It has long been known that certain animals (like elephants) seem to recognize and even mourn the passing of a friend. According to this BBC report, that may be a trait may reach into species not considered highly intelligent. This study is a reminder that the clear line we discern between humans and the other animals may exist only in our heads.
“The jays then gathered around the dead body, forming large cacophonous aggregations. The calls they made, known as “zeeps”, “scolds” and “zeep-scolds”, encouraged new jays to attend to the dead.”
http://www.bbc.co.uk/nature/19421217