What causes males to attack females after mating?


It is not uncommon for males to attack females after mating. This behavior, which is also known as post-copulatory sexual aggression, is prevalent in many species, including humans. It can be a source of pain and distress for the female, and it can also have serious implications for the health and survival of the offspring. In this article, we will explore the various factors that contribute to this behavior.

Sexual Conflict Theory

One of the main explanations for post-copulatory sexual aggression is sexual conflict theory. This theory posits that males and females have different reproductive interests, and that these interests may conflict with each other. Specifically, males are often more interested in mating with as many females as possible, while females are more interested in finding high-quality mates that will provide resources and protection for their offspring. This conflict can lead to aggression when males attempt to force females to mate with them, or when females resist mating.

Benefits and Costs of Mating

Mating can have both benefits and costs for males and females. For males, the benefits include the potential to father more offspring, while the costs include the risk of injury or death from competing males. For females, the benefits include the acquisition of resources and protection, while the costs include the risk of injury or death from aggressive males. These costs and benefits can create a situation where males may become aggressive towards females after mating, especially if they perceive that the female is not providing enough benefits.

Male Investment in Offspring

Another factor that can contribute to post-copulatory sexual aggression is male investment in offspring. In species where males invest heavily in offspring care, such as birds and mammals, males may become aggressive towards females in order to prevent them from mating with other males and diluting their genetic investment. This behavior is often seen in species where males provide extensive parental care, such as guarding the nest or feeding the young.

Female Resistance to Mating

Female resistance to mating can also be a factor in post-copulatory sexual aggression. In many species, females may resist mating with males that they perceive to be low-quality or that are not providing enough resources or protection. This can lead to aggression from the male, as he attempts to force the female to mate with him. In some cases, females may also use aggressive behavior to defend themselves against unwanted advances from males.

Hormonal Factors

Hormonal factors can also play a role in post-copulatory sexual aggression. In many species, males produce high levels of testosterone, which is associated with aggressive behavior. This can lead to increased aggression towards females after mating, especially if the male perceives that the female is not providing enough benefits. In addition, hormonal changes in females after mating, such as a decrease in estrogen levels, can also increase the risk of post-copulatory sexual aggression.

Genetic Factors

Genetic factors can also contribute to post-copulatory sexual aggression. In some species, males may have genes that promote aggressive behavior towards females after mating. These genes may have evolved as a way to increase the male’s reproductive success, but they can also have negative consequences for the female and her offspring. In addition, females may have genes that promote resistance to mating, which can also contribute to aggression from males.

External Factors

External factors can also play a role in post-copulatory sexual aggression. For example, environmental stressors such as food scarcity or predation risk can increase aggression in males. In addition, social factors such as competition for mates or social status can also lead to aggression towards females after mating.

Prevention and Management

Preventing and managing post-copulatory sexual aggression can be challenging, but there are some strategies that can be effective. One approach is to promote female resistance to mating, such as by providing females with resources and protection. Another approach is to reduce the risk of aggression from males, such as by separating males and females after mating or by providing them with adequate resources and space.


Post-copulatory sexual aggression is a complex behavior that is influenced by a variety of factors, including sexual conflict theory, benefits and costs of mating, male investment in offspring, female resistance to mating, hormonal factors, genetic factors, and external factors. Understanding these factors can help us to develop strategies for preventing and managing this behavior, and ultimately improve the health and wellbeing of females and their offspring.

Mary Allen

Written by Mary Allen

Hello, I'm Mary! I've cared for many pet species including dogs, cats, guinea pigs, fish, and bearded dragons. I also have ten pets of my own currently. I've written many topics in this space including how-tos, informational articles, care guides, breed guides, and more.

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