Bears have a natural life span of up to three decades, and some species can have a home range of thousands of miles. According to the International Zoo Yearbook, "[I]t is recognized that bears are extremely difficult and challenging creatures to manage in the captive environment"—just as challenging, according to studies, as primates.
http://www.peta.org/b/thepetafiles/archive/2012/09/25/bears-behind-bars-peta-asks-feds-to-help.aspx?utm_campaign=1012%20Bears%20Behind%20Bars%20Blog&utm_source=PETA%20E-Mail&utm_medium=E-News