Female copulatory vocalizations, also called female copulation calls or coital vocalizations are produced by female primates, non-primates, as well as human females. Copulatory vocalizations usually occur during sexual intercourse and are hence related to sexual activity.[1]
In non-human primates copulation calling is typically observed at the end of mating[2] and there are vast variations in between species regarding its occurrence, frequency and form. It is agreed that coital vocalizations fulfill an evolutionary purpose[3] and that they serve as adaptive solutions to problems that the females face, such as infanticide, as well as obtaining high quality sperm.[2]
In humans, coital vocalizations are linked to orgasm,[4] hence occurring during copulation and serving as an expression of sexual pleasure. Vocalizations can be used intentionally by women in order to boost the self-esteem of their partner and to cause quicker ejaculation.[5]
In non-human primates
editOccurrence, Frequency and Form
edit
In non-human primates, copulatory vocalizations begin towards the end of the copulatory act or even after copulation.[2] The percentage of vocalizations after copulation varies dependent on the non-human primate species studied. In long-tail macaques, for instance, 80% of copulations are followed by copulation calls. In contrast, the percentage for chimpanzees and Tonkean macaques has been found to be 78.8% and 6%, respectively.[7] There is little consensus on what causes these inter-specific differences, given the lack of consistent findings within the literature.[2] The typical quantity of specimen that are tested in experimental settings is often too low in order to allow any general conclusions about the species as a whole.[2]
Another aspect of coital vocalization that varies according to species is the form of the call: in macaques and baboons they manifest themselves as grunts, whereas other species such as talapoins and chimpanzees typically emit screaming sounds.[2] The quality and structure of copulatory calls are analyzed by comparing their respective spectrograms in terms of their frequency. Accordingly, some species produce calls that are structurally more complex than that of others. This is linked to the amount of promiscuity exhibited, in a way that more promiscuous species emit more faceted calls in order to convey more information about themselves and hence render self-advertisement more efficient.[6]
Adaptive Function
editCopulatory calls in primates serve an adaptive function and are sexually selected.[3] Calling signals receptivity of the female to mate and therefore affects mate choice. There are many different hypotheses as to the exact adaptive function of female copulatory calls in primates and research on the subject is still in its early stages.[2]
There is general agreement that copulatory calls are the adaptive solution to problems with reproductive success. In other words, copulatory vocalizations address issues that stand in the way of successfully producing offspring and guaranteeing its survival, such as the occurrence of infanticide [8]. In order to prevent the killing of their offspring, female baboons employ copulatory calls in order to attract other males, allowing multiple mating acts and creating parental confusion among the males involved. The resulting uncertainty of who the father is hence reduces the occurrence of attacks, given the newly incited risk of potentially harming their own offspring.[9] Additionally, mating in rapid successions also entails sperm competition, and therefore fulfills the additional function of obtaining high quality sperm.[10] This is especially important in species that do not openly advertise good genes via honest signals.[11]
By attracting other males through post-copulatory calls, the female might provoke mate guarding behavior in their initial mate. This 'parental concentration',[2] has two outcomes. Firstly, the male might be of high quality, allowing him to fend off those that were attracted by the call. In that case the female has not only gained someone who can protect her and who prevents infanticide through other males, but this also means that she was inseminated by a specimen with potentially good genes. Secondly, if the male fails to successfully guard her, she will mate with the newly arrived males, hence inciting sperm competition and paternity confusion (again preventing attacks on her offspring, as well as increasing her likelihood of obtaining high quality sperm). The calls produced by the female also carries information about the status of the male with whom she was copulating, thus allowing her to influence the likelihood of other males approaching.[4]
Accordingly, copulatory calls serve more than a single adaptive function. There is no mutual exclusivity when it comes to addressing the two problems described, namely that of infanticide and receiving high quality sperm. However, by taking the female's cycle stage into account, sperm competition can be ruled out as the primary underlying cause of copulatory calling. More precisely, females produce coital vocalizations also when they mate during non-fertile periods, which is therefore primarily aimed at attracting as many males as possible and to create parental confusion rather than obtaining high quality sperm[12]. Females have no interest in advertising their periods of fertility, given that males would pick up on these patterns, reducing paternal confusion and causing an increase in aggressive behavior towards her offspring from other males.[2]
In non-primates
editThis section gives an overview of copulatory calling in regard to animals that are not primates.
Occurrence
editIn addition to emitting copulatory vocalizations during and after copulation (as it is mostly seen in primates), non-primate species also vocalize before engaging in mating. Vocalizations that are made prior to copulation are named mating calls. They serve as a means to advertise sexual receptivity and are predominantly used by males to attract female mates.[13] In general, non-primates emit more calls before copulating, as exemplified by the croaks of male frogs[14] and the melodic tweeting of song sparrows. [15]
Properties
editIn regard to the calling properties, frequency analysis is typically used in research to look at the complexity of the vocalization and to distinguish between calls (which is important in determining their function).[16] Large frequency variations have been noted between species, ranging from 14 Hz to 70,000 Hz. Mice, for instance, use 70,000 Hz calls continuously prior to copulation. They then lower the frequency down to 40,000 Hz during the copulatory act, therefore two qualitatively different calls are used for attracting mates as compared to the actual act of mating[17] Most of the calling in mice is done by males. They use these ultrasonic calls (> 20,000 Hz and not discernible by the human ear) to attract females, with the quantity of calls being related to the male's mating success, making these vocalizations a sexually selected trait.[18]
On the other end of the spectrum, female African elephants, use very low frequency calls of 14–35 Hz prior to as well as during copulation.[19] Due to their low frequency these calls can be heard for several kilometers and are therefore effective in signalling receptivity. The vocalizations of female elephants are also used in order to incite mate guarding behavior in the male[20], which manifests itself in the form of fighting off any newly arriving mates. Not only females make use of this, as male Columbian ground squirrels have been observed to use copulatory vocalizations in order to announce their post-copulatory mate guarding to others.[21] In addition to being used to retain the mate via mate guarding induction, female copulatory vocalizations can also be employed to achieve his departure. Red junglefowls, for instance, utilize calls in order to prevent or end unwanted copulations by attracting another high-ranking male fowl.[22] Further effects of female calling on male's behavior are illustrated by spiders that have been shown to stridulate before copulation to inform males of sexual receptivity[23] as well as during intercourse in order to influence male genitalic movements.[24]
Moreover, attracting new mates by calling out during copulation can entail many benefits for the female. Female crickets which mate with multiple partners receive a greater number nuptial gifts[25], causing them to lay a larger quantity of eggs, hence increasing their reproductive success.
- ^ Thornhill, R.; Gangestad, S. W. (2008). The Evolutionary Biology of Human Female Sexuality. Oxford University Press.
- ^ a b c d e f g h i Pradhan, Gauri; Engelhardt, Antje; van Schaik, Carel; Maestripieri, Dario (January 2006). "The evolution of female copulation calls in primates: a review and a new model". Behavioral Ecology and Sociobiology. 59 (3): 333–343. doi:10.1007/s00265-005-0075-y.
- ^ a b Dixson, A. (2013). Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Humans. Oxford: UOP.
- ^ a b Christopher Ryan and Cacilda Jetha, ‘’Sex at Dawn: How We Mate, Why We Stray, and What It Means for Modern Relationships’’ (Harper Perennial, 2011), pp. 255-57.
- ^ Gayle Brewer and Colin A. Hendrie, “Evidence to Suggest that Copulatory Vocalizations in Women Are Not a Reflexive Consequence of Orgasm,” ‘’Archives of Sexual Behavior’’ 40:559-64 (June 2011)
- ^ a b J. Hamilton and P. C. Arrowood, “Copulatory Vocalizations of Chacma Baboons (Papio Ursinus), gibbons (Hylobates Hoolock) and Humans,” Science, 200:1405, 1406-07 (1978).
- ^ Maestripieri, Dario; Roney, James R. (2005-01-01). "Primate copulation calls and postcopulatory female choice". Behavioral Ecology. 16 (1): 106–113. doi:10.1093/beheco/arh120. ISSN 1045-2249.
- ^ Maestripieri, Dario. "Post-Copulatory Sexual Selection and Female Mating Vocalizations in Primates". Retrieved 24 March 2016.
- ^ O'Connell, Sanjida M.; Cowlishaw, Guy (1994-09-01). "Infanticide avoidance, sperm competition and mate choice: the function of copulation calls in female baboons". Animal Behaviour. 48 (3): 687–694. doi:10.1006/anbe.1994.1288.
- ^ Stockley, P (1997). "Sexual conflict resulting from adaptations to sperm competition". Trends Ecol. Evol. 12 (4): 154–159. doi:10.1016/S0169-5347(97)01000-8. PMID 21238013.
- ^ Maestripieri, Dario; Roney, James (2005). "Primate copulation calls and post-copulatory female choice". Behavioral Ecology. 16: 106–113. doi:10.1093/beheco/arh120.
- ^ Lukas, Dieter; Huchard, Elise (14/11/2014). "The evolution of infanticide by males in mammalian societies". Science. 346 (6211): 841-843.
{{cite journal}}: Check date values in:|date=(help) - ^ Fedorka, K.; Mousseau, T. (2001). "Material and genetic benefits of female multiple mating and polyandry". Animal Behaviour. 64 (3): 361-367.
- ^ Wilczynski, W., B. E. McClelland, and A. S. Rand. "Acoustic, auditory, and morphological divergence in three species of neotropical frog." Journal of Comparative Physiology A 172.4 (1993): 425-438.
- ^ Nemeth, E; Kempenaers, B; Matessi, G; Brumm, H (2012). "Rock sparrow song reflects male age and reproductive success". PLOS ONE. 7 (8): e43259. doi:10.1371/journal.pone.0043259. PMID 22927955.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Gerhardt, C. (1981). "Mating call recognition in the green treefrog (Hyla cinerea): importance of two frequency bands as a function of sound pressure level". Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology. 144(1): 9-16.
- ^ White, N. R., Prasad, M., Barfield, R. J., & Nyby, J. G. (1998). 40-and 70-kHz vocalizations of mice (Mus musculus) during copulation. Physiology & behavior, 63(4), 467-473.
- ^ Pomerantz, S. M., Nunez, A. A., & Bean, N. J. (1983). Female behavior is affected by male ultrasonic vocalizations in house mice. Physiology & behavior, 31(1), 91-96.
- ^ Poole, J. H., Payne, K., Langbauer Jr, W. R., & Moss, C. J. (1988). The social contexts of some very low frequency calls of African elephants. Behavioral Ecology and Sociobiology, 22(6), 385-392.
- ^ Poole, J. (1989). "Mate guarding, reproductive success and female choice in African elephants". Animal Behaviour. 37: 842-849.
- ^ Manno, T. G., Nesterova, A. P., Debarbieri, L. M., Kennedy, S. E., Wright, K. S., & Dobson, F. S. (2007). Why do male columbian ground squirrels give a mating call? Animal Behaviour, 74(5), 1319-1327.
- ^ Løvlie, H., Zidar, J., & Berneheim, C. (2014). A cry for help: Female distress calling during copulation is context dependent. Animal Behaviour, 92, 151-157.
- ^ Dutto, M. S., Calbacho‐Rosa, L., & Peretti, A. V. (2011). Signalling and sexual conflict: Female spiders use stridulation to inform males of sexual receptivity. Ethology, 117(11), 1040-1049.
- ^ Peretti, A., Eberhard, W. G., & Briceño, R. D. (2006). Copulatory dialogue: Female spiders sing during copulation to influence male genitalic movements. Animal Behaviour, 72(2), 413-421.
- ^ Tregenza, T.; Wedell, N. (1998). "Benefits of Multiple Mates in the Cricket Gryllus bimaculatus". Evolution. 52: 1726-1730.