Ooooh How the biologist in me loves questions like this.....

I'd also point out that there are lots of factors on this one. If you are feeding less, then yes, less poop. But also if you have cooler temps during this season, even if they are eating the same amount, metabolism slows. If you are pairing them then they will also likely use more energy to build/breed, which means less energy is available for other processes....

Cheers,
Kat