Patterns of Affiliation and Co -Operation in Howler Monkeys: An Alternative Model to Explain Social Organization in Non -Human Primates

This dissertation addresses questions concerning the evolution of primate sociality and factors that constrain the size, composition, cohesiveness, and interactions among individuals living in a social group. Although it has been suggested that feeding competition, aggression, and predator avoidance determine the size and composition of primate social groups, several recent studies of primate socioecology have highlighted the role of cooperation and affiliation in determining the costs and benefits of social grouping patterns. I conducted a detailed field study of subgrouping patterns, social affiliation, and ecology in two neighboring groups of black and gold howler monkeys ( Alouatta caraya) in Northern Argentina from April 2003 to December 2004. The study took place on Isla Brasilera, 290 ha, 27° 20'S and 58° 40'W in northern Argentina. I tested a series of hypotheses concerning how factors such as social dominance, individual spacing, feeding competition, changes in food availability, partner preferences, and the development of male-male, male-female, and female-female social bonds affect social subgroup size and composition, and mating patterns. My research indicates that this howler population is characterized by extremely low levels of within-group contest competition, limited within-group scramble competition, and no observed or suspected instances of infanticide in 7 years. Moreover, I found that affiliative relationships and partner preference remained consistent over time and across social contexts. Individuals were found to invest considerable time in affiliative social interactions such as grooming, huddling, cooperative defense, and were tolerant of the mating of activities of resident males and females. A main conclusion of this research is that social factors associated with a range of mating strategies including female promiscuity, cooperative male mate defense, partner competency, and individual friendships play a greater role in structuring black and gold howler social organization than female feeding competition and infanticide risk.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Anthropology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Kowalewski, Miguel Martin

Contributors dc:contributor

• Garber, Paul A.

• Biology, Zoology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3290280

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/85276