Elephants have demonstrated a wide of array of empathetic traits, including refusing to leave behind sick family members. Now this sort of behavior seems to extend to elephants beyond the immediate family.
Filmed in 2003 by Shifra Goldenberg, a Colorado State University doctoral student, this video shows three different groups of elephants inspecting the remains of Queen Victoria, a 55-year-old elephant who died of natural causes in the Samburu National Reserve. As Goldenberg told National Geographic, "What the family was doing was interesting, but what her non-relatives were doing is also important. You see their investigation of the body. You see calves walking past and smelling it. It is amazing to see that level of fascination. Her family was distressed that she wasn’t getting up. But the larger population also was interested in her death."
Perhaps the most heart-tugging part of the video is Goldenberg's explanation of the temporal gland secretions, just before the two-minute mark. She discusses that such secretions only occur in times of stress and elevated emotions. To see such a response from elephants that aren't even a part of Victoria's family may not indicate mourning as we conceptualize it, but it does seem to demonstrate the intense social bonds that elephants develop with one another.