title: Early brain growth cessation in wild Virunga mountain gorillas (Gorilla beringei beringei).
abstract: Understanding the life history correlates of ontogenetic differences in hominoid brain growth requires information from multiple species. At present, however, data on how brain size changes over the course of development are only available from chimpanzees and modern humans. In this study, we examined brain growth in wild Virunga mountain gorillas using data derived from necropsy reports (N = 34) and endocranial volume (EV) measurements (N = 86). The youngest individual in our sample was a 10-day-old neonatal male with a brain mass of 208 g, representing 42% of the adult male average. Our results demonstrate that Virunga mountain gorillas reach maximum adult-like brain mass by 3-4 years of age; adult-sized EV is reached by the time the first permanent molars emerge. This is in contrast to the pattern observed in chimpanzees, which despite their smaller absolute brain size, reportedly attain adult brain mass approximately 1 year later than Virunga mountain gorillas. Our findings demonstrate that brain growth is completed early in Virunga mountain gorillas compared to other great apes studied thus far, in a manner that appears to be linked with other life history characteristics of this population.
authors.affiliation: Department of Anthropology, Center for the Advanced Study of Hominid Paleobiology, The George Washington University, Washington, DC 20052, USA.
authors.forename: Shannon C
authors.initials: SC
authors.lastname: McFarlin
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Barks
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Tocheri
authors.forename: Jason S
authors.initials: JS
authors.lastname: Massey
authors.forename: Amandine B
authors.initials: AB
authors.lastname: Eriksen
authors.forename: Katie A
authors.initials: KA
authors.lastname: Fawcett
authors.forename: Tara S
authors.initials: TS
authors.lastname: Stoinski
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Hof
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Bromage
authors.forename: Antoine
authors.initials: A
authors.lastname: Mudakikwa
authors.forename: Michael R
authors.initials: MR
authors.lastname: Cranfield
authors.forename: Chet C
authors.initials: CC
authors.lastname: Sherwood
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D000835:Animals, Wild; D001921:Brain / Q000254:growth & development*; D015023:Democratic Republic of the Congo; D005260:Female; D006071:Gorilla gorilla / Q000254:growth & development*; D008297:Male; D012432:Rwanda; D014454:Uganda