Table 1.

Mechanisms of Competition Over Mates and Gametes, Based on and Developed from Table 1.1.1 in Andersson (1994)

Mechanisms	Favoured traits in competing sex
Scramble competition	sensory and locomotory organs to quickly locate mates (for example hearing, olfaction)
Endurance rivalry	ability to endure prolonged reproductive activity (for example condition, lifespan)
Contest competition	ability to outcompete rivals before mating through direct combat (for example body size, weapons), or ability to avoid such competition through alternative reproductive tactics
Mate choice	competition to be chosen through behavioral or morphological traits that the opposite sex finds attractive (for example ornaments, indicators of ‘good’ or compatible genes), or resources that the other sex needs (for example territory, nuptial gift, parental care), or ability to circumvent mate choice (for example forced copulations)
Gamete competition after mating	ability to outcompete rivals through gamete competition after mating (for example large numbers of sperm, large size of eggs), or ability to avoid that gamete competition (for example mate guarding, mating plugs)
Cryptic mate choice	competition to be chosen after mating through traits that the opposite sex prefers (for example ‘good’ or compatible genes)