The ecological importance of wetlands for aerial insectivores (swifts, martins and swallows) along the Tyrrhenian coast

Abstract

We studied phenology and density of migrant aerial insectivore birds (Riparia riparia, Hirundo rustica, Delichon urbicum, Apus sp.) from a coastal landscape mosaic of central Italy, in order to detect differences in habitat use and seasonal dynamics of each species. Two habitat types were surveyed: wetlands (a mosaic of reed beds and rush beds) and altered habitats, consisting of orchards and urban areas. We used the point count method from January to June, in a set of randomly selected sampling points. A comparison between all species showed that swifts reached the highest mean point density, while sand martin showed the lowest values, mainly in altered habitats. Initially, all the breeding species were numerous in wetlands; subsequently they shifted toward altered habitats (mainly used as breeding sites), where they were observed up to the end of the counts. Along the Tyrrhenian coast, wetlands are exploited as soon as these aerial foragers arrive in the study area and then shift to the surrounding altered (i.e., urbanized or land reclaimed) zones for nesting after some ten-days.

“Accidental” urban wetlands: ecosystem functions in unexpected places

“…; Roach and Grimm ), provision of habitat for key organisms (Arena et al . ; Holzer ), carbon sequestration (Lawrence and Zedler ), and hydrologic functions such as cooling and groundwater recharge (McLaughlin and Cohen ).…”

“…Despite extensive documentation of urbanization impacts on wetlands (Paul and Meyer 2001;Walsh et al 2005;Wenger et al 2009), many studies indicate that remnant and/or modified urban aquatic systems are still capable of performing useful functions (ie those serving key ecosystem services) at relatively high rates or capacities (Ehrenfeld 2004). These functions include nutrient processing and removal (Grimm et al 2005;Ehrenfeld et al 2011;Roach and Grimm 2011), provision of habitat for key organisms (Arena et al 2011;Holzer 2014), carbon sequestration (Lawrence and Zedler 2013), and hydrologic functions such as cooling and groundwater recharge (McLaughlin and Cohen 2013).…”

Seasonal and habitat-related changes in bird assemblage structure: applying a diversity/dominance approach to Mediterranean forests and wetlands

“…Due to these constraints, in winter and spring, natural and semi-natural Mediterranean small wetlands result in strategic stop-over sites and hot-spots for migrant species, both wintering and passage ones: this features allow the coexistence of a large number of birds, also in short periods and in small areas, with high spatial and temporal turnover in richness and composition of species assemblages (e.g. Gonz alez-Gajardo et al 2009;Sebasti an-Gonzalez et al 2010;Arena et al 2011). These processes induce significant differences in slope of lines of diversity/dominance diagrams.…”

Using citizen science to assess drivers of Common House Martin Delichon urbicum breeding performance

“…Freshwater habitats presumably support large numbers of good quality invertebrate prey (Imlay et al 2017). Wetlands are thought to provide important feeding sites for swallows and martins and are exploited before pairs arrive in the surrounding areas, including urbanized landscapes, to nest (Arena et al 2011). Residential houses provide important nest-sites, and areas on the edge of urban areas support a high abundance of aerial invertebrates (Teglhøj, 2018), which is presumably why we found a positive effect of suburban land-use on the probability of House Martin nest success.…”