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Johannesburg – Professor Graham Alexander’s fascination with snakes started 50 years ago when he was gifted a brown house snake.
Now, decades later, this fascination with snakes has led Alexander to publish a ground-breaking study that finds female southern African pythons to be the first ever egg-laying snakes to care for their babies.
Alexander - from the Alexander Herp Lab at the Wits University School of Animal, Plant and Environmental Sciences - said this study had given a "great insight" into the biology and breeding habits of these snakes.
He said the female pythons did not eat during the breeding cycle and lost as much as 40% of their body mass over that time.
Professor Graham Alexander holding a clutch of Southern African Python babies (Supplied).
"This is the first-ever report of maternal care of babies in an egg-laying snake," Alexander said.
"I was amazed by the complex reproductive biology of this iconic snake."
Alexander’s study came after seven years of intensive fieldwork at the Dinokeng Game Reserve, north of Pretoria, where he tracked 37 pythons, using radio transmitters.
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During the course of his fieldwork, eight of the radio-tracked pythons laid eggs in aardvark burrows, while Alexander was recording their breeding behaviour.
Alexander’s study showed that the southern African pythons showed behaviour, such as family living and parental care, which weren’t associated with snakes.
An adult Southern African python (Supplied).
The study, which was published in the Journal of Zoology (London), found that the female python’s protective behaviour towards her offspring came at a great cost to themselves.
"Efficient basking is probably crucial for incubation. Unlike some other python species, southern African pythons are unable to warm their eggs by elevating their metabolism. Instead, our pythons bask near to the burrow entrance until their body temperature is almost 40°C (within a few degrees of lethal temperatures), and they then coil around the eggs to warm them with their sun-derived body heat," he said.
Alexander said he discovered that when the southern African female pythons breed they changed colour to almost black during the cycle. He said the adaption, called facultative melanism, had never been reported in snakes before and could allow for faster rates of heating during the basking phase.
"All of this takes its toll on mother pythons: they take a long time to recover after breeding and so can only produce a clutch every second or third year, depending on how many meals they are able to catch in the months after leaving the nest. Some of them never recover."
"I’ve got a very good record. I was bitten once by a puff adder, but that was because I didn’t handle it correctly. If you get bitten by something that’s not venomous, you don’t count it as a bite. You just move on," he said.
