Tsunamis, Speakers and Sabre-Tooth Tigers

Forest elephants living in West Africa's Congo Basin have learned to avoid roads probably because they realise that where there are roads there are poachers with guns.

That's according to a study published in the online journal Plos ONE, led by Stephen Blake from the Wildlife conservation Society. Blake and his team have shown that by avoiding roads elephants are confining themselves to smaller and smaller patches of habitat which could spell even more trouble for this endangered species.

The research team put collars on 28 elephants with Global positioning tracking systems and followed their movements through the forests of the Congo Basin. It became clear to them that elephants avoid roadways even in areas where poachers are kept out. During the whole study only a single elephant was recorded crossing a road and, when it did, it dashed across at 14 times its normal pace.

We might assume that if intelligent elephants have learned to avoid roads and poachers then this is a good thing because fewer of them will be shot.

But the problem is that the current book in road building is carving up the remaining areas of intact forest and the areas that elephants live in are contracting. It may be that elephant herds will not be able to find all the food and resources they need to survive.

There could even be a knock-on effect on the forest ecosystems since it is thought that when elephants roam large areas they play an important role in seed dispersal. This could be disrupted if they only live in small, separate patches of forest.

The good news is the research team have suggested that some relatively simple and cheap planning measures could be introduced that would make a real difference for the elephants. By planning exactly where roads go and trying to keep intact areas of forest that are as large as possible we should be able to minimise how much elephants continue to be confined by their fear of roads.

Take a step back to the time when sabre-toothed tigers roamed the land. A new study has suggested these toothy predators were not lone hunters but may in fact have lived in packs like many social carnivores do today.

That's according to Chris Carbone from the Zoological Society of London and his colleagues writing in the journal Biology Letters this week.

The unusual thing Carbone and his colleagues did was to study modern day carnivorous cats in Africa to help understand what their ancient ancestors were doing thousands of years ago.

Ancient tar pits in Los Angeles, the Rancho La Brea, contain the fossilised remains of over 2000 sabre-toothed tigers: the cats had come to the tar pits to feed on prey that had got caught in the sticky tar. The researchers wondered whether all these cats came individually or whether they came together in a pride.

As a way of investigating this, they played back the recorded sounds of prey animals in distress both in the Serengeti region of Tanzania and Kruger National Park in South Africa. There were the same sorts of sounds that the sabre-tooth tigers would have heard thousands of years ago, from wailing prey animals trapped and dying in the tar pits. What they found was that the number of large social carnivores turning up to the recordings was much greater than would be expected based on the overall population size. Around 84 % of the animals that came to check out the noise were lions and hyenas, both social animals.

And the sabre-tooth tigers appeared in a comparable proportion at the Los Angeles tar pits. Along with another animal called the dire wolf, they made up the same 84% as was seen in modern-day Africa; hinting that they too are social and roamed around in gangs - a much more efficient way of scavenging for food.

So as well as being a rather ingenious way of looking in to the past, this study hints at the importance of links between scavenging and living in social groups: something that early humans may well have done just like the sabre-tooths.