A new baiting scheme and simple method of rhodamine B detection could improve biomarking of small mammals

The success of group biomarking with rhodamine B (RB) is determined by two key stages—baiting and mark detection. This work has two objectives: (1) to examine the suitability of a new bait type and the proposed experimental procedures for marking small mammals with RB and (2) to evaluate the effectiveness of the new method of RB detection in field studies of small mammals. Uniquely designed bait with RB was placed in nine rectangular plots in forest stands. The experiments differed in the area of the marking plots, application rate of the bait, and the time interval before the start of animal trapping. Small mammals were captured and evaluated in a dark room for the presence of RB markings. A green laser with a diffuser was used as the illuminator to excite fluorescence, and orange glass was used for separation of the emission spectrum. The new method for the detection of RB was shown to be simple and reliable. The bait used in this study was proven to be effective and is potentially suitable for most species of small mammals, especially rodents, under certain conditions.