This month’s issue of National Geographic had a myth-busting revelation: that our beloved Rudolph the red-nosed reindeer must be female given that the caribou of North America and the reindeer of Eurasia are the only deer species in which both sexes grow antlers.
However, by November or December, antler equality undergoes a dramatic change. Once the cows are pregnant, adult bulls’ testosterone levels drop, their antlers fall off, and their behavior changes. No longer is there a need to aggressively drive off other bulls in rut to jealously defend their harems. Not so with the cows who keep their imperious racks until birthing time in April or May. Nonpregnant cows drop their racks a few weeks earlier.
You might wonder where I’m going with this. Campaign for changing the three him to her in the famous song lyrics? Create a new cause-celeb for why Rudolph should ‘go down in history’? Admonish Coach Comet for ostracizing Rudolph from the reindeer games? Or, for the staunch chauvinists, keep Rudolph male but dump the antlers? Well, what really struck me were some parallels between how sex hormones affect behavior and bone health in reindeer and humans.
Pregnant women often experience heightened libido via the action of increased sex hormone production resulting in larger and more sensitive breasts as well as an engorged and more sensitive vulva. Following giving birth, many women can experience a loss of desire or even an aversion to having sex that can last for months. A shift in sex hormone production is an accomplice culprit here. For the bulls, best beware lest they try to snuggle up to a pregnant cow endowed with a sturdy rack.
Sex hormone (testosterone) levels in adult bulls and men skyrocket during courtship rituals where facing competition elicits stinginess, dominant-aggressive, and antisocial behavior. But once fatherhood is realized, these take a precipitous fall and testosterone shows its more benevolent prosocial, protective, and generous sides. Family men also see testosterone take a back seat to oxytocin, the love hormone enabling social bonding/monogamy, trust, and generosity. This hormone helps fathers remain lovestruck with their partners and mothers bond with their infants.
Underscoring all these behavioral changes choreographed by sex hormones is how important these hormones are to our bones, and in the case of caribou and reindeer, their antlers. For me, Rudolph’s postpartum shedding of her rack serves as a compelling analogy for what happens to men and women when their sex hormone production goes awry such as in the case of menopause and osteoporosis. Skeletons become brittle as the amount of bone declines because removal of old bone exceeds formation of new bone.
Of course, where we humans have one up on the caribou and reindeer is our ability to freely engage in sex beyond its reproductive function and willingly benefit from its gratification and generative potentials. Keeping up production of sex hormones helps keep our bones stronger longer. Other hormones from the thyroid, the parathyroid, the pituitary, and the brain also control levels of calcium in the blood, energy levels, and ability to grow. Healthy bones need the correct levels of all of these hormones.
So let’s heed Rudolph’s example as a resolution for 2016: a robust sex life for a healthy rack!