Competition and cooperation between litter-mates in the spotted hyaena, Crocuta crocuta

Results showed that dominance between litter-mates is established as early in development as the first day of life, such that offspring of low-ranking females fought more than of those high- ranking females.

Abstract

The development of intra-litter competition and cooperation is described in free-living and captive spotted hyaenas. Field data were collected on dominance relations in 26 twin litters, and additional behavioural analyses were performed on different subsets of this group. Intra-litter dominance relations were assessed on the basis of the direction of aggressive and appeasement behavior patterns. In all wild litters, one cub clearly dominated the other by the time cubs were observed above-ground, at 2–3 weeks of age. Within the 17 twin litters of mixed sex, female dominance over male litter-mates was significantly more common (N = 14) than the reverse (N = 3). When males were the dominant litter-mates, they were as aggressive towards their siblings as were females. Rates of intra-litter aggression were highest in the youngest age interval observed (1–2 months), and dropped significantly the next month. Peak monthly rates of intra-litter aggression correlated significantly with maternal rank, such that offspring of low-ranking females fought more than of those high-ranking females. High levels of intra-litter cooperation were observed in the context of coalition formation, and youngster affiliated more with litter-mates than with any other hyaena. In captivity, seven twin and two triplet litters were videotaped during the first 2 months of life, and were scored for aggressive interactions. Results showed that dominance between litter-mates is established as early in development as the first day of life.