Don't Audubon and Lee Richardson also have sun bears? Also if they are being phased out why did Saint Louis build a fantastic state-of-the-art exhibit less than two years ago?
I don't think sun bears are being phased out among all AZA institutions, merely at Columbus. As others have commented, the sun bear population is far from self-sustaining and without importation of new stock and/or vast improvements in captive breeding, there is likely to be an effective phase-out of the species as there will be few specimens left to populate exhibits. It's sad to me that AZA institutions seem to have such difficulty maintaining viable captive populations of bears: while there is no shortage of rescue individuals of brown and American black bears, sloth bears are not doing extremely well, Asiatic black bears are almost entirely gone, polar bears continue to face a well-discussed lack of breeding success, and pandas are understandably never likely to be established, leaving only Andean bears (and even there, I'm not sure how successful AZA institutions are).
I'll miss the sun bears if and when they leave Columbus, but I must admit that they didn't fit as well into the outdoor Asia Quest exhibits (which, with the exception of the silvered leaf monkeys, are entirely populated by temperate Asian species). Originally the sun bears were announced to be part of the Islands complex, where they might have fit better.
As to replacements for the sun bears when they leave, I agree that Amur leopards would work (with substantial changes to the exhibit, of course), but to my knowledge, Columbus shipped off the two Amur leopards that formerly inhabited the top floor of the sun bear indoor quarters. With a leopard exhibit still present in Congo forest section (albeit home only to a lone female who must be getting up in years), I'm not sure that Columbus needs another leopard subspecies at present (though when the remaining leopard passes, I'd prefer not to see Amur leopards placed in an otherwise African section, which is what I had feared was the plan when the two Amurs were around). Snow leopards could work, but there was a plan to repurpose the old lion exhibits (now home to surplus Amur tigers and the younger mountain lion sibilings) for snow leopards. Other Asian bear species could work, although, as noted above, Asiatic black bears (the best fit) are not available and sloth bears are not overly abundant (and are a less suitable geographic fit). Giant pandas (if available - there have occasionally been whispers that Columbus would add them, even though those rumors have never been very credible or feasible) work in terms of theme, but the exhibit is wholly unsuited for the display of such a marquee species. I'd love to see something unusual and underrepresented in AZA collections take the space - raccoon dogs, though I fully recognize they are almost non-existent in AZA collections at present and unlikely to be phased in.
Anyone have any other thoughts? Next time I visit I'll see if I can gather any intelligence on what might be coming....
. Why are they being phased out?