Northern Flicker started to cry a lot

[Ally]

Hi everyone. I have two Northern Flickers hang out on the dead tree beside my place a lot.
They were usually very quiet. The day before yesterday, one of them started to cry lot. I recorded it, can anybody help explaining why? Thanks,
https://youtu.be/wCcXD0_ncc4  
Ally

[Kris Ito]

This sounds like one of the Northern Flicker's normal call sounds. I don't think you need to worry that they are "crying" - just communicating! Here is a link to some sample sounds from Cornell: https://www.allaboutbirds.org/guide/Northern_Flicker/sounds

[Ally]

Thank you. I was surprised, because for many days, they were so quiet.