

I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University. Similar to my friend Sarah, I decided to investigate the birds in my backyard. The chickens frequently leave behind hints of their presence, from feathers to droppings to scattered feed. For many reasons, I decided to focus on their feathers. Most of the ones I could find were quite small, like so:

A commonly found chicken feather, with straighter parts near the tip of the feather and fluffier parts near the bottom.

While a few were longer and looked sturdier:

A longer chicken feather that looks like a quill.

What do these 2 kinds of feathers look like under the microscope? I decided to find out.

First, I looked at the first kind of feather, which has both fluffy and straight parts.

It was interesting how the same feather showed very different patterns. The fluffy pieces (maybe down?) look thin and disorganized – possible helps with insulation/keeping heat in? Whereas the straight pieces are very regular, with clear parallel stems (?) and even thinner pieces coming off of each stem. They might even be interlocking! Maybe this helps with repelling water/dirt?

Now, comparing to the second kind of feather:

Unfortunately these pictures weren’t as clear, but the straight lines are definitely more similar to the straight parts on the 1st feather than the fluffy parts. An interlocking/criss-cross pattern is also sort of visible here. This 2nd type of feather is probably on the outside of the chicken – maybe from the tail? – so it’s possible that this feather is more involved in forming a physical barrier to water/dirt than creating insulation to keep the chicken warm.

Overall, a pretty cool look at the chickens! I’m now wondering whether the feathers on a chicken might change in response to environmental variables. Will a chicken grow feathers that have more fluffy/down-like parts in the winter? Or is the feather pattern more predetermined, and chickens have some other way of adapting to different weather conditions?

A chicken.

One Comment Add yours

  1. Manu Prakash says:

    What a fantastic post – and a graceful chicken!

    You might also enjoy reading my old post on bird forensics from wing structures – probably a structure on which a lot of evolutionary pressure exists:

    This is a method commonly used to decipher what birds might have hit an airplane around the world!


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