[ **up: [[Sexual cycle]]** ] --- # Oestrous [[2025-0313. Oestrus is the 'hormonally controlled, regularly repeated stages by which the body is prepared for reproduction' in most female mammals.|Oestrus is the 'hormonally controlled, regularly repeated stages by which the body is prepared for reproduction' in most female mammals.]][^1] [[2025-0314. 'Because in many primates, despite the intensification of copulation in the ovulatory phase of the cycle, females also allow males to copulate in other phases ... among others, have maintained that oestrus does not occur in this order.'|’Oestrus is a period of strong sexual drive in the female cycle in which the female accepts male copulation. It is very clearly marked in, for example, rodents, carnivores, and lemuroids.’]][^2] [[2025-0314. 'Because in many primates, despite the intensification of copulation in the ovulatory phase of the cycle, females also allow males to copulate in other phases ... among others, have maintained that oestrus does not occur in this order.'|’Because in many primates, despite the intensification of copulation in the ovulatory phase of the cycle, females also allow males to copulate in other phases, Chalmers (1979), Loy (1987, cited by Wallis and Englander-Golden 1992), and Martin (1990, 1992), among others, have maintained that oestrus does not occur in this order.’]][^3] --- ## Etymology > It is scarcely necessary to point out that the nominative form is oestrus, and the adjectival form oestrous (cf. fungus, fungous; mucus, mucous).[^4] > The very word oestrus derives from the Greek for gadfly; the implication being that the female is goaded into a state of sexual heat at the approach of ovulation.[^5] --- ## Stages of Oestrus [[2025-0313. The oestrus cycle has four phases - (1) pro-oestrus, (2) oestrus, (3) metoestrus, and (4) dioestrus.|The oestrus cycle has four phases - (1) pro-oestrus, (2) oestrus, (3) metoestrus, and (4) dioestrus.]][^6] > (1) **pro-oestrus (follicular phase)** – Graafian follicles develop in the ovary and secrete oestrogens; > > (2) **oestrus (heat)** – ovulation normally occurs, the female is ready to mate and becomes sexually attractive to the male; > > (3) **metoestrus (luteal phase)** – corpus luteum develops from ruptured follicle; di > > (4) **dioestrus** – progesterone secreted by corpus luteum prepares uterus for implantation.[^7] --- ### Pro-oestrus ### Oestrus ### Metoestrous ### Dioestrus [[2025-0314. Dioestrus is 'a period of sexual inactivity between periods of oestrus in animals that have several oestrous cycles in one breeding season'.|Dioestrus is 'a period of sexual inactivity between periods of oestrus in animals that have several oestrous cycles in one breeding season'.]][^8] --- ## Cycle length/frequency ### Monoestrous [[2025-0313. The oestrus cycle has four phases - (1) pro-oestrus, (2) oestrus, (3) metoestrus, and (4) dioestrus.|’The length of the cycle depends on the species: larger mammals typically have a single annual cycle with a well-defined breeding season (they are described as monoestrous). The males have a similar cycle of sexual activity.’]][^9] ### Polyoestrous [[2025-0313. The oestrus cycle has four phases - (1) pro-oestrus, (2) oestrus, (3) metoestrus, and (4) dioestrus.|’Other species may have many cycles per year (i.e. they are polyoestrous) and the male may be sexually active all the time.’]][^10] - [[Polyoestrous]] --- ## Alternatives to oestrus terminology [[2025-0321. 'Alternatives to the use of oestrus terminology have been available for over 20 years and are equally applicable to all female mammals. Beach (1976) proposed a schema which divides female sexuality into three components.'|'Alternatives to the use of oestrus terminology have been available for over 20 years and are equally applicable to all female mammals. Beach (1976) proposed a schema which divides female sexuality into three components: attractivity (i.e. sexual attractiveness), proceptivity, and receptivity.']][^11] - **sexual attractiveness:** non-behavioural cues such as genital appearance or odours.[^12] - **proceptivity:** female behavioural patterns displayed to initiated/maintain sexual interactions.[^13] - **receptivity:** female willingness to accept the male and permit copulation.[^14] --- ## Examples - [[House mouse#Reproduction#Oestrus|Oestrus in house mice (Mus musculus)]] [^1]: Michael Allaby (ed.), *A Dictionary of Zoology*, 5th edn. (Oxford University Press, 2020), s.v. ‘oestrus cycle (estrus cycle)’. [^2]: Bogusław Pawłowski, ‘[[Pawłowski. ‘Loss of Oestrus and Concealed Ovulation in Human Evolution_ The Case against the Sexual-Selection Hypothesis’, 1999.|Loss of Oestrus and Concealed Ovulation in Human Evolution: The Case against the Sexual-Selection Hypothesis]]’, *Current Anthropology,* vol. 40, no. 3 (June 1999), pp. 257–295. [^3]: Bogusław Pawłowski, ‘[[Pawłowski. ‘Loss of Oestrus and Concealed Ovulation in Human Evolution_ The Case against the Sexual-Selection Hypothesis’, 1999.|Loss of Oestrus and Concealed Ovulation in Human Evolution: The Case against the Sexual-Selection Hypothesis]]’, *Current Anthropology,* vol. 40, no. 3 (June 1999), pp. 257–295. [^4]: M.A. Hill, ‘Estrous Cycle’, *Embryology*, retrieved 24 December 2024, https://embryology.med.unsw.edu.au/embryology/index.php/Estrous_Cycle. [^5]: Alan F. Dixson, *[[Dixon. 'Primate Sexuality', 1998.|Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Human Beings]]* (Oxford: Oxford University Press, 1998), p. 93. [^6]: Elizabeth Martin and Robert Hine, *A Dictionary of Biology*, 6th edn. (Oxford University Press, 2008), s.v. ‘oestrus cycle (sexual cycle)’. [^7]: Elizabeth Martin and Robert Hine, *A Dictionary of Biology*, 6th edn. (Oxford University Press, 2008), s.v. ‘oestrus cycle (sexual cycle)’. [^8]: Collins English Dictionary* (2012 Digital Edition), retrieved 14 March 2025, https://www.dictionary.com/browse/dioestrus, s.v. ‘dioestrus’. [^9]: Elizabeth Martin and Robert Hine, *A Dictionary of Biology*, 6th edn. (Oxford University Press, 2008), s.v. ‘oestrus cycle (sexual cycle)’. [^10]: Elizabeth Martin and Robert Hine, *A Dictionary of Biology*, 6th edn. (Oxford University Press, 2008), s.v. ‘oestrus cycle (sexual cycle)’. [^11]: Alan F. Dixson, *[[Dixon. 'Primate Sexuality', 1998.|Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Human Beings]]* (Oxford: Oxford University Press, 1998), p. 94. [^12]: Alan F. Dixson, *[[Dixon. 'Primate Sexuality', 1998.|Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Human Beings]]* (Oxford: Oxford University Press, 1998), p. 94. [^13]: Alan F. Dixson, *[[Dixon. 'Primate Sexuality', 1998.|Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Human Beings]]* (Oxford: Oxford University Press, 1998), p. 94. [^14]: Alan F. Dixson, *[[Dixon. 'Primate Sexuality', 1998.|Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Human Beings]]* (Oxford: Oxford University Press, 1998), p. 94.