and as our reporter katja doee discscover, thatat'sot as eaea as it sosounds. rosamira: cocotton-top tamaran monkeys haveve a special significance for me. i ababsolutely lovove working h them. they're an especially y beautil species. and that enablbles us toenenere grgreateintererestn theirr preservation. reporter: you have to navigate your way through endless forests and amps to find cotton-to marins in the wild. extremely shy, they' the size of c cat andeighgh less than half a kilo. they livive highn ththe tr-tops, and are one of the mtt endadanger primamateon the planet.. rosamira: cotton-top tamarins are ononly found here in colbib. and onlyly in one partrticulart of the c caribbean regegion. in the 1960's and 1970'shehey were used en masseor aninima experimentnts, for studidies on bowel cancncer. back then, 20,000 to 30,000 of them w were exported to the u.. reporter: today, therere only arou 700000 coon-top tamarins still liliving in the e wil. rosamira g guillen used d to a zoo director, but then she sacrificiced her career r to p protect ththe species.