More dog feces in the winter?

Why is it that I see more dog feces along the sidewalk during the winter months? I do not have a scientific data to prove this but there just seems to be more dog feces that the dog owners did not pick up. Is it because there are shorter day light during winter so people walking their dogs do not bother to pick up the feces in the dark? Since nobody can see them clearly in the dark? Is it that it is just too cold to be out long that picking up the dog feces is time consuming and they fore go the task? Is it that the snow can easily hide the dog feces that picking it up is unnecessary? Is it because the cold weather keep those feces frozen so the ones not picked up remains intact longer giving the illusion that there are many? I do not know. What ever the reason, those dog feces are just gross and annoying. To top it off, the cold weather preserved the feces for weeks. Decomposition can not take its course. Such is the thing I see whether true or not.