Slither

Horny sea snakes are attacking divers because of this one trait

by Jennifer Walter
Updated: 
Originally Published: 
Jack Breedon

Oceana via Giphy

Sea snakes are a regular sight within the underwater ecosystems of the Indian and western Pacific oceans.

Claire Goiran

Most species are venomous but not aggressive.

The Olive sea snake, however, is known to go after humans, unprovoked.

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However, it hasn’t been clear why these snakes go out of their way to attack humans.

A report published August 19 in Scientific Reports finally gives us some answers.

Diver Tim Lynch, one of the study’s authors, collected data on his encounters with Olive sea snakes in the Great Barrier Reef between 1994 and 1995.

The analysis revealed 74 out of 158 of these encounters ended with the snake approaching the diver.

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Jack Breedon

All of these attacks happened between May and August — during mating season. Most of the snakes who approached divers were males, though sometimes female snakes did it too.

aaf.nyc via Giphy

The data suggests this was no coincidence. Run-ins with male snakes always happened:

1. After they interacted with a rival male, or...

2. They were unsuccessful in chasing after a potential female mate.

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For females, each encounter with a diver occurred after males lost sight of them in a mating chase.

Lynch and colleagues suggest the male sea snakes might mistake divers for potential mates or rivals.

Meanwhile, females might confuse them for hiding places to hunker down after being chased by males.

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It might sound odd that a snake could mistake a human diver for a mate or rival.

But research suggests sea snakes have poor vision and aren’t great at telling objects apart.

Claire Goiran

Jack Breedon

“In Sea Snake Vision, One Plus One Makes Three,” declares the title of a 2020 report in Current Biology. The report details the snakes’ bad job at distinguishing colors.

Jack Breedon

Luckily for divers, scientists say there’s a way to curb most snake attacks if they start getting aggressive:

Just stay still. The legless reptiles will realize that they’re confused, and eventually swim away.

Claire Goiran

Read more stories about animals here.

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