ANT211H5 Lecture Notes - Lecture 6: Castration, Parental Investment, Bluegill
Document Summary
Ant211: intrasexual competition: how males and females compete for mates. Advantage that certain individuals have over other individuals of the same sex. Outmaneuver or drive away other members of the same sex. Attract members of the opposite sex females: indirect competition with other females. Tends to be more confrontational & intense than females: because male reproduction is limited by action and competition of other males therefore more risk taking behaviour. Success of male reproductive effort: dependent on the reproductive effort of male competitors. Success of female reproductive effort: dependent on her own effort & less upon the effort expended by other females, commonly limited by their own physiology; parental effort more attributed to females. Cost of male reproductive effort: direct (e. g. deer) Males greater competitiveness, means greater risks (especially in young males) Selection for intense male mating effort leading to greater dissolution, death, disease. Castration: atrophy of male reproductive organs, reduced penile erection, reduced orgasm, decline in aggression.