Interesting....I wonder if "she" was fat with eggs? One of my fish guys says YP will spawn in our area around Valentine's day, I'm going to look closely for egg cases in the next couple of weeks.
I've wondered if TS can survive in a pond populated with YP, they seem very able piscivores, and I would think they'd just run the shad to oblivion...apparently not so. What other fish do you have in the 1.5 a pond?