Yes I will reflect on this. If you are talking about a situation where the poor health or injury is due to human accident, carelessness, intervention or whatever, then one can certainly argue a “moral” or “ethical” basis to euthanase. If it can be treated, that is even better and there are any number of good stories of wildlife carers who have done great jobs in this way. Whilst it is best to remove damaging tangles if possible, some birds are able to survive after losing toes or a foot. Sometimes to do so is unachievable. To that extent what you write is probably true. However to suggest that every animal found in terminal difficulty must be euthanased I think is odd and impractical and goes against that we should not interfere in nature. Deciding on what can or not survive is not always so clear. Some injured animals can be maintained in captivity quite well and be used for breeding, education etc. This is often true of raptors.
To remove the individual from the ecosystem in the way you suggest, by removing the opportunity for predation on that animal, by another animal, may be counterproductive. I suggest in most cases it is better that an injured animal be taken by a predator, if that is a likely possibility, and thereby maintain its place in the ecosystem, than to be removed by people who are. Otherwise the predators would just find someone else to eat. Unless of course the injury is due to poisoning that can be passed up the food chain. If an injured animal is in terminal pain and can be captured without great stress and euthanased humanely I would often agree with you. Apart from that, regardless of whether or not it is humane to leave an animal to die of infection, starvation or predation, that is the natural system that has happened forever and it is not (necessarily) our role or ability to “play god” and terminate it or to make the decision to take its life.
Philip
