A case of adoption in a wild group of black-fronted titi monkeys (Callicebus nigrifrons)

Abstract

We observed a case of infant adoption in an unprovisioned group of wild black-fronted titi monkeys (Callicebus nigrifrons). During our long-term field study we noticed that an infant had moved from one of our study groups ("Desbotado") to another ("Rio"). Observations of the adoptive group confirm that it was being cared for by the adult male, and initially the group's adult female was nursing the infant alongside her biological infant. Interestingly, the native and adoptive groups have frequent inter-group interactions, but at no point have we observed the native group trying to retrieve its infant. As of April 2007 the infant has been living in its adoptive group for 19 months. These data document the first case of adoption in this genus; they suggest that infant recognition is poorly developed in this species and that under certain circumstances wild groups of C. nigrifrons can successfully rear twins. In our study population reproductive females give birth to one infant every year; the only case when this has not happened is with the group that adopted the infant, suggesting that adoption may generate a reproductive cost.

The alarm call system of wild black-fronted titi monkeys, Callicebus nigrifrons

“…Many birds and mammals produce specific vocalisations to predators, a behaviour that can function to alert conspecifics and to communicate detection to the predator (Caro 2005). Some species produce several acoustically distinct alarm calls in response to different predator types (Seyfarth et al 1980a, b;Manser et al 2002;Templeton et al 2005), but in others, the nature of the danger encountered is reflected by the number of calls per sequence (Schel et al 2009), the rate of call delivery (Lemasson et al 2010), the intensity of calls (Blumstein 1999), or by combinations of calls (Arnold and Zuberbühler 2006a, b).…”

“…Indeed, in some species, listeners respond in part by looking towards the caller, thereby demonstrating that calls are easily localisable. In some cases, there is direct evidence that these calls are also directed at the predator (Zuberbühler et al 1997;Caro 2005). Communicating to a predator can be adaptive if the signal indicates detection and so interferes with an ambush and surprisebased hunting strategy (Zuberbühler et al 1997(Zuberbühler et al , 1999Clarke et al 2006).…”

Fostering of a wild, injured, juvenile by a neighbouring group: implications for rehabilitation and release of Barbary macaques confiscated from illegal trade

“…Although adaptive explanations for adoption have been proposed (e.g. adopting orphaned relatives or learning parenting skills, see Thierry and Anderson 1986), it is often maladaptive: adopting can increase females’ interbirth interval (Agoramoorthy and Rudran 1992; Cäsar and Young 2008) and compete with biological offspring (Dunham and Opere 2016) and in Barbary macaques, “kidnapping” by relatives can kill infants by starvation and dehydration (Kuester and Paul 1986). It therefore seems most likely that adoptions, group fostering, and kidnapping are non-adaptive by-products of alloparental care (Hrdy 1976; Thierry and Anderson 1986), which may be under strong positive selection (reviewed by Hrdy 1976; Dunayer and Berman 2018).…”

Twinning in titis (<i>Callicebus coimbrai</i>): stretching the limits of biparental infant caregiving?

“…In captivity, the two twin births observed in C. moloch each resulted in the loss of one of the infants shortly after birth (Valeggia et al, 1999). There is, however, one unusual case of an adoption in a Callicebus nigritus group (Cäsar and Young, 2008), where the breeding pair cared for, and raised two infants simultaneously, although rearing success may have been mediated by factors such as the different ages of the infants and the fact that only one of them was reared throughout the whole weaning period. A remarkably similar pattern has been recorded in Azara's owl monkey (Aotus azarae), a species similar to titis in body size (adult weight ca.…”