Searching for the Haplorrhine Heterotherm: Field and Laboratory Data of Free-Ranging Tarsiers.

摘要: The observation of heterothermy in a single suborder (Strepsirrhini) only within the primates is puzzling. Given that placental-mammal ancestor was likely heterotherm, we explored potential for primate closely related to Strepsirrhini. Based upon phylogeny, body size and habitat stability since Late Eocene, selected western tarsiers (Cephalopachus bancanus) from island Borneo. Being sister clade Strepsirrhini basal Haplorrhini (monkeys apes), hypothesized C. bancanus might have retained heterothermic capacity observed several small strepsirrhines. We measured resting metabolic rate, subcutaneous temperature, evaporative water loss percentage heat dissipated through evaporation, at ambient temperatures between 22 - 35°C fresh-caught wild animals (126.1 ± 2.4g). also core free-ranging animals. thermoneutral zone 25 30°C rate 3.52 0.06 W.kg-1 (0.65 0.01ml O2.g-1.hr-1). There no evidence adaptive either laboratory data or data. Instead, appeared be cold sensitive (Tb ~ 31°C) lowest temperatures. discuss possible reasons apparent lack tarsiers, identify putative heterotherms Platyrrhini. document our concern vulnerability future temperature increases associated with global warming.