Observations on the behavior of Anguispira alternata and Zonitoides arboreus under natural and laboratory conditions.

Abstract

While stumbling around in the Gorge one fine day in June looking for a gastropod problem, one was found that after a month and a half still remains unsolved. I noticed a decaying mossy log with several large snails on it. A few days later, I marked several of them with white enamel, and when I checked the next day some of the snails there were marked and some were new. Several similar logs were checked, but none were found to be nearly as populous. Questions arose: What attracted the snails to this log? Is the aggregation a function of the snail species or of the log? Did they remain on the log for an extended period of time or did they come and go? What were they doing when they were there?