I asked for the most part same question not too long ago.
http://www.fluther.com/disc/76438/cando-animals-commit-suicide/
It is hard to say honestly….
But there are important distinctions people need to realize
-What level of awareness do other animals have?
-Do they understand death?
-It is important to separate what you think is an animal killing itself and an animal that indeed truly killed itself.
-It is important to also notice, did the animal kill itself on purpose?
The definition of suicide or least I am pretty sure is basically“Suicide is the intentional killing of oneself.” Intentional
The examples of birds flying in cars , whales beaching them self , lemmings ,etc…..
The bigger problem I see here is that as humans and yes we are animals but there is one important difference in my opinion.
We have been taught and have come to learn about not doing dangerous,stupid, and otherwise death threatening things.
If a human were to walk across the street and not see a car , get hit and die? Did he/she kill himself?
or a young human, child goes into water too deep and drowns.
A group of people in panic on a hillside from some disaster one falls off in the fray of things.
Are we going to say they killed them self, you might say a lack of knowledge, a mistake, stupidity even maybe. But intentionally I would say no in those cases.
http://en.wikipedia.org/wiki/Instinct
Another problem I have with different animals is how much is based off instinct which is basically “Instinct is the inherent inclination of a living organism toward a particular behavior” for example the lemmings myth is in my opinion an unfortunate back fire of evolutions conditioning and instinct to lemmings.
Anyways I suppose I’m going off topic now, but to your main question do I believe animals can kill themselves? Sure I believe so.
But do they understand,aware, or realize that by doing these actions results in death the end of your existence as the animal and we know it….
Now that is a real mystery,least for me, that seems rather impossible to answer I think….For now anyways.