Exercise Bike

Watching in YouTube a video about sparrows in Brazil. They were introduced in Brazil on 19th century brought by Portuguese sailors to garnish the cities. Now their population is decreasing in the big cities. As they have not adapted to life in the rainforests, they were restricted to the cities.
In the last 30 years, pollution in the cities reduced a lot so our native birds came to the cities. They are much more agressive than sparrows so their population is really smaller.