So, what next?
For an act to be classified as a suicide, the agent must know that what it is doing will end its life. It is impossible to tell if any non-human animal knows its actions will result in its own death and performs the actions towards that end.
The closest today is the phenomenon of dogs that will sometimes refuse to eat after losing their masters, which does in rare cases continue to the death of the dog. But the question remains in these cases- is the dog refusing to eat so that it will die, or is it just refusing to eat because it’s sad and has no appetite, as can happen with humans, but in the dog’s case not realizing the potential consequences?
There are several types of insects who willingly allow themselves to be killed, or even in a few cases, do the deed themselves.
For instance, it has been noted that certain species of ant possess the ability to explode themselves at will when threatened (often emitting some sticky or poisonous substance in the process), earning them the apt nickname of “exploding ants“. However, even if the ants realize what will happen in terms of their own existence, it would not be classified as suicide anymore, the ant sacrifices itself for the greater good because as a species, it’s evolved to put the needs of the many before the needs of the individual.
Similarly, honey bees will willingly explode their own penises and subsequently die, just for a chance to pass on their genes. They will also willingly remove themselves from a hive if they know they’re infected with a disease that could potentially hurt other bees.
In short, though we’re aware of numerous cases in which animals have seemingly intentionally taken their own lives, we simply don’t know whether the animals understood the ramifications of their actions, or were just reacting to environmental triggers without much thought going into it.
Most of us overcome these worries. We have an in-built optimism bias, which gives us a rosier view of the future, but this is not the case for those with depression, for whom the future often appears very bleak.
The vast majority of cases are down to human intervention in some or the other way, whether the result of poaching or confinement.