Monitoring near-entrance activity of burrow-dwelling invertebrates using an image analysis system

A computer image analysis technique is described for automatically estimating the activity of burrow-dwelling invertebrates. The rationale was based on the assumption that the in-and-out movement of a burrow-dweller is associated with a proportional variation in the luminance characteristics of the video image. The system was applied to analyze the activity of tube-dwelling hermit crab Discorsopagurus schmitti (Stevens, 1925) (Crustacea, Decapoda). The results obtained were consistent with direct observation of behaviors. The method is accurate and reliable, and could be of great help for the study of other burrow-dwelling invertebrates.