@gentle lemur: Sorry for the slow reply, but thanks for your thoughtful response.
a) Listed buildings: there are three Grade II listed buildings at Bristol Zoo, the two entrance buildings and what was the Giraffe House. The South Entrance is now closed, but the architecture is preserved. The Main Entrance has been modernised and extended inside the zoo, but the external facade is unchanged. The Giraffe House was modified when an extension was built for elephants (in the 1960s I think) and again when the gorillas moved in and the last elephant went across the house and then being replaced by okapis. In 2012 the interior was imaginatively reconstructed to provide more space for the gorillas, without altering the external structure. Surely the Casson elephant house and the Mappins are prime candidates for similarly radical internal adaptations: imagine the interior of the elephant house hollowed out and spanned by a walkway over a manatee pool; imagine the whole inner section of the Mappins changed into a shallow slope for a herd of antelope, leaving the four artificial mountains as the skyline: of course such projects would need careful negotiations with Historic England and a good deal of capital, but Bristol's experience shows that neither of these are impossible.
To steal an Aaron Sorkin-ism, this is like comparing driving to the shops with going to the moon. The Casson and especially the Mappins are on a different scale to the challenges Bristol faced. When we consider like-for-like, London has renovated its historic structures just as well as Bristol. The Blackburn Pavilion is brilliant. The Terrace Restaurant is tasteful. The Giraffe House is pure magic. We’ll see whether the much larger Snowdon Aviary project is also successful, but I don’t think “Bristol did something well, so London can do something vast” is a fair argument.
b) Modifying older buildings: the conversion of Bristol's old bear pit into an Aquarium is another example of using an existing space imaginatively. The result may not be absolutely ideal, I have never liked the walk-though central tank, but the other exhibits are very good. I also like Bug World, where a range of good exhibits have been fitted into an awkward space - B.U.G.S may be a nicer building, but the exhibit quality is weaker in my opinion. The conversion of the Sobell Pavilions into Gorilla Kingdom doesn't seem to work well for either the gorillas or the visitors and the other species seem to be random leftovers. It is only fair to add that both zoos still have spaces that could benefit from renewal, such as the North Bank at London and the interior of Forest of Birds and Smarty Plants at Bristol (I do hope they demolish the old Monkey Temple before some fool suggests listing it too). Let us hope that the work goes well at Zona Brasil and the Snowdon Aviary.
Again, I think you’re being too hard on London. B.U.G.S., in my opinion, is the best zoo exhibit in the UK. It’s architecturally striking, innovative, genuinely educational, and exciting to boot (spider walk-through!). I wish the rest of the zoo were built in its image. Bug (
sic) World is also very nice and the behind-the-scenes work is stellar, but parts are a bit tatty and I don’t understand why you think it’s a better display.
Bristol wins on gorillas, I agree, but aren’t we forgetting about lions? Whatever your gripes with Land of Lions, you’d be hard-pressed to argue Bristol’s enclosure comes close. London also has very pleasant exhibits for tigers, penguins, squirrel monkeys, pygmy hippos, etc. And the oft-heard argument that Bristol’s developments are more tasteful was debunked when they added a high-ropes course and crashed airplane.
c) Use of space: both sites have limited space, but virtually all the space at Bristol is used and cared for: the latest development being the conversion of a small area beside the giant tortoise paddock into an Asian Turtle Breeding Room. ZooChatters might think that too much space is devoted to play areas, gardens and lawns, but they all seem to be well used and appreciated by visitors. I understand that London needs trees and shrubs to screen parts of the zoo from the Outer Circle and Regent's Park, indeed some spaces like the steep canal banks can only be used like this, but there are lots of small areas between existing exhibits that appear to be unused and unloved. London Zoo seems to have lost interest in planning and building new small exhibits, and even in looking after the ones they have. The outdoor enclosures at the Round House end of the Clore are overgrown, so is the Komodo dragon outdoor exhibit, and the windowed exhibit in the south wall of the Reptile House is boarded up. Am I being unfair in wondering why more care seems to have been taken in arranging the display of flip-flops at the fake shoe stall in Land of the Lions than in designing and maintaining the neighbouring mongoose exhibit?
London does need filling out, but they recently added gibbons and Bristol could have more exhibits, too (e.g. your suggestion of replacing Smarty Plants). In general, I agree that ZSL should make smaller projects and general maintenance a higher priority.
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Ultimately, I think London and Bristol have similar strengths and weaknesses, hence my initial objection. Strengths: a rich and evident history, sensible collection planning, a commitment to displaying taxonomic diversity, and very successful conservation/research programs. Weaknesses: limited acreage, wasted space, small all-indoor exhibits, and tack. London also has its architectural white elephants; I hope you’re right and they can switch from a weakness to a strength.