Some of his fellow celebs reacted in horror to news footage showing the carcasses of some 50 escaped exotic animals police in Zanesville, Ohio shot to death this week out of concern for public safety.
But given his activism on behalf of tiger conservation, Leonardo DiCaprio was especially broken up over the slaughter.
The "J.Edgar" star took to Twitter to mourn the loss of 18 rare Bengal Tigers among the fauna that authorities were forced to kill Wednesday after their keeper released them into the wild before committing suicide.
"Sad situation & proof we need better regulation to protect both animals & people NOW," tweeted DiCaprio, before linking to a CNN story that quoted Muskingum County Sheriff Matt Lutz as saying that all the critters were accounted for following officers' search (and destroy) mission.
The 36-year-old thesp subsequently sent a follow up tweet urging followers to join the World Wildlife Fund's Conservation Action Network, for whom he lent his good name to help kick off its Save Tigers Now campaign in May 2010.
There are approximately 3,200 tigers remaining in the wild, and the species is teetering on the brink of extinction due to the threat of poachers who kill the 300-pound endangered felines for their pelts and other parts, and the ever-increasing loss of their habitat.
DiCaprio's call for improved regulation over the trade of exotic animals also jived with a statement released by PETA that called the Zanesville massacre "a tragic example of just how wrong things can go when people are allowed to keep wild animals."
Police still have no official word on the escaped monkey that had the herpes B virus, though Lutz said his department believed one of the big cats could have eaten it.