Scientist/biologist have had many sightings of different species that suggest various animals, marine life, fowl etc also grieve, just like humans.
Studying the intriguing life of animals, biologists have found that similar to humans, animals have strong bonds with others, and when experiencing a premature death, or a death, animals also pine for the dead.
Animals, such as elephants, gorillas, dolphins etc lead rich emotional lives and they too can act depressed by not eating and at the risk of starving themselves because of their grief.
We're learning more and more about animal behavior, including what some scientists believe is grief.
Witnessing animal death rituals makes me a true believer that a lot of different species also feel grief, and therefore, I feel they are great teachers for us humans to recognize that grief is a natural and normal emotion, regardless of what living being one is.