Courtship and mating in free-living spotted hyenas

Female spotted hyenas (Crocuta crocuta) are larger and more aggressive than males, and their genitalia are heavily 'masculinized'. These odd traits in females pose unusual challenges for males during courtship and copulation. Here our goals were to describe and quantify the behavior patterns involved in courtship and copulation in Crocuta, and determine whether rates of affiliative behavior directed toward females by males vary with female age, social rank, or time to conception. We also inquired whether consort formation with a particular female was necessary for a male to sire that female's cubs. Behavioral observations and paternity data based on 12 microsatellite loci were collected over I I years from free-ranging hyenas in Kenya. Several of the courtship displays exhibited by male hyenas differed from those found in other carnivores, and appeared to reflect intense motivational conflict between tendencies to approach and flee from females. Most male advances were either ignored by females or elicited aggression from females toward males. Rates of male affiliative behavior toward females peaked around the time of conception. Although males behaved similarly toward young and old females in the highest social rank category, males directed more affiliative behavior toward older than younger females that were mid- and low-ranking. Multiple short mounts usually preceded a long mount, but intromission and ejaculation appeared to occur only during long mounts. Female receptivity was indicated by inhibited aggression toward the male and assumption of a distinctive receptive stance. The only behavior indicative of female proceptivity was following of the male by the female in mating contexts. Some males who sired cubs formed consortships with females whereas others did not, suggesting that individual male hyenas may adopt alternative reproductive tactics to attract and acquire mates. Our results also suggest that low fertility may be an important cost of female virilization in this species.