De la soul buddies, four legs high in rising

Grieving dog refuses to leave companion

A heartbreaking photo on the Web shows a pit bull who sat at his dead companion's side for hours. Dog looks 'very sad'

Damini would stroke her pregnant friend's stomach with her trunk 

Elephant dies of grief

Watch Wisdom of the Wild on PBS. See more from Nature.

Mike Lovett/Brandeis University

Alex, a 31-year-old African gray parrot, knew more than 100 words and could count and recognize colors and shapes.

Brainy Parrot Dies, Emotive to the End

... As she put him into his cage for the night last Thursday, she recalled, Alex looked at her and said: “You be good, see you tomorrow. I love you.”

He was found dead in his cage the next morning, Dr. Pepperberg said.