Functional and ecological diversity of urban birds: Conservation and redesign of biocultural landscapes

Abstract

Urbanization has changed the world's natural ecosystems. Therefore, the study of plants and animals in urbanized landscapes is of interest for the conservation of biodiversity and ecosystem services. Birds have been used as surrogates to study the effects of urbanization on the ecosystem services they provide (e.g., pollination, biological control, seed dispersal). We assessed the ecological and functional diversity of birds in biocultural landscapes of a small city, home to the Mazahua culture, in central Mexico. Biocultural landscapes were characterized in terms of their structure, composition, and associated cultural practices. Monthly avifauna surveys were conducted from April 2020 to March 2021 at four sites per landscape type (i.e., stream, arid tropical scrub, urban orchard, and cropland). Ecological diversity was estimated based on rarefaction and extrapolation curves, and functional diversity was quantified and compared among biocultural landscapes using the multidimensional index of dispersion (FDis) and functional composition (CWM). The biocultural landscapes in our study area harbor 71 bird species distributed among 50 genera and 29 families. Ecological and functional diversity is higher in the biocultural landscapes that contain remnants of native vegetation (i.e., stream, 55 spp., arid tropical scrub, 47 spp.). Stream is the biocultural landscape that has the greatest ecological and functional diversity. In the biocultural landscapes with greater vegetative heterogeneity, the composition of functional traits is dominated by species associated with conserved areas (i.e., insectivore, arboreal, and understory foraging species). Urban development goals should encourage the restoration and preservation of remnant native vegetation. There is also a need to promote biocultural management and the redesign of productive landscapes (i.e., cropland and urban orchards) that conserve species and ecosystem services.