Which group below are all strategies male birds employ to avoid sperm competition?

Male adaptations to sperm competition include relatively large testes, large sperm stores and long spermatozoa, mate guarding and frequent pair copulations. Females show no obvious morphological adaptations to sperm competition but, by controlling whether copulations are successful, they probably determine its frequency and extent. Despite this, the evolutionary benefits females acquire from extra-pair fertilizations are poorly understood.