Adult male replacement and subsequent infant care by male and siblings in socially monogamous owl monkeys (Aotus azarai)

Abstract

Owl monkeys (Aotus azarai) are small, territorial, socially monogamous primates that show intense infant care by the adult male in the group. It has been hypothesized that male care may be adaptive because it increases offspring survival and/or reduces the metabolic costs to the female of raising the offspring. Alternatively, males may provide care even when they are not related to the infants to increase future reproductive opportunities. We describe changes in infant care patterns that took place following the eviction of the resident male by a solitary male in an owl monkey population in the Argentinean Chaco. The resident male and mother provided all infant care during the first month of life of the infant, until the male was evicted. During the 3-day male replacement event, care of the infant was shared among the mother, a 4-year-old sister, and a 1-year-old brother. The new male began contributing to infant care soon after entering the group, carrying, and interacting socially with the infant in much the same way as any male regularly does. However, despite receiving biparental care from both the original and new resident males, the infant disappeared at the age of four months and was presumed dead. These are the first reports of care by sibling and by non-putative fathers in wild owl monkeys. Given the significant amount time that new pairs of owl monkeys spend before reproducing, it is possible that male care in owl monkeys functions as mating effort as much as or more than parenting effort.

When Dads Help: Male Behavioral Care During Primate Infant Development

“…After the death of her mate, a captive owl monkey female had to bring up her infant with only the assistance of an older daughter (Jantschke et al 1998 ) . The older sibling provided substantial infant care, similar to the situation described for one wild group where the adult male died soon after the birth of the infant (Fernandez-Duque et al 2008 ) . In both cases, the carrying effort of the mother was essentially not higher than in groups with two adults, and in captivity the orphan infant was completely independent after 3 months, sooner than infants in groups with male caretakers (Jantschke et al 1998 , compare with Fig.…”

“…In our study population, males and females are replaced equally often. Between 2001 and 2010, we observed 25 female and 21 male replacements in a total of 142 group years in 18 groups (Fernandez-Duque et al 2008 ;Huck and Fernandez-Duque 2012 ) . Likewise, both sexes seem to have similar survival rates (survival analysis for 53 females and 52 males over 2 years of age, accounting for censored data and using a Weibull distribution, c ² = 0.06, p = 0.81).…”

“…The fi nal prediction about the females' ability to assess and compare males is more dif fi cult to test in a pair-living species, because there is no day-to-day choice between several males. Studies on mate selection previous to pair formation have not been conducted, but since males care for unrelated offspring when they enter new groups (Fernandez-Duque et al 2008 ) , infant care as a mating strategy cannot be refuted either. Thus, from the individual male's perspective, he might bene fi t in all three broad ways from providing paternal behavior.…”

Allogrooming in Male-Female Pairs of Captive Owl Monkeys (Aotus nancymaae)

“…Prior to mate replacement events, behaviors that indicate sexual interest, age and/or parental quality may be assessed by potential mates. In natural populations of owl monkeys, when established residents are evicted from their territories [Fernandez-Duque, 2004;Fernandez-Duque et al, 2008;Huck and FernandezDuque, 2013], they are often replaced by younger individuals . If these individuals signal interest via affiliative behaviors such as grooming or food sharing, they may be more likely to establish a pair bond with the resident.…”

Natal dispersal in monogamous owl monkeys (Aotus azarai) of the Argentinean Chaco

“…Most owl monkey species are strictly nocturnal, but the Azara's owl monkeys (A. azarai) of Argentina, Bolivia and Paraguay regularly show both diurnal and nocturnal activity (Wright, 1989;Fernandez-Duque, 2003;Fernandez-Duque & Erkert, 2006). The diurnal activity of this species has enabled researchers to examine the behavioural ecology of owl monkeys in some detail (FernandezDuque, 2003;Fernandez-Duque & Erkert, 2006;Fernandez-Duque et al, 2008;Wolovich et al, 2008).…”