Flipping Tortoises

Credit: RubberBall / Alamy. Via BBC

A couple of our contributors have connections to tortoises through the Galápagos Islands, or at least from reading about them in the news. We’d always been aware of the danger for tortoises if they were flipped on their backs, but had never given the issue much evolutionary thought to consider the variations in the animals’ shells. Now, scientists at the University of Belgrade have published a paper on the self-righting ability of Hermann’s tortoises, which live in the Mediterranean. Matt Walker writes for the BBC:

Depending on your point of view, it is one of life’s great questions.

How does a tortoise that has flipped onto its back, get up again?

It’s not a rhetorical question, and it goes beyond being a metaphorical or metaphysical query, or a subject for drunken debate.

For a tortoise it is a deadly serious matter; being able to right itself counts as one of life’s epic struggles, a potential matter of life and death.

Dr Ana Golubović at the University of Belgrade, Serbia and colleagues studied the slow-motion thrashings of an inverted chelonian – in particular the Hermann’s tortoise, to see how the shape of its shell impacts its ability to rise again.

Armoured animals can easily lose their balance and fall on their back, where they are vulnerable to exposure, starvation and predation.

Tortoises are particularly susceptible, being unable to flip themselves by twisting their bodies inside their shells.

While researchers have long thought that the height and length of a tortoise’s shell may impact righting ability, no one had tested the effect of shell geometry on live animals.

Hermann’s tortoises are medium-sized tortoises that live in the Mediterranean. Female are generally larger than males.

Dr Golubović and her colleagues analysed 118 Hermann’s tortoises (54 females and 64 males), placing each on its back and then measuring how much time they spent furiously waving their heads, legs and tail in a bid to recover. They then compared this performance with the geometry of the tortoise’s shell.

You can read the rest of Walker’s original article here.

One thought on “Flipping Tortoises

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s