Newts do it. Whales do it. Even bloated hyenas (try to) do it. But not all species do it where we can see them. Snakes are rarely witnessed in the "throes of passion" and much of what we know about their mating behaviour comes from animals bred in captivity. While on a recent trip to South Africa's Kruger National Park, Kathy Gulyas Watson filmed a rarely seen encounter between two puff adders that appeared to be in the midst of courtship: 


Things kick off with a plump-looking puffy edging its way towards the roadside in lethargic fashion typical of the species. It's a female – her stumpy tail is the giveaway – and it's not long before she's joined by a frisky male. He quickly slithers aboard his potential mate – undeterred by the fact that he's facing the wrong way – and spends a minute resting on her back seemingly uncertain about how to proceed. Eventually she throws him off and disappears into the tall grass with her suitor in hot pursuit.

Videos of intertwined snakes usually trigger a healthy debate over whether or not the animals are mating or fighting, which is hardly surprising: courtship rituals often involve both battling and "dancing" and the behaviours can look quite similar. When a female puff adder is ready to mate, she releases pheromones that bring all the snake boys to the yard. These olfactory signals may even be sophisticated enough to relay information about a female's appearance, like how big or small she is.

It's not uncommon for more than one male to respond to the female's pheromones resulting in dominance battles which involve a fair share of twisting and turning as the males try their best to pin down the heads of their opponents. The stronger snake literally comes out on top as he's able to rear up higher than his rival in a show of strength that could land him some private time with a willing lady snake.

Mating does not look entirely different, although it's an altogether calmer affair and involves less vigorous gyrating and body raising. Males will climb on top of females and use their tails to twist and probe for the female's cloaca – a kind of general purpose opening through which snakes do pretty much everything except eat. Five or six months after impregnation, females give birth to 20-40 live young which are born in a membranous sack out of which they burst soon after birth.

For many snakes reproduction is a competitive affair. Some species, like garter snakes, form mating balls in which a writhing mass of mostly male snakes wrestle for prime position for a chance to transfer their biological material. Females are known to mate with multiple males and have the final say over whose young they chose to raise.

To gain a competitive edge, males may deposit more than just sperm. "Mating plugs" are made from a gelatinous substance used by male snakes to block a female's genital tract after copulation. Although there effectiveness is debatable, the plugs are just one element in a particularly peculiar stew of reproductive weirdness.

Snakes? Go figure ...


Header image: Die Thukrals/Flickr