When referring to primate brain size and its relation to social intelligence, scientists at Duke University do not think the answer is a simple yes or no. The mouse lemur and the indri. There are more than 30 different species and dozens of subspecies of lemurs, ranging in size from the 1 ounce mouse lemur, to the 20 pound Indri. The visual cortex is clearly delineated (white arrows) by the dark and patchy appearance of the CO staining. Mouse lemurs have one of the smallest brains among primates, and absolute brain size increases from mouse lemurs over ring-tailed lemurs to ruffed lemurs (Isler et al., 2008). Lemurs are woolly-furred, long-tailed, arboreal animals that are found only on the island of Madagascar off the Eastern coast of Africa. The researchers observed more than 120 captive primates in … The relationship between brain size and body size continues to tempt and vex attempts to identify the role of cognition in primate evolution. (C) Size comparison of a mouse lemur brain (left) and a rat brain (right; scale bar, 5 mm). frugivores) have larger brains than leaf-eating species (a.k.a. We examined the relationship between group Brain size size, pairbonding, and relative brain size in a sample of 19 lemurs; strepsirrhine primates that last share Sociality a common ancestor with monkeys and apes approximately 75 Ma. Ring-tailed lemurs are diurnal opportunistic omnivores that live in groups of on average 14 individuals ( Gould, Sussman & Sauther, 2003 ; Jolly, 1966b ; Sussmann, 1991 ). Instead, only body size and diet explain primate brain size variation – larger bodied species have larger brains, and fruit-eating species (a.k.a. an extinct lemur, with a skull larger than a gorilla's, that lived on Madagascar. A recent study examined the relationship between brain size and the development of motor skills across 36 primate species. Besides the obvious size difference — the human brain is about three times larger than the chimp brain — … folivores)! In primates, a large brain size to body size ratio has been associated with a variety of advantageous attributes such as prolonged life span (8), deception (9), and cultural/social intelligence (10). Does size matter? (B) A mouse lemur climbing on a branch. Relative to body size, primate brain size: is larger among great apes than among other primates. represent the range of sizes in living lemurs, though extinct lemurs … Even mouse lemurs… These patterns are depicted in the plot below. Megaladapis. Lemurs perform a range of physical domain challenges as part of the Primate Cognition Test Battery at the German Primate Center (DPZ). (D) Cytochrome oxidase (CO) staining of a flat-mounted mouse lemur cortex.