Highly read on Proc. R. Soc. B online in February

Most bird and plant species in cities are native to those areas, but their numbers are rapidly decreasing around the world.

Myla Aronson at Rutgers University in New Brunswick, New Jersey, and her colleagues compiled and analysed data for birds in 54 cities and for plants in 110 cities, mainly in North America and Europe — the largest collection of urban biodiversity data so far.

The authors found that cities support just 8% of bird species and 25% of plant species that are found in non-urban areas. Human-related factors, such as land use and city age, seem to have a greater effect on bird and plant populations than do natural factors such as climate and geography.

Urban planning that emphasizes native habitats could better support biodiversity, the authors say.

Proc. R. Soc. B 281, 20133330 (2014)