Mature Oak Trees Holding Winter Leaves - December 2021

Yesterday, I posted some photos of our Frans Fontaine Hornbeam hedge (eight trees) that are still clinging to their leaves as we head into December.  One of the known features of those trees is that they hold their leaves longer than most trees - something called foliar marcescence.  Oak trees do something similar - in that if you look around right now and see large, mature trees with leaves on them, they're very often Oak trees.  

Last year, I posted a photo in mid-November showing the pair of mature Oak trees in our backyard that had - by then - dropped all of their leaves.  This was unique as I remember the Oaks holding their leaves deep into Winter.  I wanted to document what these two trees looked like this year - in early December.

Here, below, is a look at both of the trees (and other parts of our backyard canopy).  The large Northern Red Oak on the right (the tree swing) has leaves up and down the main trunk and branches.  The other mature Oak (on the top left) has none.  

My tracking of these trees and when they drop their leaves over the years:

• In early December 2021, the tree swing had leaves but other mature Oak was bare.
• In late November 2020, both of the trees had dropped ALL of their leaves. 
• In early December 2019, both trees were holding A LOT of brown leaves. Of note, this was a Mast Year with an abundance of acorns.