Our species has driven countless animals extinct. But it turns out we aren’t the only humans to cause environmental chaos. New research has found our Neanderthal cousins likely wiped out a whole Portuguese tortoise species1.
Tortoise of Portugal
The victim of the Neanderthals was Hermann’s tortoise. Whilst once it roamed Portugal, it disappeared from the area around 70,000 years ago, vanishing from the record of Gruta da Figueira Brava and Gruta da Oliveira. These are two key Portuguese sites from this period1.
Although there are a few later instances of the species in the fossil record, they’re fragmentary and it can’t be confirmed if they actually belong to this species. Which means that even if they didn’t go extinct 70,000 years ago; they must have had least dropped in number so much we can’t reliably tell if they’re still around1.
So what happened then? Well, 70,000 years ago marks the start of Marine Isotope Stage 4. This was a period of moderate glaciation in Europe. However, that was actually a warmer climate than prior periods which featured much more extensive glaciation. As such, it’s unlikely that drove these tortoises extinct1.
Instead, we have to turn to the other inhabitants of Gruta da Figueira Brava and Gruta da Oliveira. See, the turtle fossils weren’t just there by chance. These were Neanderthal sites, whose owners regularly hunted. chopped up, and ate these turtles1.
Now, these turtles are fairly small and so didn’t make up a massive part of the Neanderthal diet. They appear to have been opportunistically grabbed to supplement their regular diet, which featured exciting things like elephants and bison1.
So if Neanderthals weren’t intensively hunting them, can they really be blamed for these tortoise’s extinction?
Well, despite the fact Neanderthals weren’t going out of their way to get these tortoises, they still had a big impact on the species. These reptiles are slow to grow and reproduce, so even this opportunistic hunting caused trouble for them.
We can track that because these tortoises were shrinking. Literally. As Neanderthals had there way with them the actual animals became smaller and smaller1.
This shows that these animals were living shorter lives, failing to reach the sizes of their ancestors. And shorter lives means they had fewer chances to reproduce before the Neanderthals ate them1.
And before long these tortoises weren’t just small. They were gone. But they still had the last laugh, surviving on in other parts of Europe. Meanwhile, the Neanderthals went extinct for realsies.
- Nabais, M. and Zilhão, J., 2019. The consumption of tortoise among Last Interglacial Iberian Neanderthals. Quaternary Science Reviews.