GenTag: a package to improve animal color tagging protocol

The individual identification of animals by means of tagging is a common methodological approach in ornithology. However, several studies suggest that specific colors may affect animal behavior and disrupt sexual selection processes. Thus, methods to choose color tagging combinations should be carefully evaluated. However, reporting of this information is usually neglected. Here, we introduce the GenTag, an R package developed to support biologists in creating color tag sequence combinations using a random process. First, a single-color tag sequence is created from an algorithm selected by the user, followed by verification of the combination. We provide three methods to produce color tag sequences. GenTag provides accessible and simple methods to generate color tag sequences. The use of a random process to define the color tags to be applied to each animal is the best way to deal with the influence of tag color upon behavior and life history parameters.