Birds in cities more stress resistant!
Ornithologists at Max Planck Society in Germany have studied and found that the European blackbirds born in a city are more resistant to acute stress than their forest dwelling cousins. The reduced reactivity of the birds probably has a genetic basis which the scientists found. It could be result of urban-specific selection pressures to which birds in the cities are exposed.
Blackbird in the New World, any of several species of songbirds in the family Icteridae, collectively called icterids; also, an Old World thrush (Turdus merula, family Turdidae).
The best known icterid is the red-winged blackbird (Agelaius phoeniceus), which ranges from Canada to the West Indies and Central America. It is 8 in. (20 cm) long, and the male's black plumageis set off by red shoulder patches. The Old World blackbird, 10 in. (25 cm) long, is common in woods and gardens throughout temperate Eurasia as well as in Australia and New Zealand.
Selection is the preferential survival and reproduction or preferential elimination of individuals with certain genotypes, by means of natural or artificial controlling factors.
The theory of evolution by natural selection was proposed by Charles Darwin and Alfred Russel Wallace in 1858. Artificial selection differs from natural selection in that inherited variations in a species are manipulated by humans through controlled breeding in order to create qualities economically or aesthetically desirable to humans, rather than useful to the organism in its natural environment.