If deliberate burials are signposts of the belief
in life after death for humans, one cannot ignore
the elaborate burying behavior of elephants as a
similar sign of ritualistic or even religious be-
havior in that species (Siegel, 1977c). When en-
countering dead animals, elephants will often bury
them with mud, earth, and leaves. Animals known
to have been buried by elephants include rhinos,
buffalos, cows, calves, and even humans, in addi-
tion to elephants themselves (Douglas-Hamilton
& Douglas-Hamilton, 1975, pp. 240ff.). Etholo-
gists have observed elephants burying their dead
with large quantities of food, fruit, flowers, and
colorful foliage.- https://web.archive.org/web/20181118164741/https://pdfs.semanticscholar.org/f425/35b88e8e463117d8a54b70cd02f55f85f3a4.pdf
I've read this and can't stop thinking of the implications. Burying somebody with large amounts of potentially useful food makes no sense from an evolutionary perspective. Perhaps the elephants have weird reasons for doing this behaviour, but the simplest explanation does seem to be that they have some spiritual belief analogous to humans.