Image courtesy of Jack Harvey Image courtesy of Erwin Voogt
Image
courtesy of Jack Harvey
Image
courtesy of Erwin Voogt
Another unusual characteristic about the spotted hyena is that unlike most carnivores, hyenas are born in an advanced stage of development. They are born with their eyes open, many of their teeth, and are suprisingly active (Applegate 1999). Litter size is one to two and they are born at any time of the year after a gestation of about 90 days (Mitchell 2002). Hours after birth, siblings of the same sex, usually female, begin battling for dominance. The one that wins keeps the other from nursing until it weakens and dies. The fighting occurs in the cubs' narrow tunnels so mothers are unable to intervene. This sibling rivalry kills about 25% of hyenas in their first month being the largest cause of baby hyenas' death (Postanowicz 2003).
Cubs are raised in communal dens, but are seldom or never provisioned or guarded by clan members. I read one study, conducted by Knight, Van Jaarsveld and Mills in 1992 where they found allo-suckling to occur. Three females with single cubs were denned together and cooperatively suckled the cubs. However, circumstances were rough: this occured at the culmination of one of the most severe droughts and cub mortality was significantly higher. Though this shouldn't be ignored, because of the plethora of data showing the opposite to be true, it is most likely that the circumstances are the explanation rather than kin selection of any sort.
Males play no parental role, and only a seldom few are even allowed anywhere near the dens where even offspring of high-ranking females will bully them (Estes 2004). Frank found that if any male were likely to be near the den, it would be the alpha male. The male would even occasionally lick the cubs (1986).
Usually female cubs stay with their mother in their natal clan. Males disperse at around two years; however, sons of the high-ranking females tend to emigrate later and are more likely to become dominant breeding males in the clans they join (Estes 2004). Frank's research found there to be at least two advantages to being the son of the alpha female in particular: 1. The ability to feed at will even amongst the highest ranking females and 2. The ability to remain in the natal clan significantly longer than the other natal males before emigrating (1986).
One other interesting fact that has been researched about the relationship between the mother and her cubs: spotted hyenas can apparently use acoustic signals for purposes of mother-infant recognition. The data Holekamp et al. collected in 1999 suggests that hyena whoops contain information about the age of the vocalizing individual. Mothers respond most vigorously to the higher-pitched whoops of their youngest cubs.
Image
courtesy of Erwin Voogt
This web site was created by Keeley Roles for an undergraduate class, Animal Behavior, at Davidson College Spring Semester 2004. Email keroles@davidson.edu with questions regarding this web page.
Home • Physical Characteristics • Female Dominance • Food, Predation, and Hunting • Social Spacing • Social Organization • Mating System • Offspring • References
