I've seen it in the news web-site. It was used interchangeably with word макак-резус.
What is also interesting, in the same article they first decline both words like "самец макака-резуса" and then completely separate the word макак and use it as a first class citizen word. So, the second related question is weather it is a correct way to decline this compound word.
резус макак
is a loan translation ofRhesus macaque
. Such loanwords are widely used in science butмакак резус
looks like illiteracy to me.