Ontogeny

Many environmental factors contribute to whether females choose to partake in cannibalism. Male availability versus alternative prey availability plays a large role in whether or not a female will eat a male. Availability of males obviously increases the rate of sexual cannibalism, but virgin females who do not have access to males for a period of time and therefore have yet to mate are significantly less likely to kill a male before mating with it regardless of the current number of males around.  Male-female sex ratios often change with season, implying that the seasons in which females are growing, and seasons in which females reach maturity and are ready to mate play a role in how likely they are to eat male partners as an alternative to mating. The health and potential genetic contribution of males in any given population also contributes to the likelihood of a female to partake in cannibalistic behavior.

Female aggression affects their chances of exhibiting precopulatory cannibalism potentially through genetic factors passed down through generations. Genetics aside, if an environment causes a female to adapt to limited food or other factors by increasing aggression at an early stage of life, studies show this aggression will likely be continued through maturation even if food becomes less scarce.


Female body condition also has the potential to affect chances of precopulatory cannibalism. One hypothesis proposes that it is an alternative reproductive tactic used by females. Below a certain weight, females are infertile and virgin females are unable to begin producing fertilizable eggs, so females may eat the males to gain weight and increase their fertility. In this type of system, there would be 2 different sexual phenotypes in females:

(1) pre-mating cannibalism by small females

(2) post-mating cannibalism by larger females with different encounter rates related to the males of different sizes and accordingly varying nutritional gains.