 For non-human primates outside the great apes, the evidence for mirror self-recognition has been sparse.  Gallup himself regards it as a phenomenon restricted to the great apes only, and he was among the first to challenge Hauser's report that cotton top tamarins engaged in mirror-guided self-directed behaviors after their distinctive white tufts had been dyed neon colors, a stimulus that Hauser and coauthors argued was presumably more salient than the red dot used by Gallup (Hauser et al. 1995).  Faced with Gallup's challenge, Hauser himself was unable to replicate his initial results (Hauser et al. 2001).  However, the idea that Gallup's protocol uses a stimulus that is not particularly salient to monkeys continues to have some currency. For example, Rajala et al. (2010) have presented quantitative and videographic evidence that rhesus monkeys with surgical implants in their heads use mirrors to inspect the implants, as well as other parts of their bodies that they cannot usually see.