biologizeable:

Shingleback Lizards

“When spring returns, the same male and female will seek one another out, and mate again. In fact, a pair will remain faithful to one another for as long as 20 years or more. The bond between them may even endure after death. They’re slow-moving creatures, and only too often when crossing a road they’re unable to get out of the way of a passing car. If one of the pair is run over, the other will often remain at its side for days, tenderly nudging it. You might even say that it was grieving.”

(BBC Life In Cold Blood)