The Reticulated Giraffe
The incredible actions of termites nurture grasslands all over the world… Including Kenya's whistling acacia savannah. Here the impact of termites goes
right to the top… All the way to the world's tallest land animal. when I was a child, we thought there was just one type of giraffe,
but now we know there are six different species. This one's a reticulated giraffe. He can reach anything, but of all the plants here, he's chosen to eat
whistling acacia tree. But just look at it!
Thorny Acacia Tree
It's one of the best-defended plants in the whole of Africa. But why are these trees so well armed against browsing animals like these giraffes? Well,
the answer you won't be surprised, comes down to nitrogen. You see, these trees' leaves are absolutely packed with nitrogen. That's why they are the
botanical equivalent of Fort Knox. At the base of many of these acacias are colonies of African termites. The acacias' roots boring under the mounds,
tapping into a rich well of nitrogen. As a result, these acacias become an oasis in the nitrogen desert. So it's really no wonder that the thorns alone
don't deter giraffes from tucking in. So, not to be beaten, the tree employs another line of defence, its own private army.
Now, just watch this. I'm going to pretend to be a giraffe browsing on this branch here. So I'm going to pull at the leaves, shake it about a bit, try and not
get jabbed by the thorns here. But just look at this. Very quickly, a whole mass of these Crematogaster ants swarm out and cover my hand. And I can tell you
that, if you are a giraffe browsing on this, you wouldn't want these things all over your tongue. Each ant is armed with a chemical weapon. It's capable of
squirting venom. Each gall houses a separate colony of ants, and each branch might have a dozen or more of these galls.
So the only way a giraffe can get in ant-free meal is to grab a quick snack and then move on. The tree has evolved to produce these hollow thorns, and
they have the perfect structures for the ants to make their colonies inside. And in return for the plant's investment, it gets these insects as vigorous
defenders. But this is just the beginning of a truly amazing web of relationships.
These are Patas monkeys. As grassland specialists, they're the fastest-running primates in the world. In the 100-metre sprint, they beat any Olympian by
three seconds. To fuel their energetic lifestyles, their favourite food is Crematogaster ants and their larvae. The trick is finding them in just the right
position. He could easily have his eye out on those thorns. Once ripped open, the ants abandon the gall, but this act of primate vandalism only serves to
enrich this mini ecosystem.
You see a short while later, a new occupant has moved in. Here, protected from predators and the harsh sun, a dwarf gecko has
laid two eggs. Because she isn't a threat to either them or the acacia, the ants mostly ignored her.
After four months, a perfect miniature gecko hatches out. It's completely defenceless, but luckily, it's found itself in the perfect nest. It
couldn't possibly appreciate all of the creatures here on the grassland that have come together to put a safe roof over its head.
The giraffe eats the acacia tree, so it continually produces those galls which form the geckos' home. The acacia tree needs the ants to protect its
leaves and keep it healthy, and in turn, the Patas monkey needs those ants and their larvae as food. And all of this can only happen because the tree
has managed to accumulate nitrogen from the grassland that's evolved to prosper despite the fact that this element is always in short supply.
It's often said that you can only tell who your real friends are in times of need. This is also true in nature. You might ask if it really matters if an
animal becomes extinct. Well, so intricate and the connections in the natural world that there is no way to predict the impact of adding or removing
species until it's too late.
Who would have thought that a bettong would need a bandicoot, that the leaf-cutter and would need a maned wolf, or, indeed, that the gecko would need a
giraffe? No, the complex web of relationships that we've seen have evolved over millions of years, but we've only scratched the surface of a myriad of
stories that, when they come together, make these grasslands functional ecosystems, and it's here that I've learnt to see the real beauty in nature.
You see, for me, it's not the minute detail. It's in the bigger picture. Because this works perfectly, and that is beautiful.