I had no idea they were so common in Europe before, but it's a shame that they are quickly disappearing there. From what I've seen, a similar trend is happening in North America where only a handful of zoos left have hummingbirds on display, and mainly native species.
Until a few decades ago hummingbirds were much more common in zoos. Check the remarkable
hummingbird species list in European zoos by zootierliste and in all probability it is incomplete because few of its users spend time putting in historical species. There are probably more (Japan?) but Jurong is the only Asian zoo I can think of with hummingbirds and they
may not have them anymore. Back in the 1970s and earlier serious attempts of starting breeding programs were far between because the general mentality often was different and wild were so easy to import. Then all hummingbird species -common, rare and everything in between- were listed on CITES. This effectively stopped almost all legal exports of hummingbirds from their native countries. Except for the occasional customs seizure of illegally smuggled birds that are moved to zoos for safe keeping (this is how Avifauna got their unusual species), the few species that remain in European zoos are all very common species that were kept in large enough numbers to get some breeding started. Much of this was only thanks to a few private breeders. I wouldn't be all that surprised if some of these species disappear within the next decade or two. I guess it was also this realisation that prompted Walsrode to built their hummingbird house in 2011, which has big off-show facilies aimed at breeding. There is also a scientific hummingbird center in Trieste, Italy, which is the source of some (all?) of Walsrodes hummingbirds. I don't know much about it but based on their
facebook page they do have some breeding success and also keep species not kept elsewhere in Europe. I presume they don't have them all anymore but in this
video from 2008 you can see at least seven species: Sparkling violetear (several times, e.g. 52 sec), Purple-throated carib (several times, incl. nesting in start), Buff-tailed coronet (several times, e.g. 30 sec), Amazilia hummingbird (2.41), Chestnut-breasted coronet (several times, e.g. 2.37), Ruby-topaz hummingbird (2.48) and Reddish hermit (2.50). Their facebook gallery started in 2010 and if discouting the photos that were taken on a trip to Ecuador it has three additional species: Green-tailed trainbearer, Purple-collared woodstar and a big hermit I can't identify (long-tailed?).
On a related note it does bug me a bit that most zoos keep hummingbirds in tropical rainforest exhibits. None of the species that remain in more than one zoo are from this habitat:
-Amazilia hummingbird: usually dry to semi-dry woodland and scrub. Tropical temperatures.
-Ruby-topaz hummingbird: usually woodland and scrubland. Tropical temperatures.
-Sparkling violetear: usually highland woodland and scrubland. Subtropical and temperate temperatures.
-Green-tailed trainbearer: same as Sparkling violetear.
-Species native to USA.
Considering that hummingbirds probably are most famous for their small size, it is also interesting that the ruby-topaz is the only species kept in Europe that belong to the smaller species and it is still quite a bit larger than the absolutely smallest.
After visits to Ecuador and Venezuela I was amazed by the diversity of hummingbirds and will never forget the remarkable
booted racket-tailed (tiny if discouting tail extension),
violet-tailed sylph,
crimson topaz (second largest hummingbird),
tufted coquette (tiny) and
sword-billed hummingbird (longest bill to body ratio of any bird). Species that, despite being widespread in the wild, probably will never appear in zoos again.