Prothonotary warbler, Rondeau Provincial Park, Ontario, Canada, May 20, 2018
This goes way past a bad hair day.
A mouth full of moss and his head disappeared. Using it to line a new nest in a tree cavity.
For Prothonotary Warblers it pays to be bright. Males that are brighter yellow gain access to better nest sites than less colourful males, according to a study conducted in Louisiana.
source - https://www.allaboutbirds.org/guide/Prothonotary_Warbler