It's Esteban Sarmiento, primatologist and biologist.
Here's some info from the OBC website:
"Esteban Sarmiento is a primatologist and biologist and is noted for his work in primate anthropology and for appearing on the Monster Quest television series. Sarmiento earned a biological anthropology Ph.D. in 1985 and from then until 2008 he worked as a research associate at the American Museum of Natural History. His main field of study is the skeletons of hominoids, including both extinct and living species. From 2002 to 2004 he was a Fulbright scholar teaching physiology at Eduardo Mondlane University in Mozambique. Presently, he heads The Human Evolution Foundation whose main goal is to understand humanity's place in nature. Sarmiento is one of the few mainstream experts to give serious attention to cryptozoology, particularly reports of Bigfoot. Sarmiento does not suggest that the existence of Bigfoot has been established, but that its existence is possible and that claims and evidence deserve careful scrutiny. He has stated, 'If the animal in the P&G film is real, this animal is exceedingly human-like and would be our closest relative on earth.' He has appeared on several episodes of the History Channel series Monster Quest discussing Bigfoot and other 'cryptids.'"