Different definitions of species presence to refine estimates of local species richness

Abstract

To improve predictions of spatial and temporal patterns of species richness it is important to 19 consider how species presence at a site is defined. This is because this definition affects our 20 estimate of species richness, which should be aligned with the aims of the study, e.g. 21estimating richness of the breeding community. Here we explore the sensitivity of species Innovation 25We use opportunistic citizen science data of high density (a total of 151,817 observations of 26 77 wetland bird species; i.e. about 16 observations per day) to build site-occupancy models 27 calculating occupancy probabilities at a high temporal resolution (e.g. daily occupancies) to 28 derive probabilistic estimates of seasonal site use of each species. We introduce a new way 29 for defining species presence by using different criteria related to the number of days the 30 species are required to be present at local sites. We compared patterns of species richness 31 when using these different criteria of species inclusions. 32 Main conclusion 33While estimates of local species richness derived from high temporal resolution occupancy