This article summarizes available data on the free-living population of the Barbary Sheep (Ammotragus lervia) in the Plzeň District in the 1970s to 1990s. This population originated through repeated escapes of the Barbary Sheep from the Plzeň Zoo (1972–87). The Barbary Sheep appeared to be viable in the wild, and its free-living population ceased to exist not before 1994. Additionally, a short review of the Barbary Sheep stock in Czech zoos is presented (1985–2011). and Miloš Anděra, Lenka Václavová.
Cuckoos parasitize many rare and inconspicuous host species but avoid other common and conspicuous ones. In this article, results of a study that solved this long-standing ecological conundrum are described. I use this work to illustrate va - rious weaknesses of typical ecological studies (sample size, data representativeness, reification) and give suggestions for a better research practice in the future. and Jiří Klimeš, Ivan Literák.