Synurbization – adaptation of animal wildlife to urban development. Term created by theriologists – ecologists. It denotes an adjustment animal populations to specific conditions of the urban environment, in the connection with regular existence there in the wild state. The term is not applied to individual animals which have come to an urban area accidentally and witch live there for limiter time. Synurbization is related to two other terms used in the field : synanthropization (refers to the adaptation of animal populations to human – created conditions in general )and urbanization (refers to changes in landscape coursed by urban development).
The phenomenon of synurbization has been described mainly for birds and mammals, but it is known also in other animal groups(e.g. amphibians). Examples of synurbization of mammal in European cities are provided by :the squirrel (Sciurus vulgaris)
the striped field mouse
the red fox (Vulpes vulpes)
the stone marten (Martes foina)
the badger (Meles meles)
Processes of synurbization also concern wild populations of birds introduced to cities by man . The best known example is the peregrine falcon (Falco peregrinus), which has been successfully introduced, in the last two decades, to cities in North America and in Germany, as well as Prague, Warsaw and Moscow.
Adaptation to urban ecological niches requires changes in the behavior and ecology of synurbic populations, in comparison with non – urban ones. Several studies indicate that the most characteristic adjustments of synurbic populations are the following:Living at much higher population density, connected with a reduction in the size of individual (pair, family) territories -less pressure from enemies in the city and the spatial limitations of suitable sites (green island)surrounded by built up areas.
Reduced migratory behavior connected with better possibilities for wintering in cities.
Prolonged breeding season, mainly allowed by a sedentary life and favorable microclimate.
Greater longevity connected with better winter survival due to favorable food and climatic conditions, and a reduction of migrations, which are more dangerous and more exhausting than sedentary life.
Prolonged circadian activity – may be connected with artificial lighting or the tendency to spend the hours of most intense human activity in shelters.
Changes in nesting habits, including the use of a variety of anthropogenic objects as shelters, nesting places and material for nests.
Changes in feeding behavior - a city offers rich resources of anthropogenic food, which are attractive to many bird and mammal species.
Tameness toward people - animals often follow people begging for food, or even sit on people.
Increased intra – specific aggression is observed in synurbic populations, a tendency connected with the high density of individual territories and spatial limitations.
The main consequence of urban development for wildlife is a decrease in its species and ecological diversity. The growing tendency towards synurbization observed in birds and mammals is a chance for enriching diversity of urban wildlife. Synurbization of some species could cause practical problems when their populations grow to high concentrations. An example of such problems is Canada goose in North American cities.