Field testing two individual marking methods for land snails, including description of a new PIT-tagging method.

This article focuses on the development and field application of two novel individual marking methods for land snails—fluorescent plastic "alpha tags" and passive integrated transponder (PIT) tags—used in conservation studies of the critically endangered Poecilozonites bermudensis in Bermuda and the endangered Allogona townsendiana in British Columbia, Canada. Alpha tags are small, fluorescent microtags glued externally to the shell, facilitating nocturnal detection, while PIT tags are inserted into the umbilical cavity of the shell, allowing internal, non-protruding identification via handheld scanners. Field results showed that alpha tags could be used on smaller snails, including juveniles, but experienced variable tag loss rates, whereas PIT tags had minimal loss and enabled effective detection, though their use is limited to larger snails with an open umbilicus. The combination of both tagging methods is recommended to monitor tag retention and improve individual recognition in gastropod conservation and ecological research.