Determinants of Local Extinction and Turnover Rates in Urban Bird Communities

Abstract

Studying the effects of urbanization on the dynamics of communities has become a priority for biodiversity conservation. The consequences of urbanization are mainly an increased fragmentation of the original landscapes associated with a decrease in the amount of favorable habitats and an increased pressure of human activities on the remaining patches suitable for wildlife. Patterns of bird species richness have been studied at different levels of urbanization, but little is known about the temporal dynamics of animal communities in urban landscapes. In particular, urbanization is expected to have stronger negative effects on migratory breeding bird communities than on sedentary ones, which should lead to different patterns of change in composition. Using an estimation method accounting for heterogeneity in species detection probability and data collected between 2001 and 2003 within a suburban area near the city of Paris, France, we tested whether these communities differ in their local extinction and turnover rates. We considered the potential effects of patch size and distance to Paris' center as a measure of the degree of urbanization around the patches. As expected, local rates of extinction and turnover were higher for migratory than for sedentary species, and they were negatively related to patch size for migratory species. Mean species richness of the sedentary species increased during the study period and their local turnover rate was negatively related to the distance to the urban core, showing a trend to colonize the most urban patches. These results highlight the very dynamic nature of the composition of some local bird communities in fragmented habitats and help to identify factors affecting colonization and extinction.

Linking bird species traits to vegetation characteristics in a future urban development zone: implications for urban planning

“…Positions of vegetation characteristics and species traits relative to the origin indicate relative contributions to the RLQ axes (plots b and c) recorded species that nest and/or forage arboreally. These species may not persist in a landscape with fewer trees or may face increased inter-specific competition for nest and food resources, possibly leading to local population declines or local extinction (Tilman et al 1994;MacHunter et al 2006;Huste and Boulinier 2007). For example, the loss of patches of hollow-bearing trees may negatively affect hollow-nesting parrots, such as the nationally threatened superb parrot, Polytelis swainsonii (EPBC Act 1999).…”

Ecotypic differentiation between urban and rural populations of the grasshopper Chorthippus brunneus relative to climate and habitat fragmentation

“…But it may also affect organisms in an indirect way through, for example, temperature-related changes in phenology and the available time for reproduction (e.g., Partecke et al 2004;Neil and Wu 2006). Urban areas typically have small and strongly fragmented habitat patches which affect local extinction and turnover rates Communicated by Roland Brandl. (e.g., Husté and Boulinier 2007). The habitat used by organisms in urban areas may also differ in quality from the corresponding habitat in other landscapes.…”

Avian metapopulation dynamics in a fragmented urbanizing landscape

“…Populations of Nearctic-neotropical migrant birds in our system were twice as likely to experience local extinction as were resident species perhaps due to their sensitivity to urbanization. Huste and Boulinier (2007) described a similar pattern of extinction for migrant and resident birds in Paris, France, showing that rates of extinction for migratory birds were significantly higher (residents extinction rate = 0.03±0.01 vs. migrants = 0.20±0.03) than those of resident birds.…”

“…With the sole exception of northern cardinals, every species examined experienced at least one local extinction and colonization event. Extinction rates for bird populations in fragmented systems are quite variable depending on factors such as habitat patch size and quality, and population size within the patch (Bellamy et al 1996;Boulinier et al 2001;Doherty et al 2003;Huste and Boulinier 2007). Unlike others reporting that extinction rates in fragmented or disturbed landscapes can be as much as two times greater than rates of recolonization (Crooks et al 2000) we found that each subpopulation had a 16.6 % chance of extinction with nearly 70 % of extirpated sites being recolonized during the course of our research.…”