Behavioral indicators of ovarian phase in white‐faced capuchins (Cebus capucinus)

Abstract

In many primate species, conspicuous behavioral and/or morphological changes are indicators of the fertile phase of the female cycle. However, several primate species, such as the white-faced capuchin, lack these cues. This is referred to as "concealed ovulation," and is argued to be a reproductive strategy that confuses paternity and lowers the risk of infanticide. We studied 10 adult female white-faced capuchins in Santa Rosa National Park, Costa Rica, from January to June 2002. We determined their ovarian cycling patterns by analyzing fecal ovarian hormones, and compared simultaneously collected behavioral data to determine which, if any, cues females use to signal their fertile phases. We found that four females cycled during the study period but ceased to cycle without becoming pregnant. We considered several explanations for the lack of conception during our study, including reproductive seasonality. We found that female C. capucinus showed only small increases in rates of affiliative/proceptive behaviors directed toward adult males during their periovulatory phases. The best indicator of cycle phase was a significant increase in male affiliative behaviors (e.g., following and grooming bouts) and sexual behaviors (e.g., copulations and courtship displays) directed toward females during the periovulatory phase compared to the nonovulatory phase. Our finding that females exhibit little proceptive behavior, but that copulations and male courtship are nonetheless concentrated in periovulatory phases suggests that even though females do not provide behavioral and morphological cues to ovulation, males are still able to detect it. Infanticide occurs with some frequency in these monkeys, and there is evidence for postconceptive mating as a female strategy to lower risk of infanticide via paternity confusion. However, despite this occurrence of nonconceptive mating and the absence of female cues to ovulation, truly concealed ovulation does not appear to be characteristic of this study population of white-faced capuchins.

Relationship between sexual interactions and the timing of the fertile phase in captive female Japanese macaques (Macaca fuscata)

“…Our finding that the frequency of proceptive behaviors was not higher during the periovulatory period is in agreement with some studies [Brauch et al, 2007;Carnegie et al, 2005;Heistermann et al, 2001;Higham et al, 2009] but contrasts with many studies in humans and nonhuman primates [Bullivant et al, 2004;Carosi and Visalberghi, 2002;Engelhardt et al, 2005], including the Japanese macaque [O'Neill et al, 2004]. It seems unlikely that endocrine deficiencies accounted for the differences between O'Neill's study and ours since we reported a normal temporal pattern for estrogen and progesterone profiles.…”

Effects of Reproductive Status on Energy Intake, Ingestion Rates, and Dietary Composition of Female Cebus capucinus at Santa Rosa, Costa Rica

“…Though authors of preliminary research have shown that capuchin females occasionally may be nonpregnant and nonlactating, yet not cycling (Carnegie et al 2005), we do not have sufficient hormonal data to determine how often and for how long this occurs. Therefore, we combined all nonpregnant/nonlactating females into the cycling female category, which comprised 5 individuals.…”

Why do captive tufted capuchins (Cebus apella) urine wash?

“…Boinski [1992] commented that communication of reproductive status may be a primary function of UW in Saimiri oerstedii because both sexes increased UW frequencies as the mating season approached. Conversely, Carnegie et al [2005] found that female C. capucinus urine washed more often during nonovulatory phases vs. ovulatory phases. Carnegie et al [2005] concluded that UW could have functions other than communicating reproductive state or that periovulatory females may reduce their UW rates to lower the potential for communicating their fertile status to males through urine.…”

“…Conversely, Carnegie et al [2005] found that female C. capucinus urine washed more often during nonovulatory phases vs. ovulatory phases. Carnegie et al [2005] concluded that UW could have functions other than communicating reproductive state or that periovulatory females may reduce their UW rates to lower the potential for communicating their fertile status to males through urine. There is little information available on capuchins that directly examines UW relative to communication during sexual encounters.…”

“…Various hypotheses have been proposed for the functionality of UW in capuchins, most commonly thermoregulation, scent marking, communication during aggression, communication of ovulatory phase, cleansing of the hands and olfactory recognition of conspecifics [Carnegie et al, 2005;Roeder & Anderson, 1991;Ueno, 1991Ueno, , 1994a. Additional studies of UW in wild and captive capuchins may be necessary to determine the function(s) of UW in Cebus spp.…”