title: Call cultures in orang-utans?
abstract: BACKGROUND
  Several studies suggested great ape cultures, arguing that human cumulative culture presumably evolved from such a foundation. These focused on conspicuous behaviours, and showed rich geographic variation, which could not be attributed to known ecological or genetic differences. Although geographic variation within call types (accents) has previously been reported for orang-utans and other primate species, we examine geographic variation in the presence/absence of discrete call types (dialects). Because orang-utans have been shown to have geographic variation that is not completely explicable by genetic or ecological factors we hypothesized that this will be similar in the call domain and predict that discrete call type variation between populations will be found.
  
  
  RESULTS
  We examined long-term behavioural data from five orang-utan populations and collected fecal samples for genetic analyses. We show that there is geographic variation in the presence of discrete types of calls. In exactly the same behavioural context (nest building and infant retrieval), individuals in different wild populations customarily emit either qualitatively different calls or calls in some but not in others. By comparing patterns in call-type and genetic similarity, we suggest that the observed variation is not likely to be explained by genetic or ecological differences.
  
  
  CONCLUSIONS
  These results are consistent with the potential presence of 'call cultures' and suggest that wild orang-utans possess the ability to invent arbitrary calls, which spread through social learning. These findings differ substantially from those that have been reported for primates before. First, the results reported here are on dialect and not on accent. Second, this study presents cases of production learning whereas most primate studies on vocal learning were cases of contextual learning. We conclude with speculating on how these findings might assist in bridging the gap between vocal communication in non-human primates and human speech.
authors.affiliation: Anthropological Institute and Museum, University of Zurich, Zurich, Switzerland. sergewich1@yahoo.com
authors.forename: Serge A
authors.initials: SA
authors.lastname: Wich
authors.forename: Michael
authors.initials: M
authors.lastname: Krützen
authors.forename: Adriano R
authors.initials: AR
authors.lastname: Lameira
authors.forename: Alexander
authors.initials: A
authors.lastname: Nater
authors.forename: Natasha
authors.initials: N
authors.lastname: Arora
authors.forename: Meredith L
authors.initials: ML
authors.lastname: Bastian
authors.forename: Ellen
authors.initials: E
authors.lastname: Meulman
authors.forename: Helen C
authors.initials: HC
authors.lastname: Morrogh-Bernard
authors.forename: S Suci Utami
authors.initials: SS
authors.lastname: Atmoko
authors.forename: Joko
authors.initials: J
authors.lastname: Pamungkas
authors.forename: Dyah
authors.initials: D
authors.lastname: Perwitasari-Farajallah
authors.forename: Madeleine E
authors.initials: ME
authors.lastname: Hardus
authors.forename: Maria
authors.initials: M
authors.lastname: van Noordwijk
authors.forename: Carel P
authors.initials: CP
authors.lastname: van Schaik
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004272:DNA, Mitochondrial / Q000235:genetics*; D005828:Genetics, Population / Q000379:methods; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D007858:Learning; D057079:Pongo / Q000235:genetics / Q000502:physiology; D013060:Speech / Q000502:physiology; D014828:Vocalization, Animal / Q000502:physiology
chemical_list: D004272:DNA, Mitochondrial