Great thread p@m.
This is a very emotional and debatable question…
why do whales beach themselves?Let’s start of by asking the question…
Why do whales die when beached? The smallest species of whales weigh in at several tons. They die from overheating and from the crushing weight of their bodies. Usually the whale’s body weight is too much and that suffocates it with its respiratory muscles incapable of sufficiently dilating its rib cage to ensure adequate pulmonary ventilation.
Also, circulation of the animal's body that is in contact with the ground is blocked by the animal's weight, causing tissues to die.
Whales on the beach struggling to survive are not a pleasant experience, and people are very emotional about this issue trying to save these beached whales. Even if the animal is returned to the water, these dead tissues may produce toxins leading to generalized infection and death.
In many instances whales will return beaching themselves after been saved, and believes are that they return due to the distress calls from the other whales still in distress. Whales are highly social animals.
There are no easy answers to the question of why whales beach? Many causes have been researched and one explanation involves the whale "pod" social structure. Whales traveling in pods use a "strength in numbers" survival strategy, but this can backfire when the dominant whale runs aground. A disoriented or sick dominant whale may be followed onto the beach by the rest of the pod or a pod may venture too close to shore and become trapped by the tides.
Other theories suggest that defects in a whale's navigation system may be the cause of whales beaching, but the fact is that we do not know how whales navigate the vast oceans….it seems to be a very speculative issue.
The fact is that whales do not beach to commit suicide. Although highly intelligent, it's believe that whales do not have the mental capability to understand a concept like that!
(Sources:
http://www.thecryptmag.com/Online/32/WhaleBeaching.html ,
http://www.physorg.com/news128351475.html )