Halle/Saale, Fort Lauderdale. More than 100 years of observations in nature have revealed a universal pattern of species abundances: Most species are rare but not very rare, and only a few species are very common. These so-called global species abundance distributions have become fully unveiled for some well-monitored species groups, such as birds. For other species groups, such as insects, however, the veil remains partially unlifted. These are the findings of an international team of researchers led by the German Centre for Integrative Biodiversity Research (iDiv), the Martin Luther University Halle-Wittenberg (MLU) and the University of Florida (UF), published in the journal Nature Ecology and Evolution. The study demonstrates how important biodiversity monitoring is for detecting species abundances on planet Earth and for understanding how they change.