‘Polka-dot’ termite mounds support thriving ecosystems

The regular polka-dot pattern of termite mounds on the savannah of central Kenya supports a great abundance of plant and animal life – more than the region could support without the termites. The discovery, made by American and Belgian scientists, suggests regular patterns like this are so beneficial we should expect to see them in many other ecosystems.

The red dots are termite mounds. Image: Robert M. Pringle/Plos Biology

While studying geckos on the African savannah, the scientists noticed that the lizards tended to congregate around the sprawling termite mounds. Looking more closely, they discovered that it wasn’t just lizards that preferred the mounds – they were covered in a dense layer of plants and animals. The numbers of plants and animals decreased as the scientists moved further away from the mound, suggesting the mounds were responsible for supporting a thriving local ecosystem, but how do they do so?

The scientists aren’t sure. They think the termites, which create elaborate nests up to ten metres across, alter the soil structure by mixing in larger particles of soil. This helps water filter down to plant roots. The termites also seem to stir into the soil more nutrients such as phosphates and nitrogen, which plants need to grow. Increasing the number of plants boosts herbivore and insect numbers, which draws in predators like the geckos.

It doesn’t stop there. The regular spacing of the termite mounds across vast swathes of savannah support a much more productive ecosystem on a much larger scale. The regular spacing means no area is very far from a mound and its life-supporting effects, so the entire ecosystem can be more productive.

The findings should also be useful in completely different environments: conservation work to restore coral reefs or forests can use the idea of regular ‘polka-dot’ spacing to ensure that the fragile ecosystems are as strong as possible while they recover.

Paper Reference: Pringle RM,  Doak DF,  Brody AK,  Jocqué R,  Palmer TM, (2010) Spatial Pattern Enhances Ecosystem Functioning in an African Savanna. PLoS Biology, 8(5). e1000377. doi:10.1371/journal.pbio.100037

Spitting Cobra anticipates your every move

The spitting cobra – feared for its ability to blind by spraying venom into the eyes of its victims – anticipates the movements of its target, ensuring its venomous spray hits the mark every time.

It's watching you... A red spitting cobra. Image: Pogrebnoj-Alexandroff/Wikimedia

There are several species of spitting cobra, all of which live in Africa. None of them can control the direction of the stream of venom they can fire from tiny forward-facing holes in their fangs. Instead, the snakes must move their entire head to track the target. At the moment of attack, however, the snake stops tracking and instead anticipates where the targets’ eyes will be 200 milliseconds later – the length of time it takes the snake to launch the venom.

A team of German and American scientists spent six weeks goading a spitting cobra to fire streams of venom at a researcher wearing a protective mask while they filmed the snake using a high speed camera to capture 500 frames per second. They found that a sudden movement from the target triggers the spitting attack. At this point the snake can be reasonably sure where the target will be by the time the snake can release its venom, ensuring the venom lands with pinpoint accuracy.

The spitting cobra’s predictive skills are surprising as the precise planning required to do so was thought to be beyond its relatively simple reptilian brain.

So how can you ensure the snake doesn’t spray venom into your eyes should you ever encounter one? Simply don’t poke it with a stick, or disturb it in any way. Spitting cobras don’t use their venom spray aggressively; it’s purely a defensive strategy used to deter predators and other irritating large animals…

Paper Reference: Westhoff, G., Boetig, M., Bleckmann, H. and Young, B. A. (2010). Target tracking during venom ‘spitting’ by cobras. Journal of Experimental Biologists. 213, pp 1797-1802. doi: 10.1242/jeb.037135

Quantum botany?

Plants – the fairly ordinary green things that we see around us every day – have harnessed an incredible trick of quantum mechanics that we only learned very recently, according to American researchers. In fact, the quantum trick forms the basis of photosynthesis, the process that turns light energy into fuel that supports most of life on Earth.

Strawberries in space

You’re speeding through the icy depths of space, millions of miles from Earth, when you realise you’d like a snack to remind you of the long summers of home. What do you do? Bizarrely, the answer might be as simple as going to pick some strawberries.