Portuguese terrestrial mammals in Portuguese Natural History Collections: an assessment of their taxonomic, geographic and temporal patterns

Natural History Collections (NHCs) constitute the world’s largest repositories of long-term biodiversity datasets and are fundamental in tackling the questions of modern science, amongst which is species conservation. To do so, NHCs rely on specimen collection and voucher deposition, which, in recent decades, have seen a drastic decline. As part of an ongoing project to review the Portuguese zoological collections in the country’s NHCs, mammal data from its three major museums and smaller collections were compiled and analysed to understand the coverage and representation of the different taxa extant in Portugal. We found that the collections are not taxonomically, geographically or temporally complete. Approximately 86% of Portuguese mammalian species are represented in the country’s NHCs, but more than two-thirds of the taxa are represented by less than 50 specimens. Geographically, the collections cover little over 40% of the country’s territory and more than half the occurring taxa have less than 10% of their known distributions represented in the collections. A third of the taxa represented in the collections is considered threatened, yet only accounts for 15% of all specimens. A review on the status of Portuguese mammal collections is presented here, as well as a call to attention on the implications of incomplete collections towards fundamental research.