Unique biotic heritage [%new%]
The team analyses the data and found that cities retained about just 8% of bird species and 25% of plant species of comparable undeveloped land.
But Dr Aronson added: “Contrary to popular belief, we show that the plants and birds of cities are not all the same across the world.
“Owing to the fact that cities around the world share similar structural characteristics – buildings, roads etc – it is thought that cities share a similar biota no matter where they are in the world.
“Few species are shared across cities, such as pigeons and annual meadow grass, but overall, the composition of cities reflects the unique biotic heritage of their geographic location.”
She said that the data revealed that, overall, cities supported close to 20% of the world’s bird species and 5% of known plant species.
“Conserving green spaces, restoring natural plant species and adding biodiversity friendly habitats within urban landscapes could, in turn, support more bird and plant species,” Dr Aronson suggested.
Commenting on the study’s findings, Prof Philip James from the University of Salford – who was not involved in the research – said that many cities grew in areas that were diverse and rich in terms of natural resources, and plants and animals.
“So the challenge is to use our knowledge of urban ecology to enrich the lives of the ever increasing number of people living and working in cities,” he told BBC News.
“Seeing birds from our windows, hearing their songs and having pleasant, natural places to walk are all beneficial to our health and well-being.”
Dr Aronson said that by improving the understanding the ecology found in urban areas, city planners and managers would be better placed to preserve and promote biodiversity, which provides important ecosystem services, such as water quality and flood protection.
She added: “Of course this is a coarse-scale study but we still come up with patterns that are similar in cities around the world.”