Szechwan (Pepper) hasn't been singing lately. Usually, he's very busy, and loud. I'd even consider him the dominant male in the Finsterium, with all the singing he does. But not lately. He isn't singing his Hunka Hunka Burning Love song, and he isn't building his nest. He's active otherwise, but not in these two important ways.
This could be due to a few things, or a combination of them. The weather is getting cooler and the daylight hours are getting shorter. He's a smart bird, and he may be taking a break now that it clearly isn't Mating Season. Or, he could be going through a molt, and is cutting back on other activities while that happens. He's so darned naked, it's hard to tell if he's molting or not.
Or, like Frank
, he may have stopped singing because he's nearing the end of his life.