Hyenas are fierce carnivores. If the numbers are in their favor, they will steal a wildebeest kill right under the noses of a lion pride enjoying their victory feast.
Hyenas exhibit sexual dimorphism: an innate size difference between male and female. Whereas spotted hyena males are smaller than females, males in other hyena species are larger.
Hyenas are quite social, though with a strict clan hierarchy befitting their ferocity. Spotted hyena clan size varies but may number up to 80.
Even the lowest-ranking spotted hyena females rank above the alpha males. Spotted hyena females not only keep males in their place, they compete intensely among themselves for status. With social dominance comes feeding and breeding privileges that confer dramatic gains in reproductive success.
Alpha females always hunt within clan territory. If the pickings are slim, subordinate females may have to travel outside home hunting grounds for a meal; a risky endeavor.
The offspring of top females grow faster and are more likely to survive than subordinate hyenas. This puts them on track for dominance in the next generation.
Penises are quite something as a social signal. Spotted hyenas prefer sniffing a penis, even taking a lick upon occasion, to the more mundane whiffing of anal glands common among other mammal species, such as dogs and cats, to which the hyena is a distant relation.
Spotted hyena attention to penises applies to both genders. Spotted hyena females have pseudo-penises, which are much like male penises in look and behavior. An erect pseudo-penis is used between females to say hello, as it is with males.
The female pseudo-penis is fully functional: used for urination and copulation. The female pseudo-penis precludes the possibility of rape, as well as making mating more laborious for males.
Some other species, including the squirrel monkey, lemur, and bearcat, have pseudo-penises. Elongated labia occasionally appear in humans.
The biological cost of the pseudo-penis is considerable. The birth canal extends through the pseudo-penis, constricting the canal such that birth delivery (parturition), particularly of first-borns, often leads to fatal complications for both mother and pup. After parturition, the pseudo-penis is stretched out of shape, alleviating much of the danger of the next pup birth.
The microbiotic bacteria that live in hyenas make a pungent paste – hyena butter – in pouches situated next to a hyena’s anus. Butter quality is variable; an ideal honest signal.
Hyenas dab spots of the smelly paste on grass, giving conspecifics a wealth of information. Besides telling the time of the visit, hyena butter gives a medical status report, including sexual receptivity. As part of the butter, the microbes that once lived in hyenas are now on diplomatic duty, talking on behalf of their erstwhile host.
Scent posts are bulletin boards, pastes are business cards, and bacteria are the ink, shaped into letters and words that provide information about the paster to the boards’ visitors. Without the ink, there is potentially just a board of blank, uninformative cards. ~ Kevin Theis