The truth behind our “hiccupping” snake
Some visitors remember how Zoo Berlin’s baby orangutan Rieke had perpetual hiccups, and are worried that our Indian python is suffering the same fate. But we can put your minds at rest: this shaky snake doesn’t have the hiccups and isn’t ill – its behaviour is completely normal for the species.
A snake thermostat
The strange muscle contractions that so resemble hiccups are part of the Indian python’s normal breeding behaviour. Many python species exhibit these spasms. They enable the females to raise their body temperature above the ambient level – by as much as 5°C – so as to keep their eggs nice and warm. The pythons have no other way of doing this: as cold-blooded animals, snakes cannot simply warm their brood with their own body heat. The colder it is, the more the pythons shake. The ambient temperature in the terrarium at Aquarium Berlin is 29°C, but the perfect temperature for python eggs would be one or two degrees warmer.
Since the Indian pythons in the Aquarium have no predators to fear, no rivals for food, regular meals, and a pleasant ambient temperature, they produce young every year. Out in the wild where life is tougher and less predictable, pythons only reproduce every two years or so.
Since Aquarium Berlin has no current plans to breed Indian pythons, the eggs are taken away once they have been laid. But that doesn’t stop the snakes from shaking. Hormone levels and natural instincts cause the pythons to continue their convulsive behaviour even though the eggs are gone. This phase lasts 60 to 80 days – the length of the normal incubation period for Indian python eggs.
A time for fasting and for being slow
In general, snakes do not have regular meals. They are cold-blooded animals so don’t use up any calories on thermal regulation. During the breeding season, however, they take the starvation principle even further. Male Indian pythons eat nothing for two to three months, while the females go for up to four months without a meal – for the entire duration of the two-month gestation period and the two-month incubation period. However, the “hiccups” that occur during incubation use up a lot of energy. Therefore, the female keeps further energy consumption to the bare minimum during this time, barely shifting from the spot until her babies hatch.
Different strokes for different snakes
Using muscle contractions to raise body temperature is unique to the species of python that leave their offspring to fend for themselves once they’ve hatched. Different types of snake have very different approaches to parenting. Most boas give birth to live young, while adders defend their eggs from predators for several days before leaving them to their fate.
Changing the habit(at)?
Moving the snakes to another terrarium could put a stop to the Indian python’s peculiar behaviour, but the keepers choose not to resort to this measure. While the muscle contractions use up a lot of energy and may shock visitors a little, it is perfectly natural behaviour that does not impact on the snakes’ health. So we will allow our Indian pythons to keep “hiccupping” and simply accept that our staff will be approached by worried-looking visitors every now and again.