I visited here in 199? (early nineties anyway) and I seem to remember they had two at that time. I was hoping they might have a Sumatran but of course they didn't, just these instead.
I just had a quick google search. Two rhinos -- a male and a female -- came from Nepal on April 22nd 1986. The male was only eight months old at the time and died just three months after arrival. The female was eight years old and I guess is the one still at the zoo. On 12th December 1994 a male arrived at Chiang Mai from Singapore Zoo but I don't know what happened to that one. (Or it might be the opposite: the one at the zoo currently might be the Singapore male and the Nepal female has died).
I just had a quick google search. Two rhinos -- a male and a female -- came from Nepal on April 22nd 1986. The male was only eight months old at the time and died just three months after arrival. The female was eight years old and I guess is the one still at the zoo. On 12th December 1994 a male arrived at Chiang Mai from Singapore Zoo but I don't know what happened to that one. (Or it might be the opposite: the one at the zoo currently might be the Singapore male and the Nepal female has died).
I may be getting confused with the Elephants, there were two of those. The timeline of when they had two rhinos doesn't really fit for when I went so I probably only saw one then.