There is no clean cut and dry statistic that I can find to answer your question. When comparing domestics to feral, so many variations can come into play depending of course just the type of animal in the first place. Let's look at cats.
I found a great article here called "Consider 1000 owned cats vs. 1000 stray/feral cats" at this site. fanciers.com/npa/owned-cats.html The opening of the article states that the average life span of a domestic is about 7 years, where a feral cat will live about 3 years. I could not find any stats on general causes of death.
There is much more information that will hopefully help you at this site.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.