Romina Pavé

An Ontogenetic Framework for Alouatta: Infant Development and Evaluating Models of Life History

This review investigates the ontogeny of the genus Alouatta, with the goal of determining whether howler monkey development follows a “fast-slow” continuum or whether individual life history features are dissociable from one another. Data indicate that while many aspects of howler life history are relatively accelerated compared to other atelines, a consideration of only the end parameters (e.g., age at weaning) obscures important variation within each trait. Moreover, sexual dimorphism in the pace and timing of Alouatta developmental events (e.g., somatic and craniodental maturation) provides support for a framework of life history dissociability. Based on these results, we propose a life history model for Alouatta ontogeny that recognizes that within the context of an overall rapid development, dissociabilities occur both among and within individual life history parameters.

How do demographic and social factors influence parent‐offspring conflict? The case of wild black and gold howler monkeys (Alouatta caraya)

In this study, we examined the influence of demography and social context on mother‐offspring conflict in wild black and gold howler monkeys (Alouatta caraya) inhabiting two nearby sites in northern Argentina, one comprising continuous forest and one fragmented forest. These sites differed in population density (3.25 vs. 1.04 individuals/ha), degree of home range overlap between neighboring groups (70 vs. 31%), and rate of intergroup encounters (2 vs. 0.02‐1 encounters/day), though not in interbirth interval or rate of infant mortality. During a 27‐month study (September 2008 through November 2010), we observed 37 mother‐offspring dyads across the two sites. We found a very similar pattern of mother‐offspring conflict in both populations; specifically, the sites did not differ in any of the variables used to characterize the mother‐offspring relationship (the time spent in contact, the rate at which the mother makes and breaks contact, the rate at which the infant breaks contact, the rate of maternal rejection, and signs of infant distress) except one (the rate at which the infant makes contact). Although mother‐offspring conflict is a dynamic process that varies over time, our results suggest that the different demographic and social contexts found at the two study sites did not have a marked effect on quantitative aspects of the mother‐offspring relationship in these populations of black and gold howlers. Finally, this study suggests that the environmental variability (ecological, demographic, and social traits) leads to a set of strategies used both by infants and mothers with a main goal of conflict resolution, with mothers specifically aiming to cope with the tradeoff between current and future reproduction. Am. J. Primatol. 77:911–923, 2015.

Nectar Feeding on an Exotic Tree (Grevillea robusta) by Alouatta caraya and Its Possible Role in Flower Pollination

Several species of primates consume nectar and/or pollen (Sussman, 1979; Torres de Assumpcao, 1981; Puertas et al., 1992; Peres, 1994; Carthew & Goldingay, 1997; Birkinshaw & Colquhoun, 1998; Passos & Kim, 1999; RibaHernandez & Stoner, 2005; Marin-Gomez, 2008). Nectar is a high-energy resource and an important food source for mammals living in habitats with marked seasonality (Janson et al., 1981; Garber, 1988; Ferrari & Strier, 1992). Also, mammals including primates can be possible pollinators of different plant species (Kress et al., 1994; Carthew & Goldingay, 1997).

Social play among black and gold howler monkey (Alouatta caraya) immatures during intergroup encounters

We studied intergroup social play (IGSP) among immatures in wild black and gold howler monkeys (Alouatta caraya) in northeastern Argentina. IGSP events are one form of affiliative interaction that can occur during intergroup encounters. The main goal of this study was to analyze IGSP in A. caraya immatures and assess how intrinsic (e.g., age and sex) and extrinsic (e.g., seasonality) factors can influence the development of this type of social behavior. We followed 12 groups between 2008 and 2015 and recorded 182 encounters and 61 events of IGSP. Considering the composition of play partners, most IGSP events occurred among juveniles of both sexes (33%), followed by juveniles that were only‐male (31%), and finally between mixed‐sex juveniles and infants (20%) interactions. Additionally, most IGSP events occurred mainly in summer (56%), followed by spring (29%), with fewer events occurring in autumn (15%) and no IGSP events recorded in winter. Our results suggest that IGSP constitutes a beneficial activity in wild A. caraya that promotes behavioral flexibility, where immatures acquire social skills, such as tolerance, by interacting with unknown individuals. Moreover, the higher participation of young males in IGSP is consistent with the fact that adult black and gold howler males tend to be more actively involved in group encounters than females, supporting the hypothesis that social play provides benefits in the development of motor and social skills. Finally, seasonality in the frequencies of IGSP might be related to availability of foods with high and easily mobilized energy content in summer and spring.