What is biodiversity
"Biodiversity" is a term we use to highlight the richness of the natural world. It describes the great variety of animals and plants, but also habitats and genes. Biodiversity interacts with the natural environment forming ecosystems that support living organisms - like humans. Without the natural environment, which we often take for granted, we cannot survive.
The current loss of biodiversity is extremely alarming, as the present rate of species extinction is estimated to be 100 to 1000 times higher than in the past, and is mainly due to human activity: extinction, degradation, and fragmentation of habitats, invasion of alien species, over-exploitation of natural resources and species, pollution, climate change.
All over the planet, there are evident signs of biodiversity
Wild animals face great challenges to their survival due to both natural and non- natural causes. The main causes of wild animal injuries are road kills, bait poisonings, poaching, electrocutions, in the case of birds, forest wildfires, habitat fragmentation, overexploitation of natural resources.
Also, very often exhausted wild birds are being received by the wild animals' rehabilitation centers, mainly during spring migration or due to extreme weather conditions. It has also been reported that wild animals are victims of infectious disease outbreaks within the cities. Finally, another very important threat is wild animal captivity that feeds illegal wildlife trade.
Wildlife in the city
The presence of birds is obvious in modern cities. The doves, which are descendants of the wild doves, as well as the sparrows, are the most commonly found birds in the cities since they are very well adapted to live close to humans. Other bird species (e.g. the blackbirds) seek for more natural areas, such as parks, or quieter locations, such as abandoned buildings or ruins, which are preferred by owls.
Some species are looking for a warm place within the cities to winter. Birds like finches, robins, white wagtails, tits, black redstarts, and starlings can be easily seen in the city during winter. Other species (such as starlings, magpies, jackdaws and hooded crows) feed on the urban fringes, while at dusk come to the cities to spend the night. They choose tall trees, where large herds roost side by side until dawn.
Illegal dumps and landfills, which are filled by our wasteful society, attract seagulls. Also in search of food, various birds of prey such as the sparrowhawks follow the starlings during the winter, while the peregrine falcons choose the tall urban buildings hoping for a meal of doves and collared doves who nest and feed there.
Besides birds, other animals such as bats, hedgehogs, turtles, and foxes find food and shelter in the city. Also, various snakes, the vast majority of which are harmless.