Tim Anderson final balanced rock stack in the Llano River. Tim Anderson, rock balancing “pro” from Pennsylvania, carefully worked to balance his stack on a dry spot in the Llano river Saturday March 12, 2016. He was an honored guest of the festival and enjoyed visiting Texas so he came for another year. The river was higher this year because of the rains so the balancers could not get to the better rock that were available last year. (Photo by Nell Carroll/American-Statesman)

Young people jump over a bonfire as they take part in the Ivan Kupala Night celebration, a traditional Slavic holiday, outside the small town of Turov, some 270 km south of Minsk, on July 6, 2016. People celebrate Kupala Night with bonfires that last throughout the night with some leaping over the flames as it is believed that the act of jumping over the bonfire cleanses people of illness and bad luck. (Photo by Sergei Gapon/AFP Photo)

Stefan Sigmund, 29, from the Transylvanian city of Cluj, attempt to smoke 800 cigarettes through a self designed device in less than five minutes, in central Bucharest Tuesday, January 30, 1996, trying to enter the Guinness Book of Records. It is the last of his several attempts entering the record book which included eating 29 hard boiled eggs in four minutes and leaping into a lake from a height of 41 meters (135 feet) even if the Guinness Book of Records no longer rewards self damaging attempts. (Photo by AP Photo/Stringer)

This photo taken on June 19, 2017 shows Indian yoga teacher Mahesh Yogiji attempting a world record for the longest yoga session in Ahmedabad, ahead of International Yoga Day on June 21. According to Guiness World Records, the longest yoga marathon undertaken by a man lasted 69 hours and was achieved by V Gunasekaran in Tamil Nadu in June 2016. (Photo by Sam Panthaky/AFP Photo)

An Indigenous man stands under a water fountain outside a government building in Brasilia, on April 26, 2019, during the last day of a protest camp. Approximately 4,000 indigenous people from different tribes are taking part in protests during the Indigenous National Mobilization (MNI) week, a mobilization which seeks to tackle territorial rights' negotiations with the government. (Photo by Carl De Souza/AFP Photo)

Job seekers carry a woman who fainted at the Indonesia Spectacular Job Fair 2015 at Gelora Bung Karno stadium in Jakarta August 12, 2015. Indonesia's gross domestic product grew at 4.67 percent in the second quarter, its slowest pace in six years. Since he took office last October, Widodo's government has passed a raft of measures aimed at boosting industry and consumption that have been criticized by investors as protectionist. (Photo by Reuters/Beawiharta)

A girl holds her newly purchased pet cat while posing for a photograph at a pet shop in Srinagar, the summer capital of Indian Kashmir, 10 November 2025. Kashmir is seeing more pet owners, especially of Persian cats. Over 6,000 cat bite cases were reported last year, accounting for nearly half of the rabies control budget. Experts urge vaccination as demand for pedigree pets continues to rise. (Photo by Farooq Khan/EPA)

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.