Sea snakes attacking divers: a seduction error?

In the tropics, coral reefs are a favorite place for divers. The latter regularly report “attacks” by a venomous sea snake: Aipisurus levis. The reptile either moves quickly towards the divers, or tries to wrap itself around their limbs … and very rarely bite. Should we infer predatory behavior? Of course not! For example, there are very few accidents on the very popular beaches of Noumea in New Caledonia. However, the density of both reptiles and humans is significant and amounts to thousands of individuals. The explanation for this peaceful coexistence may lie in part in the different habitats and seasonality for the two species.

sea ​​snake season

Coastal bays.Anse Wata et des Citrons are some of the most beautiful beaches in the world. No wonder they have a large human population attracted by these little pieces of paradise. So why aren’t sea snake bites reported anymore? An intrigued group, including Australian evolutionary biologist and environmentalist Richard Schein, spent almost 17 years observing native snakes. Of the more than 4,000 specimens discovered, about 97% belonged to non-venomous species. Emidocephalus annulareor a turtle-headed snake. “This sea snake has become an expert at herding eggs on coral reefs. Useless, its poisonous apparatus regressed until it completely disappeared,” explains François Brichou, a researcher at the CNRS Center for Biological Research in Chiz. However, within 8 hours, the observer diver encountered at least one snake with venom glands, for example, Aipisurus levis or striped knitting is the emblem of New Caledonia.

Sea snakes are reluctant to bite unless disturbed by careless swimmers. Moreover, the latter are usually completed with a combination along with fins or diving shoes. Effective protection against reptile fangs in the unlikely event of a bite. But the real peace comes from the low spatial and temporal overlap between the two species. While tourists mainly enjoy the beach during the day, snakes prefer to hunt at night on the reefs where their prey hides. Seasonality remains a central pillar of this agreement. Indeed, the southern summer is synonymous with sunny holidays. However, “sea snakes enter their breeding season in winter,” says François Brichou. Time devoted to courtship and fights between males courting the same female. And beware of the careless swimmer inviting himself into the middle of the party!

Error in man

fish eater Aipisurus levis lives mainly in the tropical waters of Australia and New Guinea. “Attacks” on divers are usually listed here. But what is it really? Another group, with Richard Schein in their ranks, intended to observe the so-called “aggressor” in its natural environment, south of the Great Barrier Reef, for 27 months. Over more than 250 hours of diving, the researchers encountered a dozen sea snakes. A confrontation that allowed them to confirm their hypothesis: the “attacks” were in fact incorrect displays of courtship… An idea supported by previous research suggests that it is very difficult for reptiles to identify forms underwater. François Brichou is not surprised: “Such misunderstandings are common in the animal kingdom. For example, some toads mistake frogs for females of their own species.

In the southern winter, males Aipisurus levis join the reefs where the females live. Filled with testosterone, they look for the slightest bulky object – females are larger than them, capable of reaching 2 meters in length – in an attempt to mate. However, upon noticing the male, the female usually runs away. At least in order to test the physical capabilities of your potential partner. Thus, an attempt to escape by a diver – a large object – can be perceived by a snake as an invitation to chase it. “This is followed by wrapping around the penis, typical of sexual behavior,” describes François Brichou. To get to a potentially dangerous bite, the snake must perceive the diver as a danger.

Stand up for non-violence

How to avoid conflict with a sea snake? First, you need to know it well. Residents of New Caledonia are aware of the habits and habitats of local snakes, which are treated with respect. Tourists do the same! If, in spite of everything, a collision occurs, the diver has no reason to run. The best solution is to remain calm and still. And most importantly, do not try to take revenge! If she feels that she has been attacked, the snake defends itself and bites the hand that hit her. Thus, the majority of bites occur during fishing activities in Southeast Asia. The reptiles may not be the initial target, but sometimes they get caught in the net. “The animal is stressed, trapped, possibly even injured. Everything around him screams for him to defend himself,” depicts François Brichou. Hence the advice given to anglers to always wear gloves. The simplest thing is to leave the reptiles alone…

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