If I may I ask, what elements?
I think I summerize the main thought of the article is: we need to view animal happiness from the animal's perspective, instead of from the human viewpoint. The AWO shows some different perspectives on what we can and should do to make animals happy. It discusses some elements where there are ethical dilemma's about animal wellfare, like surplus animals, stimulating predatory animals without live prey, and how habitats should be constructed. I realise my quote might look like Blijdorp is saying: we need to do x, y and z to make the animals happier based on research a, b, and c. It's a bit less concrete than that, however they do give some examples of things they think might work.
It's a shame the article is behind a paywall. If anyone knows of a way I can share it with you guys without breaking ZooChat rules or bringing trouble upon ZooChat and it's moderators, please let me know.
A concrete example is giving about simulating hunting for otters without using live prey. Blijdorp is apparantly working on a mechanic system that makes (dead) fish offered as food, move around the enclosure realisticly to stimulate hunting behaviours the animal would also have in the wild.
There's also a bit more common examples where animal wellfare is improved, like the heated rock recently installed with the Asian lions
A less concrete example given is a discussion about how many space an elephant needs to feel happy.
Quote from the article: "
Bijvoorbeeld de olifanten, die in het wild gemiddeld wel 10 kilometer per dag lopen. ,,Er zijn studies gedaan bij olifanten en daaruit blijkt dat ze in een dierentuin even lange afstanden afleggen. Ik ben ervan overtuigd dat het bij veel meer diersoorten ook zo is. Dus dan is de vraag: wat maakt het dat wij ruimte vanuit onze menselijke perceptie zo belangrijk vinden?’’
(Elephants walk around 10kms per day in the wild. Studies amongst elephant populations have shown they walk just as much in zoos. I am convinced it's like that with many more animal species. The question is then: what makes it so that space is so important from the human perspective.)
Anyway, what I wanted to do with my last post is nuance the article title from looopings, because the article there left me with the impression: Blijdorp knows it's gorilla's are unhappy and does nothing about that. Instead, a part of the AD article discusses the problems faced in zoos where the current situation might be "OK" on physical wellfare: an animal is fed and dry and warm, but much is unknown about their mental health and if they are happy or not, or perhaps bored. A big problem is there's only little research done on animal happiness, because we're not sure how to research that.
The AWO says: "
Ik ben er echt van overtuigd dat wij als dierentuinen een bijdrage leveren aan natuurbescherming. Maar dan moeten we het onderste uit de kan halen om die dieren een goed welzijn te bieden. Dan bedoel ik echt kwaliteit van leven en een positieve mentale staat."
( I am convinced that zoos are part of nature conservation. But we should make a great effort to make sure those animals have quality of life, not only physically but also mentally)
So perhaps my last post didn't quite summarize the article very well

I'm always struggling a bit between giving too little information and talking to much
[Side note: good books I've read on researching animal wellfare are: "Zijn we slim genoeg om te weten hoe slim dieren zijn" by Frans de Waal, showing how researchers often forget to adapt an experiment to the way animals perceive the world, and "An immense world" by Ed Young, who reports on succesfull research showing us how animals experience the world. The latter one is a real eye opener.

)