A taxonomic, geographic, and temporal assessment of local birds in Portuguese ornithological collections

Since the birth of modern science, natural history collections (NHCs) have constituted the world’s largest repositories of long-term biodiversity data, making them essential to modern-day research. As part of an ongoing project aiming to review the Portuguese zoological collections in the country’s NHCs, we collected and analyzed bird data from its three major museums and two smaller collections to study coverage and representation of the taxa known from Portugal. Our results show that the collections are not taxonomically, geographically, or temporally complete and present considerable biases. Approximately 90.5% of birds are represented in the collections, but 85% are represented by fewer than 50 specimens. Geographic representation is also biased, as the country’s NHCs cover 41.7% of its territory. Thirty-one percent of the species are considered threatened or regionally extinct, yet account for only a little over one-fifth of the specimens extant in the collections. Here we present a review of the status of Portuguese bird collections, as well as a call to attention to the potential impacts on research resulting from such biases and subsequent gaps.