Mourning a loss is inevitable. As humans, we’ve designed rituals to help us cope.

Funeral rites have changed throughout history, but the purpose hasn’t. Funerals are there to help us mourn, to help us grieve, and to help us heal.

Humans were thought to be the only ones who mourn the dead, but scientists have recently observed that there are some animals that seem to mourn as well. Here are four animals that are thought to grieve when facing a loss.

1. Dolphins

Dolphins are known for being pretty smart. Studies have found that different species of dolphins “mourn” the loss of a dead companion. They will stay behind with a dead dolphin for hours — sometimes days — carrying the body above the water’s surface. It’s especially common for mother dolphins to carry the body of their young.

2. Dogs

Man’s best friend is believed to mourn just as deeply as we do. Not only do they mourn the loss of other dogs, but they mourn when an owner passes. Dogs have been observed to stay at an owner’s grave, sometimes refusing to leave. A study by the American Society for the Prevention of Cruelty to Animals (ASPCA) found that a dog can even lose their energy and appetite weeks after a death. Here are five dogs who were extremely devoted to their owners, even after they passed.

 3. Elephants

Elephants are another animal that is known for their intelligence. Scientists have found that elephants can experience a wide range of emotions from joy, to compassion, to anger, to love, and even grief. Elephants appear to deeply mourn the loss of another. A herd remains around the body of a dead elephant for a few days, almost resembling a human wake. Elephants also attempt to bury or cover the dead in brush.

4. Primates

Studies have observed behavior resembling mourning in different groups of primates, particularly gorillas and chimpanzees. Mother gorillas and chimps hold on to the body of their dead young for up to 24 hours, refusing to eat at times. Troops of apes gather around the body of a deceased ape, sometimes caressing the body. There also are instances of chimpanzees cleaning the body of a dead chimp from parasites.

Scientists are careful when it comes to saying that an animal “grieves.” What are your thoughts? Do you think animals can mourn the death of a companion? Or is mourning death a unique trait of being human? Share your thoughts with us in the comments below!