Sea snake attacks may be misdirected courtship
Attacks by venomous Olive sea snakes on scuba divers may be misdirected courtship behaviours, according to a new study.
James Cook University Professor Emeritus Ross Alford is one of the authors of a new paper published in the journal Scientific Reports. He said scuba divers frequently report unprovoked attacks by sea snakes, which can involve chasing and biting.
“The reasons for these attacks have been unclear. So, we analysed data collected between 1994 and 1995 describing Olive sea snake behaviour during encounters with one of the authors, Tim Lynch, when he was diving on the Great Barrier Reef,” said Dr Alford.
The researchers found that sea snakes approached the diver during 74 out of 158 encounters and this occurred more frequently during the mating season – between May and August.
“Males were more likely than females to approach the diver, especially during the mating season, and flicked their tongues near the diver’s body. Thirteen encounters involved sea snakes rapidly charging at the diver,” said Dr Alford.
The authors found that all charges occurred during mating season and those involving males occurred immediately after an unsuccessful chase of a female, or an interaction with a male rival.
“Three males were also observed coiling around the diver’s fin, a behaviour usually observed during courtship. Charges by females occurred after they were chased by males or lost sight of, and then re-approached, the diver,” said Dr Alford.
He said previous research has suggested sea snakes find it difficult to identify shapes in water.
The authors believe sea snake attacks may be caused by male sea snakes mistaking a diver for a rival snake or potential mate, and female sea snakes perceiving a diver as a potential hiding place.
“By staying still and allowing a sea snake to investigate them with its tongue, a diver is unlikely to escalate the encounter and be bitten,” said Dr Alford.