Sounds of the Earth. Communication between species (Part 2)

From the very beginning of time, the Planet Earth was not a silent place. And, as it was increasingly populated by living beings, these quickly learnt that sounds constitute an excellent means of communication.

Planet Doc Full Documentaries

Up to now, we have seen sound systems which convey information between members of the same species. But, around the planet there are cases of very different animals who have reached curious biological pacts in their calls, especially those of alert; one such example is to be found here, in India.

The chital is a type of deer which lives in this region and which likes to graze alongside curious simian companions, the langurs. 
The reason for this is that the langurs have organised a very efficient system of surveillance, based on lookouts posted up in the treetops, who are in permanent visual contact with each other.

The langurs have very good sight, but when they come down to the ground in order to complement their diet, they lose the advantage of perspective and become vulnerable. Therefore, with the reassurance of the sense of smell and the hearing of the chitals, they feel safer. Both species need to be constantly on their guard, because they share their forest with the greatest assassin in Asia, and both of them form part of his usual menu .

The Indian tiger can reach up to 260 kilograms in weight, and so despite their cryptic markings it is difficult for them to go unnoticed when they move.
Above all if there are sentries in virtually every tree in the area. When a langur spots the tiger, it sounds the alarm.
This association between langurs and chitals, along with other factors, means that the tiger only kills once in every twenty attempts, and often forces the great hunter to travel over twenty kilometres in search of prey.

On the other side of the world lives an animal whose screams also help it survive. The Tasmanian devil is a carnivorous marsupial who loves eating carrion. It is not a very large animal, and nonetheless it has a very bad reputation; even its name would be an exaggeration if it were not for the noise it makes.
The first Europeans to arrive in Australia heard terrifying grunts in the dark of night and thought they were produced by a terrible, extraordinary animal, a devil; hence the name.
The fact is the Tasmanian devil has a very bad temper, and when two of them meet over a dead body, they settle their differences by screaming at each other.

These exaggerated snorts serve to avoid real fights between rivals, who could seriously harm each other with their powerful fangs. In reality, they do not even touch, the one that screams loudest will win the fight, and both will escape without even a scratch.

If the devils really attacked each other in these clashes, they would inflict numerous wounds, and even the winner might well die from a subsequent infection. Therefore, natural selection has favoured screams as a survival factor above real physical aggression. 

Up in the Indian Himalayas lies the Ladak Valley, called “Little Tibet”, as it is the home of Tibetan spirituality and culture in exile. 
At the Monastery of Lamayuru the annual festival of dances called “cham” is about to begin.

The dances that are about to begin represent the fear of demons. The dancing monks will capture the malignant spirits with a bowl they carry in their left hand. 
Each sound and movement has its meaning in favour of the protective gods who work against these evil spirits. 
The origin of the dance is the Bon Chos, an animist religion which existed before Buddhism, and which has left this legacy which the monks incorporate as a metaphor of the gradual conquest of the Ego, the final aim of Buddhism.

Tell us what you think!