Can emotions help animals make choices?

Can an animal living in a world threatened by predators develop a negative mood/emotion? Or vise versa for animals with plenty of opportunities to acquire meals, water, shelter, etc have a positive mood?

Researchers say that emotions not only show the animals experiences but how it makes it choices throughout it's life. Take an elk for example; whenever an elk hears a sound it immediately thinks of danger which would be a "safety-first" response where as whenever a grizzlie or a wolf hears a sound it immediately thinks of prey which would be a "optimistic" response.

I guess that stands true for humans to because if you get picked on a lot a certain way such as being pushed up against a wall near certain groups of people you start to avoid those people as much as you can and when you see them you try to get away.

http://www.sciencedaily.com/releases/2010/08/100803212013.htm
I just think that this makes sense to me