The Whistling Thorn Bush of Africa is covered with, you guessed it, thorns. A shrubby bush, it is the home to an assortment of birds and insects on the plains of Africa.
Elephants, giraffes and other browsers eat the leaves of this thorn-bush. Elephants especially, will ravage it tearing branches off and stripping them completely sometimes just leaving a stump where the bush had been.The thorn bush has developed a defense mechanism that was explained to me during my trip. The bush produces galls, marble sized balls growing along the branches in between the thorns. When the galls mature, they become homes to ants.
The ants bore a hole in a gall and the hollow ball becomes a busy den, every six inches or so along each branch. The holes the ants create make whistling noises when the wind blows through them, hence the name.
When an elephant begins to eat the small leaves of the bush, the ants come pouring out of the galls and produce a chemical on the tips of their abdomens that burns and irritates the lips and trunks of the elephants. The elephants have learned to leave them alone or be very careful, one of the two.
Symbiotic relationships between living organisms is not uncommon. The Boxer Crab carries around a pair of small anemones in it’s claws. When approached by a predator, it waves the stinging anemones around like weapons. The predator backs off and the anemones get to pick up small pieces of food lost by the crab.