Recent zoology/ecology coined a new term, synurbization, as an analogy to the existing term of wider meaning – “synanthropization.” Synurbization denotes adjustment of wild animal populations to specific conditions of urban environment. The new term, was introduced by theriologists and it is accepted in ornithology as well. The term “urbanization,” in turn, should be in ecology applied for changes in landscape (or environment) caused by urban development. The growing and global tendency towards synurbization, observed recently in animal world, is a response to world-wide expansion of urban development (urbanization). More and more bird and mammal populations colonize cities, and some of them are in urban conditions much more successful than in their native natural habitats. In Europe, the best known examples are black-bird Turdus merula, magpie Pica pica , Hooded crow Corvus corone cornix, kestrel Falco tinnunculus, red squirrel Sciurus vulgaris, Striped field mouse Apodemus agrarius, rabbit O. oryctolagus, red fox V. vulpes. In Warsaw, during the past few decades, at least 12 new birdspecies and 2 mammal species have colonized areas of high degree of urbanization.Synurbic populations show several significant ecological and behavioural differences, as compared with populations of the same species living in their native non-urban habitats. Among most typical features of synurbization are: higher density of population connected with reduction of individual (pair, family) territories, reduced migratory behaviour, prolonged breeding season (even winter broods) and other changes in breeding ecology, prolonged and changed (sometimes adversed) circadian activity, increased longevity (but worse health parameters!), changes in diet and in foraging behaviour, increased intraspecific agression, tameness toward man and various adaptations to human behaviour. All the above adjustments of synurbic populations seem to be within the range of natural plasticity of the species. The question concerning possible genetic differences between synurbic and non-urban populations has no clear answer so far.
The rapid increase of the phenomenon of synurbization, which is observed in recent decades, shows chances for coexistence between wild animals and our urban civilization. It also shows possibilities for managing of wildlife in cities. But it does not change the fact, that a world ecological crisis affects the fauna in cities just as in the animal world as a whole.