Mark-recapture with slugs

[markwilson]

Hi folks,
My name is Mark and I am new to the forum! I am a graduate student working on a slug in the UK. It is an arboreal species and spends practically all of its time on tree trunks. Over the last few months I have been using refuge traps (essentially a series of 25cm2 tiles placed side by side to form a band around the tree trunk) to collect specimens but during the summer I would like to get population size and density estimates for the species. I have successfully tagged the slugs in the laboratory using a flouescent dye which has had a minimal impact on survival. However, I am looking for some advice when it comes to mark-recapture. The slugs spend the vast majority of their time on tree trunks (no information has been published on home range or even daily range) so if I was to use mark-capture-recapture to estimate population size over a range of tree trunks, will my estimates be for the trees I sample, the woodland or just for the area of the trap? If I used ten adjacent trees would the population be for the area encompassed by the trees? Any advice would be much appreciated.
Thanks in advance
Mark
PS I intend to use a robust design i.e. 3 primary sampling periods separated by 2 weeks each. Within each of these periods I will have five consecutive days of tagging (my secondary periods).