Factors Affecting Urine Washing Behavior in Tufted Capuchins (Cebus apella)

Abstract

Urine washing is a common behavior in strepsirrhine and platyrrhine primates, but its function is still poorly understood. We investigated the factors influencing urine washing behavior in 2 captive groups of tufted capuchins (Cebus apella). Urine washing was affected by group membership (subjects in the 2 groups urine washed at different rates) and was negatively related to age, but was not influenced by sex or dominance rank. Females urine washed less when in estrus, and the presence of an estrous female did not affect male urine washing behavior. We observed independent effects of diurnal and climatic variables on urine washing. Tufted capuchins urine washed more at midday and under conditions of higher temperatures and lower relative humidity. Both of the latter effects were evident only at the lowest temperatures (5-20°C). Our results indicate that urine washing is sensitive to multiple influences, and that hypothetical communicative or thermoregulatory functions do not fully account for its occurrence.

Female behavioral proceptivity functions as a probabilistic signal of fertility, not female quality, in a New World primate

“…Although scent marking in New World primates has been mainly investigated in relation to territoriality with little data available regarding its function of advertising female reproductive state (see Heymann, 2006), a study in cotton-top tamarins, a species that lacks behavioral indicators of the periovulatory period, provided evidence for a direct olfactory cue of ovulation that affects male sexual behavior (Ziegler et al, 1993a). Recent studies in both robust and gracile capuchins, however, have found no evidence in support of a potential function of scent marking within socio-reproductive contexts (Carnegie et al, 2005;Schino et al, 2011).…”

Social after-effects of fur rubbing in tufted capuchin monkeys (Cebus apella): increased antagonism and reduced affiliation

“…Urine washing in particular has been linked to social situations, especially in the context of submission (Miller et al, 2007), although other functions have also been proposed (e.g. Roeder and Anderson, 1991; Campos et al, 2007; Schino et al, 2011). Interference with subjects’ scent is consistent with the current results: group members reacted to potentially missing indicators of social status by displaying their own dominance status towards subjects and, not necessarily independently, refrained from reaffirming social bonds through affiliative displays.…”

Urine-washing in white-faced capuchins: a new look at an old puzzle

“…Numerous hypotheses have been offered to explain urine-washing by primates, including non-signalling functions such as thermoregulation (Schmidt & Seitz, 1967;Schwartz & Rosenblum, 1985;Roeder & Anderson, 1991;Heymann, 1995), moistening hands to improve grip (Castell & Maurus, 1967;Welker, 1973;Harcourt, 1981), stress-induced displacement behaviour (DuMond, 1968;Andrew & Klopman, 1974), and scent-trails for orientation (Eibl-Eibesfeldt, 1953;Milton, 1975); and signalling functions such as marking the home range (Charles-Dominique, 1977), asserting dominance (Perry, 1998;Campos et al, 2007), and communicating reproductive status (Hennessy et al, 1978;Milton, 1985;Boinski, 1992;Miller et al, 2008). None of these studies has examined the question using rigorous statistical methods that control for confounding variables (but see Schino et al, 2011).…”

“…have produced no conclusive answers regarding its function, though they agree that the behaviour is likely multifunctional and exhibits strong seasonal fluctuations (Robinson, 1979;Perry, 1998;Carnegie et al, 2005;Campos et al, 2007). Some research on captive C. apella suggests that urine-washing may be used for thermoregulation (Roeder & Anderson, 1991), but two recent studies oppose this claim (Miller et al, 2008;Schino et al, 2011). There is some qualitative evidence that urine-washing in C. apella is associated with receiving aggression and that alpha males urine-wash in response to sexual solicitations from females (Miller et al, 2008), but these findings could not be replicated in a subsequent study (Schino et al, 2011).…”

“…Some research on captive C. apella suggests that urine-washing may be used for thermoregulation (Roeder & Anderson, 1991), but two recent studies oppose this claim (Miller et al, 2008;Schino et al, 2011). There is some qualitative evidence that urine-washing in C. apella is associated with receiving aggression and that alpha males urine-wash in response to sexual solicitations from females (Miller et al, 2008), but these findings could not be replicated in a subsequent study (Schino et al, 2011). Miller et al (2008) also report an inverse relationship between urine-washing rates and serum cortisol, which suggests that urine-washing may be used to relieve stress.…”