Cougar Mountain Zoo 2009, Peter Rittler continued in the zoo's management. The zoo collection features 32 exhibits of animal habitats concentrating on endangered species such as tigers, lemurs, wolves, reindeer, cranes, wallabies, macaws, and cougars, among others. On June 16, 2007, the zoo acquired two male Bengal tiger cubs, a royal white and a golden, who were born eight weeks apart in a Florida tiger preserve. The zoo added an additional two cubs in 2009. A glass-walled tunnel called the "Tiger Tunnel" enables visitors to view tigers in close proximity. In 2011, a 370-pound (168 km) tiger was photographed holding his paw up
Hip replacement (animal) as human replacements were, historically, made—a metal (cobalt chrome or titanium) femoral component, and an ultra high molecular weight polyethylene acetabular component. Since animals have a shorter life than humans, their hip replacements can safely be assumed to be lifelong and will not wear out or need replacing. By contrast, human hip replacements are sometimes deferred until older, to avoid the possible need for replacement later on in life. Other treatments may give a good quality of life with fewer attendant risks. Surgery for dogs, as with humans, is a final alternative when non-invasive methods are unable to treat a