Of course a wildlife refuge would be ideal, so would having ten million dollars to spend on it. Yeah it sucks, we just don't have the resources for it. Personally I feel just letting nature take its course or natural selection is fairly irresponsible on our part, I couldn't in good faith let animals die that I know could of been avoided. Sadly it does happen, even in a wildlife refuge, case in point; About 30 miles north of where I live in Dallas is a big cat sanctuary. Usually they come from people who illegally purchase them, attempted to smuggle a cub into the country, or someone came to the harsh realization that this big boy could easily kill me just playing around. Roughly 3-4 years ago a case of Canine Distemper broke out, when it was all said and done they had lost 7 big cats. Of course people immediately started pointing their finger, protesting the sanctuary saying "See, see, you killed those animals by keeping them in captivity!". Without knowing the circumstances mind you. When actually a lioness they had received from Mexico, presumably from a drug dealer, had just been infected prior to the transfer. It was a incredibly sad situation, however because they were able to see the stages of the illness take hold, a vital piece of research was discovered to make the first known vaccine. It's still in the development stage but it's a start, it's very sad a mix of seven species of big cats had died. However with this vaccine looking to be widely used, it will prevent other big cats in the wild from meeting the same demise. Such as in 1995, in the depths of Tanzania, over 1000 carcasses Lions and Lioness had been found, all died from Canine Distemper. Hopefully this won't ever happen again, and a catch/vaccinate/release will be implemented.