Some time ago I wrote a paper in which I presented the following thought experiment: Suppose there is a rabbit and a fox that is about to capture and eat her. We are witnessing this, and we have two rations of vegan food. We consider what to do. Among the different ways in which we could act there are the following three ones: (1) We eat one of the rations of vegan food and see how the fox catches and eats the rabbit. (2) We give the fox one ration of our vegan food and we kill and eat the rabbit ourselves. (3) We give the fox one ration of our vegan food, we eat the other one and the rabbit runs free to live her life. The paper discusses what should we do in a situation such as this. It concludes that we should be concerned with all the harms that nonhuman animals suffer, including those which aren’t caused by humans, but for what can be called «natural reasons». You can see the paper here:
The paper has been published in the Brazilian journal on animal ethics Pensata Animal (which includes texts both in Portuguese and English); the published version of the paper can be read here (although this published version has some mistakes which you won’t find in the version of the paper I linked above). This journal has included an interesting section (in Portuguese and English) in which different articles deal with the problem of wild animal suffering, predation and intervention in nature for the sake of nonhuman animals.