Urbanization, environmental stabilization and temporal persistence of bird species: a view from Latin America

Abstract

Background A scarcely studied consequence of urbanization is the effect of temporal stabilization of the environment on bird communities. This alteration is thought to dampen environmental variations between day and night, seasons and years, promoting a temporal persistence of bird composition in urban areas. The aim of this study was to review current evidence of temporal stabilization of biotic and abiotic factors in urban environments and the potential effects of such stabilization on temporal variation of bird species presence at different temporal scales. Methods I selected the literature by searching published articles and book chapters using Scopus and Google scholar. I only included articles that compared the temporal variation of bird composition or resources between different levels of urbanization. Results In general, there is evidence of temporal stabilization of abiotic and biotic factors at the three time scales considered. At the diurnal scale, the main factor considered was artificial light in the context of light pollution. At the seasonal and interannual scales, several case studies found a smaller temporal variation of primary productivity in urban than in natural and rural areas. Bird species composition showed more stabilization in urban environments at the three temporal scales: (1) several case studies reported bird activity at night, associated with artificial light; (2) studies in urban parks and along urbanization gradients showed smaller seasonal variation of bird composition in the more urbanized areas; and (3) in general, case studies along urbanization gradients showed smaller interannual variation of bird composition in the more urbanized areas, although some studies showed no relationships or opposite trends than expected. Discussion The published evidence suggests that urban areas dampen the natural cycles at several temporal scales. The stabilization of biotic and abiotic factors, such as light, temperature, food and habitat structure, is desynchronized from natural diurnal, seasonal and interannual cycles. However, there is a dearth of long-term comparisons of bird composition and studies that simultaneously analyze the relationship between resources and bird composition stabilization at the seasonal and interannual scales. More research is needed in the Southern hemisphere, where there is a lack of studies dealing with the seasonal and interannual variations of primary productivity along urbanization gradients and nocturnal activity of bird species. A future research agenda should include differentiation of spatial and temporal homogenization of avifaunas.

Large cities and the loss of green areas exclude migrant birds: a global analysis

“…As cities grow, they are characterized by higher levels of car and pedestrian traffic (Leveau and Leveau 2006), which negatively affect migrant proportion and richness (Burger and Gochfeld 1991, Hennings and Edge 2003, Zhou and Chu 2012. Moreover, more isolation of green areas to non-urban areas and a lower seasonality of resources can decrease migrant bird presence (Leveau and Leveau 2006, Leveau 2018. Finally, as cities grow urban green areas can become surrounded by denser urbanization, which may decrease migrant richness and abundance (Friesen et al 1995, Dunford and Freemark 2004, Pennington et al 2005, Rodewald and Matthews 2005, Mason et al 2007.…”

“…Given that migratory species are a substantial part of the seasonal dynamics of bird communities, the loss of migrant proportion in large cities supports the idea that urbanization causes a temporal homogenization of bird communities (Leveau 2018). It is necessary to conduct multiscale studies to get more insights about urban green area use by migratory species, producing the knowledge necessary to foster management strategies that mitigate the negative impacts of cities on migrant species.…”

“…Moreover, migrant species seem more sensitive than resident species to green area size and human disturbance (Burger and Gochfeld 1991, Park and Lee 2000, Zhou and Chu 2012. Given that urban areas tend to have a lower seasonal fluctuation of primary productivity induced by the urban heat island phenomenon, the food resources surplus during spring-summer may be lower than non-urban areas, affecting the presence of migratory species in cities , Leveau 2018). In addition, the urban heat island phenomenon can exacerbate the mismatch between the peak of food availability and the timing of breeding of migrant species.…”

Artificial light is the main driver of nocturnal feeding by the Rock dove (Columba livia) in urban areas

“…Urban areas are characterized by a temporal stabilization of environmental conditions, which is related with a temporal stabilization of species composition (Leveau 2018). For instance, artificial light at night has been postulated as the main driver allowing the colonization of night by diurnal species.…”

“…Conversely, artificial light at night could have negative impacts on nocturnal bird species, limiting their presence in urban areas (Weaving et al 2011). As a result, the increased presence of diurnal birds at night and the local extinction of nocturnal species may lead to a temporal homogenization of bird communities (Leveau 2018).…”