Thomas R. Defler (born 26 November 1941; Denver, Colorado[1]) is a North American primatologist who lives and works in Colombia.
Defler then worked in the Amazonian Vaupés Department where he developed and lived in his research station, Estación Biológica Caparú until 1998.
He and the Colombian biologist Marta Bueno are credited with first describing Hernández-Camacho's night monkey (Aotus jorgehernandezi) in 2007.
[7][8][9] Using karyotypes, Defler has done work clarifying the taxonomy of various species of night monkey (Aotus).
[10] He has done field studies in the Colombian Llanos and the Colombian Amazon on the white-fronted capuchin (Cebus albifrons), the brown woolly monkey (Lagothrix lagothricha), the black-headed uakari (Cacajao melanocephalus), the black titi (Callicebus lugens), the Lucifer titi (Callicebus lucifer), and the Venezuelan red howler (Alouatta seniculus) and has accomplished many primate censuses in different parts of eastern Colombia.