Elephant Mourning

Many people seem to think that humans are the only animal capable of mourning the lose of a loved one. This appears to not be the case. Elephants have been studied for their cognitive abilities, dexterity, their memory, and for their emotional complexity, among other things.  

A lot of evidence has come out which shows that elephants have the capacity to mourn the death of their clan members. Not only do they show signs of bereavement, but in accordance to their prolific memories, they are also known to revisit the death site of former clan members, as well as following ritualistic practices when coming across the bones of their fellow members. National geographic has a short clip which shows several elephants finding the bones of their former matriarch. I have linked the video here. The loss of the matriarch is seen as especially traumatizing, as they hold the collective knowledge of the extended families territory.

Grieving Elephant

They show signs of mourning in a variety of ways. They have been observed staying at the body of the dead family member for several days, prodding or poking at the deceased elephant with their trunks, heads or feet or making audible cries or calls (of distress). Some will return to the site of death after the death, and have been known to return even in later years, stopping to pay their respects at the site to "pay homage" (citation). After a loved one dies, it has been observed that there can be a change in body language and personality for several days while they grieve, especially mothers when their baby dies. Calves have been known to die from grief after their mother dies.
(picture citation: http://camilaruz.files.wordpress.com/2011/05/elephant-grief.jpg)

In a recent case in Borneo, 10 pygmy elephants were found dead (likely poisoned) on a farmers field. They were found after being dead for close to three weeks. When authorities discovered the dead elephants, they also found a 3 month old calf "trying to use its trunk to nudge its mother awake". According to an article written the Digital Journal, elephants are "reportedly the only other mammals besides humans known to mourn their dead". They also attend to their sick and dying clan members.   
Poaching, environmental degradation, farming casualties, and environmental changes are taking a toll on elephants, not only in population sizes, but emotionally as well. Not only do they lose a member of their life long community but they also feel a communal, tragic loss with each death, be it from a natural death or at the hand of a human.

Elephants maintain friendships for life, and evidently after death as well.  

Sources:

http://video.nationalgeographic.com/video/animals/mammals-animals/elephants/elephant_african_mourning/

http://digitaljournal.com/article/342421

http://elephant.elehost.com/About_Elephants/Senses/Grieving/grieving.html