If you'd like to participate in the discussion, but don't necessarily want to read the book - here's an overview:
When Elephants Weep Overview, taken from http://forums.about.com/n/pfx/forum.aspx?tsn=1&nav=messages&webtag=ab-biology&tid=1274
Anyone with any common sense knows that animals have feelings. But for over two centuries the concensus in the scientific world was that they didn't. Recently, science has been obtaining overwhelming proof that animals have feelings like we do. A good book on this subject is WHEN ELEPHANTS WEEP, THE EMOTIONAL LIVES OF ANIMALS, by Jeffrey Moussaieff Masson and Susan McCarthy. New York, Dell, 1995.
Charles Darwin was one of the first to realize that animals have emotions, and he wrote an entire book on the subject, THE EXPRESSION OF EMOTIONS IN MAN AND ANIMALS. But even he wasn't able to verify that any animals shed emotional tears and called weeping "one of the 'special expressions of man.'" He had heard reports, though, that newly captured elephants in Ceylon sometimes wept.
R. Gordon Cummings, an elephant hunter in Africa, shot a huge male elephant in the shoulder so it couldn't run away. He had a leisurely lunch as the elephant limped and leaned against a tree. Then, this hunter walked up to the elephant and fired bullents into various parts of the head. The elephant showed no reaction except to touch the bullet holes with his trunk. Then, the hunter decided to finish him off by firing nine bullets behind the shoulder. "'Large tears now trickled from his eyes, which he slowly shut and opened; his colossal frame quivered convulsively, and falling on his side, he expired.'"
Victor Hugo wrote about an elephant in a Paris zoo. "'The elephant in the Jardin des Plantes was slaughtered. He wept. He will be eaten.'"
In many Asian and African countries, animals are beaten or skinned alive before they are slaughtered, because it is believed this improves the taste. Recently, there have been complaints about a Chinese restaurant in San Francisco that boiled a coatimundi alive to make an expensive Asian delicacy.
Mother seals who see their babies clubbed to death by hunters shed tears.
Beavers caught in traps shed tears. Dian Fossey described a baby gorilla who saw his entire family slaughtered. He then spent a month in a tiny cage. When he was put in a pen where he could see the jungle he shed tears.
Sometimes deer who are pursued by hunters and their packs of dogs run out of breath. They look at the hunters, plea for their lives and shed tears. Then they are murdered by the hunters. Those who are shot with arrows may suffer in agony for hours.
Does an elephant or other animal have the right to defend itself and kill the hunter? I think so.