Taxa Richness Differences in European Zoos between 1959 and 2016: Establishment Period and the Iron Curtain Matter

Zoos represent a social construct, whose form is influenced by societal development. During the 20th and at the beginning of the 21st century, they have been transformed from assembled collections to internationally managed insurance (ex situ) populations, and these transformations required some changes in taxa numbers and composition. Previous studies have already identified the trend of reducing the number of taxa kept in zoos worldwide. The aim of the present study is to verify this trend in Europe in more detail and therefore to identify the changes in taxa richness and mammalian taxa richness from 1959 to 2016 in the same set of 67 European zoos while considering their opening period (before 1900 and 1900–1960) and location with respect to the former Iron Curtain (Eastern vs. Western Bloc). There was no significant decrease in taxa richness; on the contrary, there was a significant increase in taxa richness for the former Eastern Bloc zoos. There was a significant decrease in mammalian taxa richness for zoos opened before 1900 and those of the former Western Bloc. These results demonstrate that mammalian taxa have declined in numbers to some extent and that the decline mostly concerns older zoos and those that have historically reached a different stage of development. This suggests that European zoos have not been subject to trends uniformly and should apply different and appropriate strategies when facing future (not only conservation) challenges.