During an after lunch walk near the end of last January, I found and marked (with red ink) 8 live, but dormant, adults of a land snail, a Triodopsis species. These snails were at the same spot where I had collected roughly 300 empty shells of them several months earlier.
I returned at the end of February and marked, again with red ink, all the adults (25) I could find. On 17 April, I found 12 of those snails and remarked them with red ink. At the same time, I saw 9 unmarked adults, which I marked with green ink.
Yesterday, I went back. Expectedly, the place had changed quite a bit since April. There were now plants growing everywhere and one of the small boards under which some of the snails were taking refuge had been displaced. Back in April, I noticed that since the end of winter the snails had gotten more mobile and some had left their winter homes. Their increased mobility, of course, makes it more difficult to locate them.
Yesterday, the plant cover also made it difficult to search for snails, but I could still find 10 adults. None was marked green, but one was carrying its red line behind its lip.
Now I know for sure that the adults of this species survive the winter and some live at least until June. One day next week I will go back and carry out a more thorough search. I will also mark all the unmarked snails I can find with a yet different color.