I just found this article about dolphins' funeral captured in the East Sea, Korea in June 27, 2008. The dolphins are a group of common dolphin (Delphinus delphis) and one of their friends was about to die.
The article says only few dolphin funeral has been reported and one of them is a wild baby dolphin is pushed up surface by its mother for 5 days. What they do is trying to help the sick one breathing better, the scientist says.
The researchers took 2 hours of footage of this event and found later the dead female dolphin didn't have any wounds regarding it was a natural death. Dolphins live about 30 years.
The original Korean article including part of the footage can be found on http://www.donga.com/fbin/output?n=200809100417&top20=1
