These specimens are a heterogeneous mixture of egg sets collected by both museum-based researchers and hobbyist egg enthusiasts mostly from the late 1800s to early 1900s. Despite their abundance in natural history collections worldwide, historic egg specimens are drastically underutilized in research on the ecology and evolution of avian reproduction. Unlike other types of specimens (such as study skins and cryogenically preserved tissues), blown egg shells are incredibly delicate and therefore difficult to ship on loan to scientists outside of the local institution. Through high quality imaging, the UMMZ is making its collection broadly accessible as both a scientific resource and a public identification and education tool.
Research-grade images of eggs must accurately capture color, pattern, and other aspects of morphology; achieving this requires very careful setup of the fragile shells. We use custom 3D-printed cups to hold the eggs in place along with a scale bar placed in-frame; this allows precise length and width measurements to be extracted from the photos (Image 1). We also use numerous coordinated flashes and diffusers to create a balanced light environment. Coupled with a professional color standard, this permits egg color and pattern data to be taken from the images (Image 2). Excitingly, our standardized approach renders the photos amenable to machine learning and AI processing for automated calculation of all of these features.
Our egg digitization project will facilitate scientific progress in a relatively understudied area of avian ecology and evolution. The evolutionary drivers of egg morphology and coloration is an exciting frontier of research. Furthermore, the vast majority of these eggs were collected before 1930, making them a critical resource for understanding trends in avian populations throughout the past century. For example, museum holdings of Peregrine Falcon eggs collected before and after widespread use of agricultural DDT famously demonstrated that the pesticide causes egg shell thinning and subsequent population collapse in birds of prey—what essential biological and conservation findings remain to be discovered in these beautiful specimens? (Images 3,4).
