Thanks to illustrator Mark Simmons -http://bit.ly/mark-simmons_oakland-zoo-elephants -- I can say that these are probably Lisa (37 in 2014), on the left, and Donna (35 in 2014) on the right, whom the Oakland Zoo pages say are closely bonded and sleep together at night. ... The zoo also says that Donna, the dominant elephant in the group of 4 is the most playful, and Lisa is called "water baby" because she loves her pool. ... Here's Lisa enjoying a bath in her water pool:http://bit.ly/lisa-in-pool at the 8-acre area they can roam.