How females become hyenas
Few large mammals have such a bad record as the hyena: they like to feast on carrion, communicate with goosebump-inducing laughter and prefer to surround themselves with a somewhat idiosyncratic odor. As mothers, however, they give their offspring a valuable dowry: a dose of hormones for power.
One of the classics of zoological literature is of course the "animal life" by the unforgettable Alfred Edmund Brehm from Renthendorf near Neustadt an der Orla in Thuringia. However, less because of the scientific content of the work than because of the extremely flowery language in which the species descriptions are available. Although it is based on the state of zoology in the 19th century, it is by no means too bad for human judgements.
In this hodgepodge of noble and less noble representatives of the animal kingdom, the hyena should not be missing either. So what does Brehm write about them? An excerpt: "In addition, all hyenas are nocturnal animals, have a screeching or really horribly laughing voice, appear greedy, voracious, spread a foul smell and only have ignoble, almost limping movements: in short, it is impossible to call them beautiful."
And indeed, the carnivores living in Africa and - in the case of the striped hyena (Hyaena hyaena) - also in parts of Asia usually show a rather strange behavior: the spotted hyena (Crocuta crocuta) wallows gladly in rotting flesh, for the more they stink, the higher they rise in the ranks of their cronies. In the savannahs of East Africa they wage regular wars against lions, killing their offspring when the opportunity arises. And they may be contributing their bit to the extinction of the wild dogs, which they prefer to steal prey from and which are now particularly rare where hyenas thrive.
In addition - and this is unusual for pack-forming predators - the animals have reversed the distribution of roles: a female is - sorry - the master of the ring and leads the group. Alpha hyenas are larger, more aggressive, and more assertive when it comes to prey distribution than any male. Yes, they even have a kind of pseudo-penis that poses identification problems, at least from afar, even for experienced observers. The animals' clitoris is elongated and protrudes far from the inside of the body.
This anatomical peculiarity is possibly related to another peculiarity of the spotted hyena, which has now been uncovered by biologists led by Stephanie Dloniak from Michigan State University in East Lansing. They have been observing a stable matriarchy of the species in the Kenyan Maasai Mara Reserve for more than twenty years and have focused, among other things, on the reproductive success of the females and the development of the respective offspring.
With hyenas, it is not the case that only the alpha female gets involved with males, but other female parts of the pack, which can be up to sixty strong, are also allowed to do so. However, this means that the offspring of the leading female will have unfavorable competition in their own clan, which in turn cannot be in the interests of the mother. However, as Dloniak and her colleagues noted, the alpha female’s offspring behave in accordance with their status soon after birth: They are more aggressive, more robust and already show a significantly more sexualized behavior during childhood – in the form of playfully mounting fellows of the same age – than the boys of sub alterns. Their chances of surviving and even taking over the leadership of the pack are considerably higher than their competitors.
But where does this head start come from? Are they better taken care of than their comrades? Is it because of some kind of different upbringing? Do they suck up this status thinking with their mother's milk? The latter is pretty close to the truth, because according to the scientists' research, the alpha female gives her potential alpha offspring the appropriate dose of hormones for showing off and assertiveness in the womb.
In the fecal samples they analyzed, the heaps of alpha females in the last few weeks of pregnancy showed significantly increased levels of androgens - a mix of male sex hormones that controls muscle development and influences aggressiveness and sexual behavior. It is passed from mother to unborn child via the placenta, with male and female pups benefiting equally.
The alpha females can afford this allowance because, due to their strength, they are still very robust on the carcass even when pregnant and thus get hold of more nutritious meat than their competitors. The hormone-related future assertiveness and repressiveness of the young women is bought at a high price at the same time as the anatomical changes in the clitoris, because mating and childbirth are made significantly more difficult by their lengthening.
However, according to Dloniak's team, the increased hormone doses could not only be part of the problem, but also the solution. Since the male descendants of the pack leaders practice mating in early childhood, they are more likely to learn the subtleties of complicated copulation and are thus later more successful in fathering children. Penetration into the clitoris only succeeds if the male hits exactly the right angle when mounting.
So the supreme mother of the company, with her hormonal dowry, not only ensures that the female pecking order is maintained, but also that her sons can preferably pass on the line of domination? What would Alfred Edmund Brehm have said about this very special kind of emancipation?