UC Berkeley has all its eggs in one basket — all 50,000 of them.

One of the largest fossilized egg and nest collections in North America is housed at UC Berkeley’s Museum of Vertebrate Zoology and was recently used by researchers in a study to trace the evolution of egg shape.

The museum, hatched in 1908, contains nearly 50,000 egg specimen from about 1,400 species curated from North America, Europe, Asia and Africa, according to bird collection curators Rauri Bowie and Carla Cicero. The first specimen was collected for the museum in 1843, and since the museum opened its doors 65 years later, the collection has continually grown.

The origin of UC Berkeley’s egg collection dates back to the late 1800s, when people would often collect eggs as a hobby. The collected eggs were frequently donated to museums or found in private collections, according to Cicero.

“Lots of those private collections ended up in the museum, and now we have this large egg collection,” Cicero said.  

The smallest specimens the museum houses are hummingbird eggs, weighing just two-tenths of a gram, while the largest are the 9-kilogram eggs of the now-extinct elephant bird, according to the Museum of Vertebrate Zoology’s website. Though the museum is not normally open to the public, Cicero said an elephant bird egg will be on display during Cal Day.

The egg collection is often utilized in research projects, and most recently, it was used by researchers to discover why egg shapes vary between bird species in a study that was published in Science magazine and is now nominated for a Webby Award. The study suggests that birds adapted for high-powered flight have larger, longer eggs.

The eggs housed at the Museum of Vertebrate Zoology were digitally photographed and used to provide clear visuals for the study.

“Through our efforts to photograph all the MVZs eggs with the help of undergraduate students and funding from the National Science Foundation, enabling us to make these data freely available, a wonderful piece of science has been completed,” Bowie said about the study in an email.

Cicero said researchers previously needed to come to the museum to study the eggs, but now the images allow them to study the eggs remotely.

“We’ve gotten a large number of requests for studies also using digital images,” Cicero said. “There is a lot of information researchers can get off of the images.”

In the past, the egg collection has notably been used in researching the effects of a pesticide called DDT. By measuring the thickness of eggshells from times before and after DDT was used, researchers found that the pesticide was causing eggshells to thin, contributing to nest failure.

“UC Berkeley’s Museums and Field Stations provide invaluable opportunities for scientific discovery and learning,” Bowie said in an email, regarding the egg shape study for Science magazine. “The Stoddard et al. study provides a wonderful exemplar of the value of Berkeley’s collections to the national and international scientific community as well as the public.”