Down by the river

I made a quick diversion off my cycling route home to find something blippable in the diminishing light. As I neared the riverbank a pair of mallards frightened by my presence skittered out across the river disturbing the surface of the water from its gentle flow. Wild garlic (1st extra) is starting to come through the nutrient rich earth and tastes delicious. Had the creature which left this footprint eaten the contents of the discarded shell? (Extras 2&3)