Can Sea Lions’ (Zalophus californianus) Use Mirrors to Locate an Object?
Skip to main content
eScholarship
Open Access Publications from the University of California

Can Sea Lions’ (Zalophus californianus) Use Mirrors to Locate an Object?

  • Author(s): Hill, Heather M.
  • Webber, Krista
  • Kemery, Alicia
  • Garcia, Melissa
  • Kuczaj, II, Stan A
  • et al.
Creative Commons Attribution 4.0 International Public License
Abstract

Although California sea lions (Zalophus californianus) are capable of forming complex mental concepts, they have failed to demonstrate mirror self-recognition, a skill that requires both a mental representation of one’s physical features and knowledge of a reflective surface.  Many non-human species that do not recognize themselves in mirrors can nonetheless learn to use mirror reflections to locate and retrieve objects.  A total of 7 sea lions housed at 2 separate facilities were tested on their ability to detect an object using a mirror.  The results of a preliminary detection task in which sea lions were reinforced for looking at a mirror to locate an object suggested that 4 sea lions reliably learned to locate an object positioned below a mirror in one of three locations.  A follow-up study was conducted to determine if 3 different sea lions could learn the task without training the animals to use the mirrors.  Two of the 3 sea lions located a single object in 1 of the 3 locations statistically above chance when the mirrors were added to the task for the first time.  With additional mirror exposure, 1 sea lion successfully achieved 100% accuracy in detecting familiar objects placed in 1 of 3 familiar locations.  This sea lion also demonstrated her ability to detect an object via a mirror located in a novel, fourth position with 100% accuracy.  When two novel objects were tested with four locations, the sea lion again performed well, detecting the objects 87.5%.  The results suggest that sea lions have the ability to use mirrors to locate an object with minimal exposure to a mirror, but likely need additional experience with mirrors to efficiently use the properties of these reflective surfaces and understand that the image is a two-dimensional representation of a three-dimensional object.

Main Content
Current View