  Computer vision applications are increasingly popular for wildlife monitoring
tasks. While some studies focus on the monitoring of a single species, such as
a particular endangered species, others monitor larger functional groups, such
as predators. In our study, we used camera trap images collected in
north-western New South Wales, Australia, to investigate how model results were
affected by combining multiple species in single classes, and whether the
addition of negative samples can improve model performance. We found that
species that benefited the most from merging into a single class were mainly
species that look alike morphologically, i.e. macropods. Whereas species that
looked distinctively different gave mixed results when merged, e.g. merging
pigs and goats together as non-native large mammals. We also found that adding
negative samples improved model performance marginally in most instances, and
recommend conducting a more comprehensive study to explore whether the marginal
gains were random or consistent. We suggest that practitioners could classify
morphologically similar species together as a functional group or higher
taxonomic group to draw ecological inferences. Nevertheless, whether to merge
classes or not will depend on the ecological question to be explored.
