Replacement of semi-natural cover with artificial substrates in urban parks causes a decline of house sparrows Passer domesticus in Mediterranean towns

Abstract

Many European towns and cities have undergone reurbanisation processes in recent decades. However, their effects on urban biodiversity have been poorly studied. Currently urbanisation processes include park remodelling, which involves the replacement of semi-natural substrates (natural grass, bare soil) with artificial ones (pavement, concrete, areas for dogs, artificial grass). Our aim was to explore, for the first time, the effects of park remodelling on the trends and abundance of a declining urban exploiter, the House Sparrow. An abundance index of House Sparrows was obtained in 32 urban parks of four towns in the Valencian Community (Spain) in four summers (2015)(2016)(2017)(2018). Of the studied parks, 10 were remodelled during the study period. Before remodelling, the trends and abundance of House Sparrows in both groups of parks were similar and stable on average, which suggest no bias between both park groups. However, House Sparrow abundance was significantly reduced in parks affected by remodelling works while in those non-remodelled it remained stable. Park remodelling might be linked to a reduction in both habitat suitability and availability of trophic resources, which could harm urban House Sparrows populations and possibly other species as well. Therefore, new park policies and urban planning measures are urgently needed to preserve urban House Sparrows.

Green infrastructures and ecological corridors shape avian biodiversity in a small French city

“…Recently, urban management has relied on a 'renaturing of cities' strategy to improve biodiversity, but the relative benefits of alternative policies remain debated (Connop et al 2016;Garmendia et al 2016;Snäll et al 2016). Specifically, it has been suggested that all green spaces do not have similar value in terms of habitat suitability, and that highly fragmented, small, and isolated green spaces may be of limited ecological value relative to larger and more connected green spaces (Beninde et al 2015;Bernat-Ponce et al 2020;Lepczyk et al 2017;Villaseñor et al 2020). In the last decade, the development of connected green infrastructures and ecological corridors has been proposed as a way to improve the colonization of wildlife and, therefore, urban biodiversity (Filazzola et al 2019;Vergnes et al 2013).…”

Effect of replacing surface with underground rubbish containers on urban House Sparrows Passer domesticus

“…First, design and management of green areas should promote weeds, bushes and native plants that harbour important food resources for House sparrows such as invertebrates and seeds (Bernat-Ponce et al 2018;Narango et al 2018). The substitution of grass and soil with impervious substrates such as artificial grass and concrete has been shown to affect negatively to House sparrows (Bernat-Ponce et al 2020;Verbeeck et al 2011), likely due to the reduction of food resources and thus should be avoided. Second, it is important to promote new urban green areas that work as green stepstones, including parks and private gardens, especially in areas with underground rubbish containers (De Laet and Trappeniers 2019;Shaw et al 2011).…”

“…Urbanisation is increasing all over the world at surprisingly quick rates (Murgui and Hedblom 2017;United Nations 2018). This process affects wildlife in many ways, for example, modifying habitat structure which renders some landscapes unsuitable for several species (Bernat-Ponce et al 2020;Isaksson 2018;Murgui and Hedblom 2017;Verbeeck et al 2011). These modified environments pose a new challenge for urban avifauna through exposure to novel stressors, such as pollutants, noise, new predators, exotic competitors or processed food (Bernat-Ponce et al 2018;Francis and Barber 2013;Herrera-Dueñas et al 2017;Murgui and Hedblom 2017;Schroeder et al 2012).…”

“…A consensus is starting to emerge that considers the increase in human socio-economic status and urban renewal as key factors for the species' urban decline in Europe. First, changes in urban habitats and loss of green urban areas may negatively impact upon natural food availability, such as seeds and invertebrates (Bernat-Ponce et al 2020;Pauleit et al 2005;Vincent 2005). Second, these habitat changes have indirect effects on House Sparrows, such as a rising predation risk by Sparrowhawks (Accipiter nisus) and domestic cats (Felis catus) due to reduced shelter from predators (Bell et al 2010;Shaw et al 2008;Thomas et al 2012).…”

Differential Long-Term Population Responses of Two Closely Related Human-Associated Sparrow Species with Respect to Urbanization

“…Additionally, van Manen [48] indicated that the House Sparrow has currently declined most heavily in highly urbanized areas in the Netherlands, and in Spain, the species decrease has been linked with the high-impact urban development [82]. In general, changes in land use practices and local habitat characteristics may influence the sparrow's occurrence and abundance [42,[83][84][85][86][87]. However, we are not able to study these topics in more detail, but obviously, there can be some differences between the sparrow's winter and breeding season habitat use that will serve further research.…”