The value of small urban greenspaces for birds in a Mexican city

We explore bird communities in different types of small urban greenspaces (<2 ha) in order to understand which birds occupy these structures, and the habitat and landscape features that affect them. In particular we analyzed how greenspace characteristics (size and vegetation structure), those of the adjacent landscape (area covered by urban structures and vegetation), and human disturbance variables (traffic of pedestrians, vehicles and noise levels) affected bird species richness, abundance and community composition (during summer and winter) in the city of Pachuca, Mexico. We selected 19 small greenspaces (ranging from 0.1 to 2 ha), including public parks, gardens and road strip corridors. We registered 39 species of birds of which 15 were migratory. In general bird species richness was higher in parks and gardens, and lower in road strip corridors, where more noise and traffic was registered. Greenspace area was the most important variable that positively influenced bird species richness, for both the summer and the winter communities. Summer bird species richness was lower in places that had a greater percentage of area covered by buildings in the adjacent landscape. Generalist and opportunistic species were favored by urbanization. Insectivorous species in winter were more abundant in larger greenspaces that had taller trees and more tree and shrub species, and in sites with more vegetative cover in the adjacent landscape. We suggest some management and urban planning actions that would benefit birds within many Latin American cities, where small greenspaces are often the only available refuges for birds.

Research highlights
► Greenspace area was the most important variable that positively influenced bird species richness.
► Bird species richness was higher in parks and gardens, and lower in road strip corridors, where more noise and traffic was registered.
► Summer bird species richness was lower in places that had a greater percentage of area covered by buildings in the adjacent landscape.
► Insectivorous and migratory species in winter were favored by larger greenspaces that had taller trees and more tree and shrub species, and in sites with more vegetative cover in the adjacent landscape.
► Small urban greenspaces (<2 ha) may be the only refuges available for birds in many Latin American cities.