Walking a dangerous metaphorical tightrope I would make the following points on this matter:
1. To date Jane Doe's posts have indicated that she is short-sighted (not really considering the subtleties or the "big picture" of issues) and has a monochrome view of Twycross (old regime faultless, new regime wrong). In short, in my opinion, she's been a zealot who has completely ignored blatantly obvious points and and not properly considered facts which do do fit her (pretty much entirely wrong) viewpoint;
2. That said, liked stopped watches, even zealots are capable of occasionally making points which may prove correct or, at the very least, require a little further consideration;
3. From my perspective, it would seem that, empirically, there's been a number of animals that were both seemingly "cage blockers" and were PTS on medical grounds over the last 18 or so months. These include (at least some of) the Sea Lions, the Wild Cats, the Camels and now Smiler and Jane (I've got to say, it seems sadder when you know the names of individual animals). Please people feel free to correct me if my recollection is wrong or I have missed any animals;
4. To be fair, it's entirely possible that similar levels of seeming "cage blocker" animals would have been PTS at other collections over the same period of time. It may just be that, as Twycross is the closest (geographically and otherwise) collection to me, I notice the comings and goings and animals there more than I would elsewhere. This may also be an issue from Jane Doe's perspective;
5. It's interesting to note that, as far a I am aware, most of these were not "studbook animals";
6. Personally, at this moment, I'm not sure how I would feel if, as seemingly alleged, some of these animals were PTS for "convenience". I generally don't have a problem with culling as a species management tool (excess male hoofstock, for instance) but the possible/allleged Twycross scenario is a little more subtle than that;
7. On the surface, regardless of the motive for the animals being PTS, it would seem that a seeming large number of animals have recently been noticed as "unhealthy". This raises the question of whether animals' health has been properly monitored just prior to most recent times or whether it's just the natural result of a collection that holds a considerable proportion of very old animals;
8. Realistically if Jane or Smiler needed to be PTS for health reasons there is a reasonably strong argument, given their age and close bond, that it would be humane to euthanise them both;
9. I wonder (without judgement), as I'm sure others will, whether economic circumstances informed the decisions in any way. Zoos don't have "pet insurance" on their animals and they can't justify spending a fortune on keeping an elderly animal alive for a short additional amount of time just because members of public might have emotional attachments -this would be economically and, arguably, ethically wrong.
In summation, I'm not concluding on the matter except to point out that there are a number of subtleties to consider. It is a complex, not straightforward, matter and being quick to judge (either way) without considering all angles (which we may not be aware of) is too easy and wrong. In my opinion, it might be that in this situation any action is likely to be considered right by some and wrong by others (especially when nobody on Zoo Chat is likely to know all the relevant facts).