The Bruce Effect: An Evaluation of Male/Female Advantages

  title={The Bruce Effect: An Evaluation of Male/Female Advantages},
  author={Patricia L. Schwagmeyer},
  journal={The American Naturalist},
  pages={932 - 938}

Pregnancy Blocking in Rodents: Adaptive Advantages for Females

  • J. Labov
  • Biology
    The American Naturalist
  • 1981
Arguments are presented here that pregnancy blocking may have actually evolved as a female mechanism to minimize parental investment in offspring which are potentially susceptible to infanticide by the strange male.

How to escape male infanticide: mechanisms for avoiding or terminating pregnancy in mammals

The phenomenon whereby pregnancy may be inhibited or terminated when a female is exposed to non-sire males after mating is often, and rather generally, referred to as the ‘Bruce effect’. Widespread

Pregnancy Block from a Female Perspective

Consideration of potential female benefits and the implications of female advantage in pregnancy block suggest that this behaviour could evolve with little or no reference to male advantage, and may represent a potential reproductive cost to stud males.

Male-caused failure of female reproduction and its adaptive value in alpine marmots (Marmota marmota)

Reducing progesterone levels after the mating period and the lack of evidence for direct infanticide by new territorial males suggest a block of pregnancy as a likely explanation for reproductive failures in groups with male takeovers during gestation.

Exposure to strange adults does not cause pregnancy disruption or infanticide in the gray-tailed vole

It is concluded that neither the Bruce effect nor infanticide occurred differentially as a consequence of the treatments in gray-tailed voles, and field verification is recommended for other species of murid rodents that exhibit theBruce effect before the results are applied to evolutionary theory.

Pregnancy block in laboratory mice as a function of male social status.

  • U. Huck
  • Biology
    Journal of reproduction and fertility
  • 1982
The hypothesis that dominant male laboratory mice would be more effective in inducing pregnancy blockage than would subordinate males is tested and the possibility that pregnancy block would be less likely to occur in females impregnation by dominant males than in those impregnated by subordinates is tested.

Animal Behavioral Studies, Non-primates

  • H. Kokko
  • Biology, Psychology
    Encyclopedia of Violence, Peace, & Conflict
  • 2022

Intrasexual Selection: How Males Compete




Olfactory stimuli in mammalian reproduction.

In the article "Olfactory stimuli in mammalian reproduction," by A. S. Parkes and H. M. Bruce [ Science 134, 1049 (1961)], the acknowledgement (p. 1054, reference 31) should have read: "It is a

‘The Selfish Gene’

Factors in pregnancy blocking: age and reproductive background of females: numbers of strange males.

Pregnancy blocking experiments involving 731 female laboratory mice indicate an increased resistance among older females; an equal susceptibility among parous and non-parous females; and a lower pregnancy rate among females exposed to six males than those exposed to one or three males.

10 – Olfaction and Reproductive Behavior in Microtine Rodents

Levels of Aggression in Fluctuating Populations of the Prairie Vole, Microtus ochrogaster, in Eastern Kansas

Levels of aggression, as seen through wounding, were examined throughout a density cycle of the prairie vole, Microtus ochrogaster, in eastern Kansas to propose a model of population regulation based on the observed patterns of wounding.

Communal Litters of Peromyscus maniculatus

The finding of two females and eleven young occupying the same nest under natural conditions is recorded.

Social Behavior, Reproduction, and Population Changes in the House Mouse (Mus musculus L.)

The present study of the interrelations of social behavior, reproduction, and population changes in the house mouse (Mus musculus L.) was undertaken in an effort to understand some of the aspects of