Whether orchids or mammals, insects or slugs and snails: nowadays there are a large number of animals and plants under observation. Researchers and dedicated activists work meticulously to record their distribution, count their numbers, and document every increase or decrease. Unfortunately, the collection of this data began only very recently. For this reason, it is very difficult for ecologists to assess how much biological diversity has actually been lost due to modern civilisation. The fact that the human impact on biodiversity is likely to be greatly underestimated is the warning sent out by an international research team headed by the UFZ in a recent study published in Scientific Reports.