Species traits influence the process of biodiversity inventorying: a case study using the British butterfly database

1. The description of how biological information is compiled over time is essential to detect temporal biases in biodiversity data that could directly influence the utility, comparability, and reliability of ecological and biogeographical studies. 2. We explore trends in species recording over time using one of the most spatially and temporally comprehensive country-level databases for any group of insects in the world – the database of butterfly occurrences from Great Britain. 3. Firstly, we used two crucial milestones (the year in which the taxonomic inventory is complete, i.e., when the last species was recorded, the year in which all species are recorded together for the first time) to delimit three main phases in the process of biodiversity recording (taxonomic, faunistic and exhaustive phases). Secondly, we aimed to quantify how far species features (attractiveness and detectability) influence the process of recording through time. 4. During the first stage of biodiversity compilation, when the main aim is to complete the taxonomic inventory (taxonomic period), entomologists tend to record attractive species more frequently. However, once the inventory is complete, particularly in the period during which more spatially and temporally comprehensive information about species distribution is amassed (the exhaustive period), the recording pattern clearly changes to more detectable species. 5. Common, highly detectable species are undersampled in the first phase of biodiversity data compilation and oversampled in the final stages. Awareness of such temporal patterns in recording is necessary in order to correctly interpret and address bias in insect biodiversity trends.