Before we get going, I think it is good if I briefly explain the format of the posts in this thread. Might not be the most exciting, but it should answer questions that would otherwise be answered later.
The format
The bulk of the posts will be the different order, family and species accounts, each following their own pre-set format. Orders and families themselves will be covered briefly and the bulk of the text is devoted to the species accounts. Posts will typically cover only 1 or a few families, though very speciose families like bovids (
Bovidae) will be covered in multiple posts.
Each family post will be divided into a maximum of 6 categories depending on the covered species. Only family members that clearly fall into one of the categories will be treated. So both very common and very rare species can go unmentioned as long as their numbers have been more or less stable throughout the century. Each species gets a short piece of text with the most important data such as holding dates, some zoos which held/hold the species and (possible) causes for the noted trend. The categories are the following:
Species gained
For species that only arrived in Europe this century and are still currently kept. This does include species that were already kept at some point in the 19th or 20th century, but were subsequently lost.
@RatioTile The Maleo returned to Europe after 30 years of absence in 2018
Species gained but lost
These are the species that only arrived in Europe this century, but have disappeared again and are not currently kept anymore. This can include species that were already kept at some point in the 19th or 20th century, but were subsequently lost and are now lost again.
@gentle lemur Tiger quoll were only kept in Hamerton Zoo form 2018-2022 this century
Species lost
For species that occurred in Europe at the start of the century, but aren’t kept anymore currently. This can include species that were present in 2000 and then disappeared, to reappear and then disappear again.
@Gondwana After being present for decades the klipspringer disappeared from Europe in 2022
Species gaining popularity
These are species that have been continually kept this century but have seen a marked increase in popularity, most often due to the net number of holders rising, but in a few cases I have included future interest too. This category is not exhaustive, partly given the lack of arrival dates for some zoos. While not exhaustive I think the included species give a good overview of the trends currently at play. I did not use any fixed criterion to determine a marked increase, though in some cases I have tried to underpin the increase with a number, but in other cases that was just too difficult, even though it is clear the species is gaining popularity. This does also include species that are now significantly more common than in 2000, but have lost popularity in recent years.
@Julio C Castro Few mammals have seen a larger increase in number of holders than the giant anteater
Species losing popularity
These are species that have been continually kept this century but have seen a marked decrease in popularity, most often due to the net number of holders declining. In a few cases I have included species here where the number of holders hasn’t declined yet, but is widely expected to do so very soon. This category is not exhaustive and I did not use any fixed criterion to determine a marked decrease. Nevertheless this category should give a good indication of which and what kind of species are losing popularity.
@Andrew_NZP Kori bustards are having a hard time in Europe at the moment
Dead ends
This category is only for species of which it is nearly 100% certain that they will disappear from Europe. This includes species for which only single animals are left or only geriatric individuals. There are more species that are likely dead ends due to their small population, but in such cases that is often noted as a “likely dead end” in the species texts, if the respective species is treated at all.
@Joker1706 Waiting for the end, Europe's last mountain anoa
So depending on the family there can be a lot of species that get treated or only a few. This is not a thread with exhaustive species lists of all species kept in Europe. Especially species with a stable presence (either common or rare) will go unmentioned and you can find them on Zootierliste

.
For species that are gained and/or lost from Europe this century there are some symbols after each species name that summarise the history of this species in Europe to quickly differentiate between short term and long term holdings. The symbols are the following:
Number of zoos kept (current and former during the holding period):
A 1 zoo
B 2-5 zoos
C 6-10 zoos
D >10 zoos
Time period kept:
1 < 1 year
2 1-5 years
3 6-10 years
4 11-20 years
5 > 20 years
* Species successfully bred
♱ Dead end (in case of species gained)
↑ Species gaining popularity (in case of species gained)
I will put these indications in a spoiler at the top of each subsequent page for easy reference. I feel that this helps differentiate between the species that have a long versus a short history in Europe. The loss of the mountain paca represents a different thing compared to the loss of the tiger quoll. The former was kept and bred quite widely, where the latter was only held for a short period at a single zoo.
At the end of an order or a group of smaller orders there will be a summarising posts highlighting and analysing overall trends of the covered group(s).
Now is also the final chance to fill in the survey:
https://forms.gle/gz85frchqFGJNcNm7
In a few days I will present the results of the survey as a starting point of zoochat's expectations. After that I will quickly start with what this thread is really all about.