Riot police fire tear gas during a protest by supporters of Dilma Rousseff in Sao Paulo, Brazil August 31, 2016. (Photo by Paulo Whitaker/Reuters)

Trucks loaded with tree trunks are burned by agents of the Brazilian Institute for the Environment and Renewable Natural Resources, or Ibama, during an operation to combat illegal mining and logging, in the municipality of Novo Progresso, Para State, northern Brazil, November 11, 2016. When able to do their job, agents of the Brazilian Institute for the Environment and Renewable Natural Resources, or Ibama, are decisive, punishing illegal loggers on the spot. Nearly twice the size of India, the Amazon absorbs an estimated 2 billion tonnes of carbon dioxide per year, making its preservation vital in the fight to halt global warming. (Photo by Ueslei Marcelino/Reuters)

Drum queen of the Unidos do Viradouro samba school Erika Januza performs during the first night of the Carnival parade at the Sambadrome in Rio de Janeiro, Brazil, April 23, 2022. (Photo by Amanda Perobelli/Reuters)

Zoo keeper Ross Poulter holds a White's Tree Frog in Edinburgh Zoo's new tropical forest zone on September 9, 2011 in Edinburgh, Scotland. The Brilliant Birds Exhibit which brings together beautiful and rare birds from all over the world is now more colourful and unusual, with the unveiling of the zoo's new tropical forest zone bringing together a collection of vertebrates, invertebrates and amphibians for the very first time. (Photo by Jeff J Mitchell/Getty Images)

This is a bearded tit bird, diving for food. Photo by Edwin Kats.

The battle by Jose Garcia, US. Category: bird behaviour. A great white heron (Ardea herodias occidentalis) fighting a green snake in the Florida Everglades. The fight lasted for nearly 20 minutes with the heron having to release its prey. (Photo by Jose Garcia/2017 Bird Photographer of the Year Awards)

Creative imagery, gold winner: Sprats and Bread, Ruediger Schulz, Germany. (Photo by Ruediger Schulz/2021 Bird Photographer of the Year)

Sharon Beals is a San Francisco based photographer who has photographed nest and eggs specimens collected over the last two centuries at The California Academy of Sciences, The Museum of Vertebrate Zoology, and The Western Foundation of Vertebrate Zoology. While few nests are collected today, these nests and eggs are used for research, providing important information about their builder’s habitats, DNA, diseases and other survival issues.