All good info here. Thank you! I really had my eyes opened with the comment above about stocking them three years ago, and not seeing any. I think I better develop a bit more relaxed attitude! At least I know they are staying deep enough that the kingfisher isn't getting them.

9 yr old pond, 1 ac, 15' deep.
RES, YP, GS, FHM (no longer), HBG (going away), SMB, and HSB (only one seen in 5 yrs) Restocked HSB (2020) Have seen one of these.
I think that's about all I should put in my little pond.
Otter attack in 2023