Diminishing growth of zoological natural history collections threatens future research in the life sciences and beyond

Natural history museums comprise a unique and important component of biological infrastructure worldwide, and underlie diverse research, education, and outreach in the natural sciences. Each museum is built around one or more biological collections that serve as a repository of important materials for study, which have contributed to scientific research in increasingly important areas ranging from understanding global climate change to developing new biotechnological applications. However, despite centuries of existence, global collections sizes have only been recently estimated, and aside from analyses of certain institutions or well-studied clades, little is known about how patterns of collecting activity across institutions, geographic regions, or taxonomic clades, or how these patterns vary across time. To address this important gap in our understanding of critical life sciences infrastructure, I gathered and analyzed zoological records associated with preserved specimens collected between 1900 and 2015 and housed in worldwide natural history collections using data from the Global Biodiversity Information Facility. My analysis indicated that global, museum-associated collecting activity focused on animals has varied greatly over time, peaking around 2000 and declining significantly since. By stratifying data by institution, nation, and taxonomic phylum and class, I also illuminated how individual data series contribute to these global patterns. Institutions and nations had either concentrated or dispersed periods of relatively high collecting activity that occurred over different time periods, although most growth occurred in the second half of the 20th century for both many individual institutions and globally. Certain taxonomic clades comprise the largest proportions of collections records over this time period, namely arthropods (especially insects) and chordates (especially vertebrates), underscoring the taxonomically biased collecting histories of many institutions. Altogether, my analyses provide a critical, early view of historical zoological collecting activity and, to help other museum stakeholders to explore the data and results in more depth, I also describe and release NHMinformatics, an interactive dashboard built using R Shiny. These resources, when combined with recommendations I have made for sustainable collections growth, will be helpful for establishing policy goals, provisioning museum infrastructure, and training curatorial personnel.