An orca named J35 has finally dropped her dead calf, which she'd been pushing with her head for at least 17 days and 1,000 miles off the Pacific Northwest coast, in an unprecedented show of mourning that drew international attention.

The sad spectacle was a prime example, and confirmation, of the complex emotional lives of these sophisticated cetaceans, experts say.

Other orcas, and similar animals like dolphins, have been seen apparently mourning their dead, but this is by far the longest recorded example of such behavior.

J35, nicknamed Tahlequah, is a 20-year-old member of the long-studied J Pod of Southern Resident Killer Whales. These orcas, along with their endangered extended family—K and L pods—inhabit a huge territory that includes waters